CORE One+ Step-by-Step Build

1Introduction difficulty◷ 15-20 min15 stepsofficial ↗0/15›

STEP 1 Preparing the kit

Welcome to the guide for assembling setting up your Prusa CORE One+ kit. Follow these steps to ensure your printer is ready for its first print.
No soldering or wire crimping is required.

STEP 2 How to navigate through the manual

Use the graphical navigation buttons in the bottom right corner or the arrow keys on your keyboard:
Play backward button / Up arrow key - Moves to the previous step.
Left arrow button / Left arrow key - Moves to the previous image, or to the previous step if it’s the first image in the step.
Next button / Right arrow key - Moves to the next image, or to the next step if it’s the last image in the step.
Play forward (Next) button / Down arrow key - Moves to the next step.
Click on Contents to expand the full list of steps in this guide. This allows you to jump to any step regardless of the sequence.
Click on Comments to open the discussion for a specific step and leave your feedback.

STEP 3 View high resolution images

When you browse the guide on help.prusa3d.com, you can view the original images in high resolution for clarity.
Just click on the image to open it in high resolution for a detailed view.
Click on Fullscreen mode or press the F key to maximize your screen space and focus entirely on the instructions.

STEP 4 All the required tools are included

Tool package includes:
Tools can be found in Electronics & fasteners package.
Needle-nose pliers (1x)
Philips (PH2) screwdriver (1x)
Universal wrench (1x)
Wrench size 13-16 mm (1x)
Allen key set Torx key set

STEP 5 Additional utilities for this guide

Some steps in the manual will require commonly available items to help you with assembly (not included in the kit):
Paper towels or a piece of cloth - For wiping preservative oil from the smooth rods and linear rail.
Scissors - For cutting a bag with bearings Lubricant (included in the kit) - For lubricating the planetary gear in the Nextruder (print head).

STEP 6 Labels guide

All the boxes and bags including parts for the build are labeled.
The labels include the list of contents and part count.
You can download a Cheatsheet with 1:1 fastener drawings from our site prusa.io/core-one-cheatsheet. Print it at 100 %, don't rescale it, otherwise, it won't work.
For PRUSA veterans: Fasteners are divided into individual bags according to its type. Not into packages for individual chapters, as it was with previous printers.
The instructions will specify the package for each part, with the exception of fasteners, which are always located in the Fasteners package.

STEP 7 Spare bag

Spare fasteners are included in each bag of fasteners. The amount of spare is always included in the total number shown on the bag.
Similarly, some parts may include one extra piece in the same bag.

STEP 8 Printed parts - versioning

Most of the 3D printed parts on Prusa CORE One+ are marked with their version.
E, F and Gx series (e.g. E1) - those parts are printed on Prusa Research farm and are distributed with the kit.
R, S and Tx series (e.g. R1) - those parts are available for download at printables.com. They are identical to the factory ones.
The numbers indicate minor revisions that usually involve small design tweaks. A different label in the manual (e.g., a different version shown in photos) does not affect the assembly – all versions are fully compatible.
However, if a specific revision requires a different assembly procedure, we will clearly highlight it in the manual and explain the differences.
In case you have issues while assembling the printer with the certain printed part, please try to find this label and tell it to our support team.

STEP 9 We are here for you!

Lost in the instructions, missing screw or cracked printed part? Let us know!
You can contact us using the following channels:
Using comments under each step.
Using our 24/7 live chat here at help.prusa3d.com Writing an email to info@prusa3d.com

STEP 10 Pro tip: inserting the nuts

3D printed parts are very precise, however, there still might be a tolerance in the printed part and the same goes for the size of the nut.
Therefore it might happen, that the nut won't fit easily in or might be falling out.
Let's see, how to fix it:
Nut won't fit in: use a screw with a thread along its entire length (typically:
M3x10, M3x18) and screw it from the opposite side of the opening. While tightening the screw, the nut will be pulled in. Remove the screw afterwards.
Nut keeps falling out: Use a piece of tape to fix the nut temporarily in place, as soon as you insert the screw in, you can remove the tape. Using glue isn't recommended as it can partly reach into the thread and you won't be able to tighten the screw properly.
Every time we recommend using the "screw pulling technique", you will be reminded with Joe's avatar ;)
Parts in the pictures are used as an example.

STEP 11 Important: Electronics protection

Here are some tips to prevent damage to the electronics:
Keep the electronics inside the ESD bag right until you are asked to install them.
Always touch the sides of the board only while handling it. Avoid touching the components on the surface.
Before you touch the electronics use any conductive (metal) structure nearby to neutralize the possible static charge from your hands.
Be extra cautious in rooms with carpets, which are often a source of electrostatic energy.
Clothes made of wool or certain synthetic fabrics can easily gather static electricity too. It is safer to wear cotton clothing for the assembly.

WARNING: Make sure to protect the electronics against electrostatic discharge (ESD). Always unpack the electronics right before you need them!

STEP 12 Reward yourself

Building the CORE One+ is a rewarding experience. After finishing each chapter, reward yourself. There is a bag of Haribo bears in the box just for that!
The biggest issue from our experience (MK4S, MK4, MK3S+, MK3S, MK3, MK2S, ...) is inadequate bear consumption. Many of you didn't have enough gummy bears for all chapters, some even ate them all before they started!
After years of thorough scientific research, we came to a solution => At the end of each chapter, you will be told a specific amount of bears to consume.
Eating an incorrect amount than prescribed in the manual might lead to a sudden boost of energy. Please consult a professional in the closest candy store.
Hide the Haribo for now! From our experience, an unattended bag with sweets will suddenly disappear. Confirmed by multiple cases all around the World.

STEP 13 How to successfully finish the assembly

To successfully finish the CORE One+ kit please follow all these:
Always read all the instructions at the current step first, it will help you to understand what you need to do. Don't cut or trim unless you are told to!!!
Don't follow pictures only! It is not enough, the written instructions are as brief as they could be. Read them!
Read the comments from the other users, they are great sources of ideas. We read them too and based on your feedback improved the manual and the entire assembly.
Use a reasonable force, the printed parts are tough, but not unbreakable. If it doesn't fit, check your approach twice.
Eat the gummy bears as instructed! Disobedience won't be tolerated :D Most importantly: Enjoy the build, and have fun. Cooperate with your kids, friends or partners.

STEP 14 Prepare your desk

Tidy up your desk! Tidying up decreases the probability of losing small parts.
Clear your workspace. Make sure you have enough room. A nice clear flat workbench will get you the results you are aiming for.
Let there be light! Make sure you are in a well-lit environment. Another lamp or even an extra flashlight will probably come in handy.
Prepare something to contain the plastic bags and the removed packing materials so you can recycle them afterwards. Make sure there are no important parts being discarded.
A minimum working space of 1.5 × 1.5 meters (60 × 60 inches) is recommended.
It’s highly recommended to place a soft pad on your workbench. Some sheet metal parts have sharp edges that could scratch the surface.
You can use a piece of cardboard as a protective pad.
OK, we are ready. Let's start! Go to chapter 2. Frame assembly

STEP 15 Installing the add-ons and upgrades

This information applies to users planning to install upgrades and add-ons, such as Buddy Camera, an advanced filtration system, and MMU3 in the future.
Before installing any add-ons and upgrades, it is essential to completely assemble and test your printer. Once the printer is fully functional, follow the separate MMU3 or add-on assembly manuals to modify the printer for installation.

2Base assembly difficulty◷ 45-75 min22 stepsofficial ↗0/22›

STEP 1 Tools necessary for this chapter

Wrench 13-16 2.5mm Allen key T10 torx key / T10 torx screwdriver

You can find the tools in the box labeled: 2. Electronics & Fasteners.

STEP 2 Base assembly: parts preparation

Prepare

Bottom panel x1

STEP 3 Inserting the zip ties

Turn the bottom panel so that the bends of the plate are facing upwards.
Note the twin holes for the zip ties around the perimeter of the panel.
Insert six zip ties through the holes, placing them along both sides and partially tightening them, engaging only the first few teeth.
doesn't matter.

Do not fully tighten them yet, as we will route cables through them later.

Note: The orientation of the zip tie heads (inside or outside the metal sheet)

STEP 4 Base assembly: parts preparation (part 1)

Prepare

Z-axis left motor x2

One Z-axis left motor is packed separately in the Electronics & chamber parts package.
For now, keep the trapezoidal nuts in the motor package.
Z-axis right motor (1x) found in the Motor kit package.

STEP 5 Base assembly: parts preparation (part 2)

Z-motor-mount (3x) found in the Printed parts package.
Motor washer (3x) found in the Electronics & Chamber parts package.
The new version of the Z-motor-mount was released in 05/2026.
Z-rod-mount (2x) found in the Printed parts package.
M3x8 screw (24x) found in the Fasteners (3/3) package.

Important: If the Motor washers are not included in your package, your kit contains the new version of the Z-motor-mount, which does not require Motor washers.

STEP 6 Installing the motor mounts

Try to rotate the threaded rods on each Z motor to make sure they are not completely blocked in rotation.
Attach one transparent motor washer pad on each Z motor.
Place one Z-motor-mount on each motor washer. The protrusions on the part must be facing upwards.
Align holes with all the parts.
Join all parts together with four M3x8 screws.
Follow the same procedure for all motors.

STEP 7 Installing the rear motor

Turn the bottom panel upside down.
Locate the circle hole in the middle of the panel back side.
Take the Z motor right - the motor with the longest cable. Labeled ZR on the cable.
Push the motor threaded rod through the panel and align the holes in the panel with the holes in the motor assembly.
The motor cable must point outwards (towards you).
Push both Z-axis motor left through the bottom panel.
The motor cables must point to the rear motor side.
In the following instructions, we will refer to the front and rear sides of the assembly. The front side has TWO motors, while the rear side has ONE motor. We will remind you along the way, but it’s good to keep this in mind :).

STEP 8 Securing the rear motor

Begin securing the motors, starting from the rear motor.
Insert and fully tighten four M3x8 screws into the rear motor.

Make sure the screws stay straight and do not tilt as you tighten them.

Do not overtighten the screws, as they thread directly into the plastic part. For a final tightening, use the shorter part of the key as a handle to apply the correct amount of torque.

STEP 9 Installing the front motor right

Check the Z-rod-mount printed parts for any imperfections. It has to be completely clean inside for the smooth rod to be inserted later on.
To ensure that the smooth rods will fit in perfectly later on, you can check by inserting any of the smooth rods (found in the Rods box) into the Z-rod-mount now.
Insert the Z-rod-mount into the opening next to the front right Z motor.
Use the 13-16 wrench to rotate the rod mount 90 degrees, locking it into place.
Secure the motor using four M3x8 screws. Tighten them completely.

Make sure the screws stay straight and do not tilt as you tighten them.

STEP 10 Installing the front motor left

Let's move to the front left motor (from the front view).
Insert the rod-mount into the opening next to the front right Z motor.
Use the 13-16 wrench to rotate the rod mount 90 degrees, locking it into place.
Secure the motor using four M3x8 screws. Tighten them completely.
Place the whole assembly aside for a while.

Ensure, the motor cable still points to the rear side.

Make sure the screws stay straight and do not tilt as you tighten them.

STEP 11 Bottom frame: parts preparation

Be very careful when handling sharp sheet metal parts to avoid injury or damage.
Metal sheet profiles may look identical at first glance, but there are some differences. DOUBLE-CHECK to pick the correct ones.
Front profile (1x) notice the cutouts - found in the Metal parts 1/3 package Rear profile (1x) with two holes on the flat side - found in the Metal parts 1/3 package Universal profile (2x) no holes on the flat side - found in the Metal parts 1/3 package Spacer pin (2x) found in the Electronics & Fasteners package M3x4rT screw (4x)

STEP 12 Assembling the bottom profile: front + left

Be very careful when handling sharp sheet metal parts to avoid injury or damage.
Place the front profile according to the picture. The cutouts must be facing you.
Place one of the universal profiles on the left side. Orient the part according to the picture. Use the flange as a guide.
Attach the two profiles together.
The flange of the front plate (blue arrow) must be inserted under the left universal profile (green arrow), not on top of it.
Align the holes in both parts.
Join both parts together with the M3x4rT screw.

STEP 13 Assembling the bottom profile: left + rear

According to the picture, place the rear profile (with two holes on the flat side) to the universal left profile. Orient the part according to the picture. Use the flange as a guide.
Join the rear profile with the universal left profile together.
Align the holes in both parts.
Join both parts together with the M3x4rT screw.

Make sure the flange is under the rear profile, not on top.

STEP 14 Assembling the bottom profile: right

Attach the universal right profile between the rear and front profile. Ensure that:
The rear end is above the rear profile flange.
The front flange is inserted under the front profile.
Secure the left profile with M3x4rT on both ends.

STEP 15 Inserting the spacer pins

Insert the spacer pin into the hole in the front profile protrusion.
Push firmly on the spacer pin so that it fits perfectly into the hole.
Use the same procedure for the second spacer pin.

STEP 16 Anti-vibration feet: parts preparation

Prepare

Anti-vibration foot x4

STEP 17 Installing the anti-vibration feet

Place the bottom frame according to the picture. The front profile must be facing you.
Before applying the anti-vibration feet, wipe the metal profiles with isopropyl alcohol and let them dry. This ensures proper adhesion.
Peel off the protective layer from all anti-vibration feet.
Carefully peel off only the protective film from each anti-vibration foot. If the adhesive layer starts to come off with the film, stop and peel from a different corner.
In case the adhesive is not sufficient, we recommend installing the feet as one of the last steps. Alternatively, you can use a 3M VHB tape to ensure that the feet will stick.
Stick one anti-vibration foot in each corner of the frame. Align it with the outer edge of the flat side of the profile.

STEP 18 Installing the bottom frame

Turn the bottom frame upside down. The front profile must be facing you.
Attach the rear side of the bottom panel assembly to the rear side of the bottom frame.
aligns with the front profile of the bottom frame (with cutouts).
Place all the motor cables inside the center area of the bottom frame to prevent pinching.
Slowly and carefully lower the bottom panel assembly into the bottom profile.

Ensure that the front side of the bottom panel assembly (with two motors)

Ensure the assembly fits completely inside the bottom profile.

Make sure no part of the bottom panel assembly extends outside the bottom frame Double-check that no cables are pinched.

STEP 19 Mounting the bottom frame: right side

Focus on the front right corner and right side.
Slightly lift one of the corners of the bottom panel assembly.
Align the threaded hole in the bottom panel with the hole in the profile.
To make it easier to assemble the base, turn the assembly on each side to view hole alignment without fighting gravity. Insert an Allen key in the next hole to maintain alignment.
Join both parts together with the M3x4rT screw.
Move to the rear corner of the right side.
Align the holes in the base and the profile and secure it with the M3x4rT screw.

STEP 20 Mounting the bottom frame: rear + left + front

Move to the rear side of the assembly (side with one Z motor).
Align holes in the base assembly and the profile and secure it with two M3x4rT screws.
Focus on the left side of the assembly.
Align holes in the base assembly and the profile and secure it with two M3x4rT screws.
Turn the assembly with the front profile facing you (profile with cutouts).
Align holes in the base assembly with the profile and secure them using two M3x4rT screws.

STEP 21 Haribo time

It’s time to reward yourself!
Stack your gummy bears in eight rows.
Arrange the number of gummy bears in each row as shown in the picture.
If you don’t get the exact number in the last row, we recommend finding the nearest candy store and buying the missing ones.
Eat the first row.

STEP 22 Done

Congratulations! You just assembled the base assembly.
Set the assembly aside for now and let's move to the next chapter.

3Back assembly difficulty◷ 1.5-2.5 hr53 stepsofficial ↗0/53›

STEP 1 Tools necessary for this chapter

Philips (PH2) screwdriver Needle-nose pliers 2.5mm Allen key T10 torx key / T10 torx screwdriver

STEP 2 PSU assembly: parts preparation

Prepare

Delta PSU 240 W 24 V x1

STEP 3 Preparing the PSU

Insert two M4x6r screws into the left side of the PSU. Do not tighten them completely. Leave at least a 4 mm (0.16 in) gap between the screw head and the PSU.
Slightly loosen all four power terminal screws on the PSU. Do not remove them.
3-4 turns are enough.

STEP 4 Power cables info

In the following steps, we will be connecting the power cables one by one. The terminal screws are installed on the PSU already. Loosen them but don't remove them completely so they don't get mixed up with the other type of screws used on the xBuddy board side of the cable. Each of the two power cables has two leads.
One has a prevailing red color = positive / + One has a prevailing black color = negative / -
Positive (V+)
Positive (V+)
Negative (V-)
Negative (V-)
The red cable (positive) may have a black stripe on it. Similarly, the black cable (negative) can have a red stripe on it.

Note that the power cables have different connectors on each end. For now, prepare the U-shaped connectors (crimping tube color may vary).

Note that the polarity of the terminals on the PSU is:

Do not connect any cables yet, wait until you have been prompted.

STEP 5 Connecting the PSU

Take the RED wire and slide the fork connector all the way into the first (positive)
terminal from the left on the bottom of the PSU. Make sure the steel washer is above the "fork" connector.
Tighten the terminal screw firmly.
Use the same procedure to connect the second red wire to the second terminal slot from the left.
Connect two black wires to the third and fourth terminal slots using the same procedure.
Plug the power panic cable to the right most connector.
Put the assembly aside for a while.

STEP 6 xBuddy: parts preparation I.

Prepare

CORE One xBuddy box x1M3x6 screw x9

The list continues in the next step...

STEP 7 xBuddy: parts preparation II.

xBuddy extension board (1x) found in the Electronics & chamber package xBuddy board (1x) found in the Electronics package xBuddy extension cable (1x) found in the Electronics & Fasteners package Assembly-multi-tool (1x) found in the Printed parts package

STEP 8 Applying the thermal pads

Peel off the white protective layer from all thermal pads.
Always touch the sides of the electronics board while manipulating it. Avoid touching the chips, capacitors and other parts of the electronics.
Attach the pads onto the back of the xBuddy board. There are markings that indicate the correct size and positions.
The surface to which the pads are sticked must be cleaned of grease. This will ensure better adhesion.
For the protection of the board's electronic components, we strongly recommend placing the xBuddy board on the soft pad. You can use the original xBuddy bubble wrap package.
Peel off the blue protective layer from all thermal pads.

Pro tip: If the edge of the layer is difficult to lift, you can use the thin side of the Assembly-multi-tool to help separate the protective layer.

STEP 9 Installing the xBuddy

Always touch the sides of the electronics board while manipulating it. Avoid touching the chips, capacitors and other parts of the electronics.
Insert the xBuddy board to the xBuddy box.
Before fully attaching it completely, center the holes in the board with the holes (columns) in the xBuddy box This opening will remain empty; it is only highlighted for the alignment of the board.
Fix the position of the xBuddy board by inserting five M3x6 screws. Do not fully tighten the screws. A few turns are enough for now.
Put aside your instinct and leave the hole on the bottom right empty.
Fully tighten all five screws. But very carefully, otherwise you can damage the electronics board.

Make sure the Ethernet connector is properly inserted into the hole in the xBuddy box.

STEP 10 Installing the xBuddy extension

Insert the xBuddy extenstion board to the xBuddy box above the xBuddy board.
Before fully attaching it completely, center the holes in the board with the holes (columns) in the xBuddy box.
Fix the position of the xBuddy extension board by inserting four M3x6 screws.
Tighten them completely.

Notice the part orientation.

STEP 11 Installing zip ties

Take a closer look at to the xBuddy box. There are six perforations on the metal case.
Proceed very carefully. Be careful not to damage the connectors or capacitors on the xBuddy board.
Attach the hook on the Assembly-multi-tool below the first perforation on the left.
Bend the tip of the zip tie slightly, approx. 30 degrees. It will be easier to insert correctly even without the Assembly-multi-tool.
Push the zip tie through the perforation and into the Assembly-multi-tool. It will guide the zip tie into the electronics box.
Note the correct orientation of the zip tie. The teeth on the zip tie must be on the visible side.
Repeat the process at the indicated perforations.
Skip the third and sixth perforations.

STEP 12 Connecting the xBuddy extension board

Plug the xBuddy extension connector with the free red cable to the xBuddy extension board.
Leave the red cable free for now.
Plug the other end of the xBuddy extension cable to the xBuddy board.

STEP 13 Inserting grommets: xBuddy box

Insert both grommets into both circle holes in the xBuddy box.
Gently compress the grommet and fit it into the metal sheet, ensuring the groove locks into place

STEP 14 Wi-Fi: parts preparation

Prepare

ESP-WiFi x1M3x6 screw x2

STEP 15 Assembling the Wi-Fi

Insert two M3x6 screw to the xBuddy box assembly from the right side. Do not tighten them completely. Leave at least a 4 mm (0.16 in) gap.
Insert the ESP-WiFi module into the WiFi-cover, positioning it just below the bridge on the left side.
On the other side, ensure the connector fits correctly into the hole in the cover.
Insert the M3x12 screw into this opening in the xBuddy box assembly. If it is too tight, use an Allen key/screwdriver to carefully widen it so the screw fits snugly in the next step.

STEP 16 Installing the Wi-Fi assembly

Be very careful when handling and connecting the ESP module to avoid bending and damaging the pins.
First, insert the M3x12 screw into the opening in the xBuddy box and screw it in to ensure that there will be no issues later on in this step. Then remove the screw.
Then, take the WiFi cover assembly and connect the ESP module pins to the connector in the xBuddy.
Attach the WiFi cover carefully, ensuring the pins of the ESP module are properly engaged in the connector on the xBuddy.
Secure the cover with the M3x12 screw.
Put the assembly aside for a while.

STEP 17 Back panel: parts preparation

Prepare

Back panel x1

STEP 18 Installing grommets: back panel top

Position the back panel as shown in the first image. Use the two oval holes as a reference.
Insert the sealing plug into the center hole.
The sealing plug is not symmetrical. Insert the side with the smaller diameter facing downward.
Insert one small grommet to the left circle hole.
Insert one small grommet into the oval hole.

STEP 19 Installing grommets: sides + bottom

Focus on the left top side of the back panel and locate two oval holes.
Insert one large grommet into the oval hole closest to the corner.
Move to the right top side of the back panel and insert one large grommet to the oval hole.

STEP 20 Aligning the PSU

Carefully insert the PSU into the rear panel pocket.
Align the screws on the PSU to the holes on the left side of the back panel.
Slide the PSU so that the screws go through the holes.

Do not insert the PSU cables into any opening in the rear panel. Leave them hanging over the rear panel until you are instructed to connect them to the Buddy board later on.

STEP 21 Mounting the PSU

Gently slide the PSU so that the position of the screws moves to the end position of the keyhole-shaped holes.
Maintain the PSU position and fully tighten both screws.

STEP 22 Aligning the xBuddy box assembly

Carefully insert the xBuddy box assembly into the rear panel pocket.
Align the screws on the xBuddy box to the holes on the right side of the back panel.
Slide the xBuddy box so that the screws go through the holes.

STEP 23 Mounting the xBuddy box

Gently slide the xBuddy box assembly so that the position of the screws moves to the end position of the keyhole-shaped holes.
Maintain the xBuddy box position and fully tighten both screws.
Fix the PSU and xBuddy box assembly to the back panel by tightening two M3x4rT screws.

STEP 24 Power cables cover: parts preparation

Prepare

PSU-cable-cover x1M3x10rT screw x26-32 Power Terminal Screw x4

STEP 25 Connecting the power cables

Take one red cable leading from the PSU and connect it to the first left terminal slot on the xBuddy board using the 6/32" terminal screw. Tighten it firmly but gently.
Connect the black PSU cable from the same pair as the red one to the second terminal using the 6/32" terminal screw. Tighten the screws firmly.
Take the second red cable from the PSU and attach it to the red cable leading from the extension board. Note the detail. Secure these two cables with the terminal screw in the third terminal slot.
Guide the xBuddy extension cable carefully between the fuses, ensuring it is positioned securely without pressing against them.
Connect the second black PSU cable to the xBuddy, ensuring it does not obstruct the threaded hole.
Route the power panic cable to the xBuddy box and connect it to the bottom right slot on the xBuddy board. Make several loops from the excess cable above the slot.
Arrange the PSU cables as shown, ensuring that no obstructions are around the threaded holes in the PSU and xBuddy box.

Note that the "L" shape of the cable connector must always "undercut" the head of the terminal screw.

Note that from early 2025, the fuses are different. Significantly smaller, white, and embedded in the fuse slot in the xBuddy board, so as not to obstruct the cables.

STEP 26 Preparing the PSU-cable-cover

Insert one M3nS nut into the hole on each end of the PSU-cable-cover.

Ensure the holes are aligned.

STEP 27 Covering the PSU cables

Attach the PSU-cable-cover on the PSU cables.
Secure the cover with two M3x10rT screws in the outermost holes of the part.

STEP 28 Chamber fans: parts preparation

Prepare

Fan grid x1

The assembly process remains exactly the same for both versions. Please refer to the pictures in the next step to see how the new version looks and how to properly route the cables.
Chamber thermistor 260 mm (1x) found in the Electronics & Chamber parts package Zip tie (1x)
Cooling fan (2x) found in the Electronics & Chamber parts package M3x30 screw (4x)

STEP 29 New fan cover - visual reference

The images in this step are for visual reference only. The assembly procedure for the new enclosing fan cover is exactly the same as the older version.
When assembling, pay close attention to the orientation. Unlike the older version where both sides were the same, the new fan cover has a specific inside and outside.
The second image shows the fans and proper cable routing fully installed under the new cover. It is intended for visual reference only and does not change the assembly procedure.
This step is for visual reference only. Do not assemble any parts until instructed in the following steps.

STEP 30 Assembling the fan grid

Guide the thermistor cable under the grid. Thread it in the direction shown in the picture.
The older (flat) fan grid has identical sides. If you have the new fan cover, use the inside of the cover as shown in the previous visual reference step.
Leave the whole thermistor part sticking out.
Turn the grid over and push the zip tie through the pair of holes on the grid's protrusion.
Route the thermistor cable in between the zip tie parts.
Carefully secure the thermistor cable by tightening the zip tie. Do not use excessive force and do not overtighten the zip tie! It may damage the cable.

Make sure that the pawl of the zip tie is located on the opposite side of the thermistor.

STEP 31 Attaching the fans

Place and orient the back panel according to the picture. The grid cutouts must be facing you.
Place both fans to the grid in the back panel.
The side of the fan without the sticker must be facing up.
Orient the fans so that the cables run from the corners in the centre.
Let the cables hang freely for now, ensuring they are not pinched during handling.

STEP 32 Covering the cooling fans

Place the fan grid assembly on the cooling fans.
Align holes in the fans, fan grid and the back panel.
Secure the fan assembly to the back panel with four M3x30 screws.

Make sure that the thermistor is pointing up and its cable runs under the grid.

Do not overtighten the screws to avoid damaging the grid.

STEP 33 Rear profiles: parts preparation

Prepare

Rear profile x2

Nylon rivet (11x)
M3x4rT screw (4x)
2.9x6.5sT self-tapping screw (1x) from the Electronics and Fasteners Package

Note that the other two longer ones differ by having cutouts.

STEP 34 Installing the rear profiles

Take the bottom assembly and turn it so the rear side (with one motor in the center)
faces you.
Focus on the right rear corner—the side with the longest oval opening in the bottom panel.
Attach the rear profile to the right corner, using the end without flanges.
Align the hole on the rear side and secure it with the M3x4rT screw.
Secure the corner on the other side with a second M3x4rT screw - each corner will be secured with two M3x4rT screws.
Proceed the same with the second rear profile on the rear left corner.

STEP 35 Mounting the back panel

Slightly lift the back assembly and gently place it on the base assembly and rear profiles.
Insert one nylon rivet through the rear panel and rear profile on the top right side.
Push the rivet head with your finger until it is fully seated.
Use this procedure for all eleven nylon rivets around the back panel assembly to secure it in place.
Insert and tighten the 2.9x6.5 self-tapping screw into the back panel.

Do not use excessive force when tightening this screw! If you encounter resistance, use a 2mm drill to pre-drill the hole. Or leave the screw not completely tightened.

STEP 36 Stepper splitter: parts preparation

Prepare

Stepper splitter x1

STEP 37 Guiding the Stepper splitter cable

Very carefully turn the assembly on its back (back panel).
It is recommended to support the rear of the assembly with a soft, raised pad to prevent it from resting on the protruding Wi-Fi module.
Guide the Stepper splitter cable through the three zip ties on the left side.
For now, leave the side with the label hanging freely outside.
Guide the Z-axis motor R cable through the three zip ties on the left side.

Tip: Use the foam padding from the sheet metal parts package or an empty cardboard box.

Do not tighten the zip ties at this moment.

STEP 38 Connecting the Stepper splitter

Connect the Z motor cables to the stepper splitter:
Stepper splitter cable Z-axis motor R Z-axis motor L Z-axis motor L

STEP 39 Mounting the Stepper Splitter

Locate two spacer pins in the bottom frame.
From the inside of the frame, prepare the Stepper splitter and attach its holes opposite the pins.
Check the correct orientation of the part by the logo on the board. The logo is upside down.
Push the aligned Stepper Splitter onto the pins until you feel a click - this secures the Stepper Splitter. Push in the center of the board.
It is necessary to apply a significant pressure to seat the part in. Yet, be very careful not to damage the components.

STEP 40 LCD cable: parts preparation

Prepare

xLCD cable x1

STEP 41 Guiding the LCD cable

Guide the Stepper splitter cable through the oval hole to the electronics.
Take the end of the xLCD cable with the QR code label.
Push a few centimeters of the xLCD cable (the end with the QR code label) through the oval hole in the bottom panel.
The cable must be slightly folded to pass through the hole.
Guide the xLCD cable through the zip ties on the left side of the frame.
Guide the xLCD cable through the rectangular opening in the front profile. Keep protruding approximately 6 cm (2.36 in).
Leave the cable hang freely for now.

STEP 42 Main FE cable INFO

Lay out the Main FE cable as shown in the picture, ensuring each connector is positioned accordingly.
The connectors are numbered in the picture for reference only. This numbering will be used in the following steps to help with proper connections.

Note: We will always indicate which connector to use in the following steps. However, it’s a good idea to remember this overview for easier assembly.

STEP 43 Connecting the FE cable (no 3.)

Prepare the connector number 3.
That's the female faston connector in the middle of the cable.
Locate the male Faston connector in the bottom right corner.
Slide the FE cable connector completely onto the Faston connector.

STEP 44 Guiding the FE cable (no. 2)

Take the FE cable connector number 2.
The round connector nearby.
Insert the connector loosely into the hole in the bottom panel.

STEP 45 Guiding the FE cable (no. 1)

Take the connector number 1 and guide it through the zip ties on the right side of the frame.
That is the long part with just one faston connector at the end.
Push the connector through the rectangular opening in the front profile. Keep protruding approximately 6 cm (2.36 in).
Leave the cable hang freely for now.
Tighten all three zip ties. Cut off the excess.

STEP 46 Guiding the FE cable (no. 4 and 5)

Take the FE cable connectors number 4 and 5.
Push both connectors through the leftmost hole in the bottom. Leave them free for now.
Tighten all three zip ties on the left side of the frame. Cut off the excess.
There’s no need to fully tighten the zip ties. However, the cables must still be easy to move for any necessary length adjustment during connection.
Carefully turn the printer back on its feet. Focus on the back side.

STEP 47 FE cable - xBuddy: parts preparation

Prepare

M3w washer x1M3x6 screw x1

STEP 48 Connecting the FE cable: xBuddy

Take the connector number 4 and connect it to the xBuddy using the M3x6 screw and M3w washer.
The M3 washer must be between the screw head and the connector.
Guide the FE cable (number 5) alongside the xBuddy box and pass it through the right-side holes out of the box.
Guide the Stepper splitter cable alongside the xBuddy box and connect it to the second slot from the right in the top row on the xBuddy board (labeled ZR).

STEP 49 Plugging the xLCD cable

Arrange the cables as shown - route all cables along the right side of the xBuddy box.
Place the xLCD cable over the other cables and route it upwards.
Connect the xLCD to the slot on the right side of the xBuddy. Note the safety latch on the xLCD cable connector. The latch must fit into the upper side of the connector.
Secure the cable arrangement by tightening the bottom zip tie.
Carefully cut off the excess length of the zip tie. Avoid cutting cables!

Make sure all the cables guide through the zip ties in the xBuddy box, not under them.

Do not tighten the three remaining zip ties!

Do not overtighten the zip tie, as it may damage the wires.

STEP 50 PSU-cover: parts preparation

Prepare

CORE-One-PSU-cover x1

STEP 51 Connecting the FE cable: PSU

Remove the screw from the PSU board. Do not discard it!
Insert the removed screw through the FE cable connector and screw it back to the PSU board.
Note the correct orientation of the connector.
Rotate the connector counter-clockwise, positioning it so it doesn't block the threaded hole underneath.
Attach the PSU-cover over the PSU connectors and secure with two M3x10 screws.

Ensure the FE connector (number 2) is routed into the PSU compartment.

STEP 52 Haribo time

Time to recharge for the next chapter!
Eat the second row.
No cheating—eat only the number shown!

STEP 53 Done

Congratulations! The back assembly is installed.
Now continue to the next chapter.

4Heatbed assembly difficulty◷ 1-1.5 hr40 stepsofficial ↗0/40›

STEP 1 Tools necessary for this chapter

Needle-nose pliers Universal wrench Wrench 13-16 Philips (PH2) screwdriver 2.5mm Allen key 2.0mm Allen key T10 torx key / T10 torx screwdriver

STEP 2 Heatbed: parts preparation

Prepare

Heatbed MK52 24V x1M3nN nut x2M3w washer x2

STEP 3 Heatbed cable assembly (part 1)

IT IS IMPORTANT to connect the power cable correctly. Before you start the assembly have a look at the pins. The one on the left with "GND" sign must be connected to the BLACK WIRE.
Take both Heatbed cables. Note the label on each cable. For the following steps, prepare the ends of the cables without the label.

STEP 4 Heatbed cable assembly (part 2)

Place the black wire above the pin with "GND" sign. Use the end of the cable that is not labeled with QR code. The QR code must be at the other end.
Note the correct position of the cable terminal lug on the detail.
Place the M3w washer above the round cable connector.
Push the M3x10rT screw through all parts.
Hold the screw and carefully turn the heatbed upside down.
Attach the M3nN nut onto the M3x10rT screw and tighten it slightly.
Using the same procedure, attach the red cable to the pin labeled "VCC" on the heatbed.
Guide the cables from the heatbed slightly towards each other (in a "V" shape).
Then tighten the nuts firmly from underneath.

STEP 5 Bed-cable-cover-bottom: parts preparation

Prepare

Bed-cable-cover-bottom x1M3n nut x3M3x10rT screw x1

STEP 6 Attaching the cable cover

Insert three M3n nuts into the Bed-cable-cover-bottom part.
Insert the Bed-cable-cover-bottom under the heatbed cables. Note the orientation of the part.
Slide the Bed-cable-cover-bottom under the cable joint of the heatbed.
Line up the hole in the heatbed with the cable cover and secure it with the M3x10rT screw.

Pro tip: Use the screw-pulling technique.

Make sure the nuts are fully inserted and held in place.

STEP 7 Heatbed carriage: parts preparation

Prepare

Heatbed carriage x1

The Fasteners package includes both M3x4r and M3x4rT screws. Make sure you have the correct type prepared.

STEP 8 Preparing the heatbed carriage

Place the heatbed carriage in front of you in the same orientation as in the picture.
Insert eight M3x4r screws around the heatbed carriage.

Make sure the rectangular cutout is facing you on the right side.

Ensure that you use the correct M3x4r screw for the Allen key. Do not use the torx screw, as the torx key will not fit through the hole in the joint.

Do not tighten completely; leave a gap of approximately 3 mm (0.12 in).

STEP 9 Installing the expansion joints

Attach one expansion joint to any M3x4r screw in the same orientation as shown.
Note the U-shaped "groove" for the screw inside the expansion joint - point it towards the screw.
Slide the expansion joint onto the screw.
Grasp the expansion joint in the rectangular cutout of the universal wrench.
Position the key with the expansion joint in its correct orientation as shown in the illustration.
Maintain the expansion joint in the correct position and firmly tighten the M3x4r screw through the expansion joint with a 2.0 mm Allen key.
Repeat this procedure for all other expansion joints. Follow their correct position!

STEP 10 RGB LED strip: parts preparation

Prepare

RGB LED strip 166 mm x1

LED status cover (1x) found in the Electronics & Chamber parts package in a bag labeled Others LED strip diffuser (1x) found in the CoreXY parts + Hinges set package Spacer 3.2/6x5 mm (2x) found in the Electronics & Fasteners package M3x10rT screw (2x)
Zip tie (3x)

Avoid direct contact with the LED and resistors on the LED strip.

STEP 11 Installing the LED strip

Place the heatbed carriage in front of you in the same orientation as in the picture.
Carefully peel off the protective (paper) layer from the RGB LED strip.
After removing the protective layer, the RGB LED strip is adhesive.
Stick the RGB LED strip evenly to the front of the heatbed carriage, approximately 3 mm (0.12 in) from the folded edge.
Align the middle LED with the screw on the carriage.
The RGB LED strip cable must point to the right.
After sticking, press lightly on the blank areas of the strip to ensure adhesion. Do not touch LEDs and resistors!

Make sure the rectangular cutout is far from you and on the right side.

STEP 12 Attaching the LED strip diffuser

Place the LED strip diffuser over the RGB LED strip. Note the orientation of the part - according to the beveled edges.
Place two spacers 3.2/6x5 mm on the holes in the edges of the LED assembly.

STEP 13 Covering the RGB LED strip

From both sides of the LED status cover, peel off the protective layers.
The other side of the cover is glossy.
Attach the LED strip cover to the assembly, matte side up.
Secure all parts together by inserting and tightening two M3x10rT screws. Do not overtighten the screws, as it may crack the cover.

Note that one side of the cover is matte.

STEP 14 Guiding the RGB LED strip cable

Thread the three zip ties along the RIGHT SIDE of the heatbed carriage. Make sure the zip tie heads are facing outward.
Guide the RGB LED strip cable through all zip ties.
Then tighten all three zip ties. Cut off excess zip ties.

STEP 15 Bed mounts: parts preparation

Prepare

CORE-One-bed-mount-left x1M3x10 screw x6M3n nut x2M3nN nut x10

STEP 16 Assembling the bed mounts

Place the CORE-One-bed-mount-left onto the bearing, ensuring the correct orientation.
Press the part onto the bearing, applying more force to ensure it moves all the way down. You will feel a click, indicating that the plastic part and bearing are correctly seated.
Use any flat screwdriver to carefully expand the opening in the bed mount if you struggle to insert the bearing.
The bearing must be fully enclosed within the part and must not protrude.
Follow the same procedure with CORE-One-bed-mount-right.

STEP 17 Securing the bed mounts

Insert one M3n nut into the CORE-One-bed-mount-left.
Position the CORE-One-bed-mount-left according to the picture:
Position the bearing so that two ball rows face the bottom of the part, not just one.
Keep the bearing in the position and secure it by inserting and tightening one M3x10 screw.
Follow the same procedure with CORE-One-bed-mount-right.

Ensure that the top surface of the bearing is flush with the top surface of the plastic part.

STEP 18 Bed mounts: inserting the nuts

Insert four M3nN nuts into both bed mounts.

Make sure they are inserted completely inside.

STEP 19 Assembling the CORE-One-bed-spacer-rear

Insert two M3nN nuts into the CORE-One-bed-spacer-rear.
Insert the nuts down as much as possible.

STEP 20 Installing the bed-mount-right

Turn the heatbed carriage piece with the "forks" facing you and with the expansion joints facing up.
Take the CORE-One-bed-mount-right part and slide it under the right fork - with the bearing on the right.
Fix it with two M3x10 screws.

STEP 21 Installing the bed-mount-left

Take the One-bed-mount-left part and slide it under the left fork - with the bearing on the left.
Fix it with two M3x10 screws.

STEP 22 Mounting the heatbed: parts preparation

Prepare

M3x12bT countersunk screw x1

Spacer 6x3.1x8 mm (1x) found in the Nextruder assembly package inside the Electronics box.
M3x4bT countersunk screw (8x)

Note: The package may label this screw as M3x12cT.

STEP 23 Mounting the heatbed

Place the spacer onto the heatbed carriage on the side with the expansion joints and align it with the hole in the center.
Put the heatbed on the heatbed carriage and secure it by the M3x12bT. Do not fully tighten the screw yet.
Insert the M3x4bT screws into the remaining holes in the heatbed. Do not fully tighten the screws yet.

Make sure the heatbed thermistor cable (the thinnest pair) is routed alongside the heatbed power cables. Do not route it around or across any expansion joints.

Ensure the correct orientation of the part. Use the heatbed cables as a guide.

STEP 24 Tightening the heatbed

IMPORTANT: The heatbed must be tightened in a specific order. Repeat the sequence multiple times, ensuring the final tightening after at least two rounds.
After all screws are in place, tighten them in the following sequence:
Center screw First four screws (edges)
Last four screws (corners)
Tighten the screws gently, but firmly.

STEP 25 Covering the cables: parts preparation

Prepare

CORE-One-bed-cable-cover-top x1Textile sleeve 520 x 8 mm x1

STEP 26 Guiding the heatbed cables

Pull the RGB LED strip cable from the bottom through the rectangular cutout to the top.
Guide the heatbed thermistor cable under the RGB LED cable, and insert the heatbed thermistor cable into the cable channel in the cable cover.
Route the RGB LED strip cable through the cable channel.
Guide the heatbed power cables through the cable channel.

STEP 27 Covering the heatbed cables

Thread approximately 5 cm (2 in) of the textile sleeve onto the heatbed cable bundle and slide the textile sleeve 1 cm (0.39 in) into the cable channel.
Attach the CORE-One-bed-cable-cover-top on the heatbed cables.
Secure the top cover with two M3x10 screws.
Wrap the rest of the textile sleeve around the cable bundle.

Make sure the textile sleeve is still in place - inside the cable cover. Do not pull on the textile sleeve.

STEP 28 Mounting the heatbed: parts preparation

Prepare

Trapezoidal nut x3

Two trapezoidal nuts are included in the motors set package, and one nut can be found in the Electronics & Chamber parts package.
M3x18 screw (6x)

STEP 29 Attaching the heatbed assembly

Take the back and base assembly and orient the front side towards you.
Place the CORE-One-bed-spacer-rear onto the rear motor screw heads, making sure it stays in place.
Note the orientation of the part and holes as shown. The holes must be parallel to the motor screw heads.
Very carefully thread the heatbed assembly onto the threaded rods of the Z motors, then gently lay it down onto the base. Make sure that the spacer at the bottom does not move.
The heatbed cable must run under the heatbed and behind the rear motor.

Ensure that the heatbed cable does not touch the spacer and remove it from the motor.

STEP 30 Mounting the heatbed assembly: rear motor

Double-check that the heatbed cable bundle (textile sleeve) runs properly—it must go under the heatbed assembly and behind the threaded rod of the rear motor.
Manually thread the trapezoidal nut onto the rear Z motor. Screw the nut all the way down until it seats into the heatbed carriage.
Align the holes in the trapezoidal nut, carriage and bed-spacer-rear.
It doesn’t matter which holes you use in the trapezoidal nut.
Secure the trapezoidal nut, heatbed carriage and bed-spacer-rear together with two M3x18 screws.

Ensure the heatbed assembly is seated correctly—all threaded rods pass through the correct holes.

Ensure the correct orientation of the part. The protruding section must face downwards.

Tip: You can push a 1.5 mm Allen key through the holes in all the parts to align them.

STEP 31 Mounting the heatbed assembly: front motor left

Manually thread the trapezoidal nut onto the left Z motor. Screw the nut all the way down until it seats into the plastic part.
Align the holes in the trapezoidal nut with those in the plastic part. Either pair of holes can be used.
Secure all the parts together with two M3x18 screws.
Once the screws are tightened, loosen them by a quarter turn to provide a small amount of leeway.

Ensure the correct orientation of the part. The protruding section must face downwards.

STEP 32 Mounting the heatbed assembly: front motor right

Manually thread the trapezoidal nut onto the right Z motor. Screw the nut all the way down until it seats into the plastic part.
Align the holes in the trapezoidal nut with those in the plastic part. Either pair of holes can be used.
Secure all the part together with two M3x18 screws.

Ensure the correct orientation of the part. The protruding section must face downwards.

STEP 33 Attaching the heatbed cables I.

Locate the grommet hole at the top right of the rear assembly and push the heatbed cables through in the following order:
Guide the RGB LED strip cable through the hole first.
Route the thermistor cable through the hole.
Finally, insert both power cables of the hole.

STEP 34 Attaching the heatbed cables II.

Push the heatbed cables and the textile sleeve through the grommet hole.
No more than 1 cm (0.39 in) of the textile sleeve should protrude from the back side.

STEP 35 Securing the heatbed cables: parts preparation

Prepare

Zip tie x1Power terminal screw 6-32 x2

STEP 36 Securing the textile sleeve

Guide the zip tie through the two holes under the heatbed cables and make a loop around the heatbed cable bundle (textile sleeve) on the inside.
Tighten the zip tie firmly and cut off the excess.

STEP 37 Guiding the heatbed assembly cables

Route the RGB LED strip cable through the left hole in the xBuddy box and connect it to the xBuddy Extension board labeled ‘RGBW LED.’ Connect it to the first slot from the right on the xBuddy extension board.
Guide the heatbed power cables along with the thermistor through the left hole.
Leave the cables hanging freely for now.

STEP 38 Connecting the heatbed power cables

Using the 6/32" terminal screw connect the black power cable to the left terminal slot on the xBuddy board. Tighten firmly.
Using the 6/32" terminal screw to connect the red power cable to the right terminal slot. Tighten firmly.
Plug the heatbed thermistor connector to the slot next to the power terminals.

Ensure that none of the heatbed cables run over the zip ties—they must be guided underneath.

STEP 39 Haribo time

Time for another quick energy boost!
Eat the third row.
With one extra treat. You deserve it!

STEP 40 Done

Congratulations! You have just assembled and installed the heatbed.
Let's go to the next chapter.

5CoreXY assembly difficulty◷ 2-3.5 hr83 stepsofficial ↗0/83›

STEP 1 Tools necessary for this chapter

Needle-nose pliers 2.0mm Allen key 2.5mm Allen key T10 torx key / T10 torxy screwdriver

STEP 2 Rod holders: parts preparation

Prepare

Rod holder left x1M3x6 screw x4CoreXY plate x1

STEP 3 Assembling the rod holders

Insert two M3x10 screws into the Rod holder left and two into the Rod holder right.
Insert one M3x10 screw into each Rod holder rear. Insert from the side with the screw head hole.

Do not tighten them completely, a few turns are enough for now.

STEP 4 Preparing the front rod holders

Place the CoreXY plate as shown - the bent parts of the plate must point upwards.
Divide the Rod holder left and the Rod holder right into the sides of the front:
Rod holder left Rod holder right

Ensure you are preparing the correct part for the correct side. Use the chamfers on both parts as a reference for alignment.

STEP 5 Installing the front rod holders

Place the Rod holder left to the left front corner on the corresponding threaded holes.
Secure it with two M3x6 screws.
Place the Rod holder right to the right front corner on the corresponding threaded holes.
Secure it with two M3x6 screws.

STEP 6 XY carriage: parts preparation

Prepare

Linear holder left x1LM10LUU linear bearing x2M3x18 screw x10

STEP 7 Assembling the XY-carriages

Take one of the XY-carriage and orient it as shown. Use the beveled side as a guide.
Insert the GT2-20 Idler pulley into the XY-carriage.
Push one M3x18 screw through the pulley and tighten it completely down.
Turn the part upside down.
Insert another GT2-20 Idler pulley into the XY-carriage.
Secure it with the M3x18 screw. Tighten it completely down.
Repeat the same procedure with the second XY-carriage.

STEP 8 Assembling the linear holder left

Prepare the Linear holder left and position it as in the picture.
Attach one of the XY-carriages to the Linear holder.
Install it to the Linear holder with three M3x18 screws.
Turn the Linear holder upside down.
From the XY-carriage side, attach the LM10LUU linear bearing to the holder and secure it with four M3x8rT screws.

STEP 9 Assembling the linear holder right

Prepare the Linear holder right and position it as in the picture.
Attach one of the XY-carriages to the Linear holder.
Install it to the Linear holder with three M3x18 screws.
Turn the Linear holder upside down.
From the XY-carriage side, attach the LM10LUU linear bearing to the holder and secure it with four M3x8rT screws.

STEP 10 Attaching the linear holder assemblies

Position the CoreXY plate as shown in the picture, ensuring the front rod holders are facing up.
Slightly lift the CoreXY plate and from the plate's inner side loosely attach the Linear holder of the assemblies.
Linear holder left Linear holder right The linear holders are now only loosely seated.

STEP 11 Smooth rods INFO

Prepare

M3x6 screw x4

There are two different types of smooth rods in the package. Compare carefully with the picture and prepare the correct ones required.
Smooth rods are included in the Rods box.
Smooth rod 330 x 8 mm (2x)
Smooth rod 325 x 10 mm (2x) required for the following steps

STEP 12 Mounting the smooth rods

Slide both rear rod holders onto both 10mm smooth rods.
Line up the ends of the rods with the holders.
Push both 10mm smooth rods through the LM10LUU bearing to the front rod holders.
Line up the front end of the 10mm smooth rods with the front rod holders.

Make sure the screws on the rear rod holders are pointing out of the frame.

STEP 13 Securing the rear rod holders

Line up the left rear rod holder with the threaded holes in the plate.
Fix it with two M3x6 screws.
Firmly tighten the screw in the rod holder.
Line up the right rear rod holder with the threaded holes in the plate.
Fix it with two M3x6 screws.
Firmly tighten the screw in the rod holder.

STEP 14 Securing the front rod holders

Focus on the front left holder (currently on the right) and secure the rod by tightening the screw in the holder.
Focus on the front right holder (currently on the left) and secure the rod by tightening the screw in the holder.

Do not tighten the bottom screw.

STEP 15 Motor mounts: parts preparation

Prepare

XY-motor-mount-left x1M3x18 screw x2Spacer 3.2/6x2 x2M3nS nut x1

The list continues in the next step...

STEP 16 Motor mounts: part preparation

GT2-20 Idler pulley (6x) found in the Electronics & Fasteners package

STEP 17 Assembling the XY-motor-mount-right I.

Insert one pulley into the lower position in the Assembly-multi-tool.
Insert the spacer 3.2 on the pulley.
Insert the second pulley into the Assembly-multi-tool.
Insert the whole assembly into the XY-motor-mount-right as shown. Note the beveled corner.

STEP 18 Assembling the XY-motor-mount-right II.

Align the holes in both parts and insert the M3x30 screw. Slowly and carefully tighten the screw.
The plastic part has no pre-cut thread, so the screw will create it as you tighten.
Slight resistance is expected.
Stop tightening once the M3x30 screw head reaches the XY-motor-mount. Do not overtighten the screw!
Remove the Assembly-multi-tool.
Insert another pulley into the XY-motor-mount-right.
Secure it with M3x18 screw. Do not overtighten the screw.
Insert the M3nS nut into the XY-motor-mount-right.

STEP 19 Assembling the XY-motor-mount-left I.

Insert one pulley into the lower position in the Assembly-multi-tool.
Insert the spacer 3.2 on the pulley.
Insert the second pulley into the Assembly-multi-tool.
Insert the whole assembly into the XY-motor-mount-left.
Position the part according to the picture. Note the bevel next to the screw hole.

STEP 20 Assembling the XY-motor-mount-left II.

Align the holes in both parts and insert the M3x30 screw. Slowly and carefully tighten the screw.
The plastic part has no pre-cut thread, so the screw will create it as you tighten.
Slight resistance is expected.
Stop tightening once the M3x30 screw head reaches the XY-motor-mount. Do not overtighten the screw!
Remove the Assembly-multi-tool.
Insert another pulley into the part.
Secure it with M3x18 screw. Do not overtighten the screw.

STEP 21 Belt tensioners: parts preparation I.

Prepare

GT2-20 Idler pulley x2M3x18 screw x2M3x12 screw x1M3nS nut x2

The list continues in the next step...

STEP 22 Belt tensioners: parts preparation II.

Prepare

Belt-tensioner-left x1

STEP 23 Preparing the tensioner pulleys

Insert one M3nS nut into each Belt- tensioner-pulley.
Keep both parts in this position.

Make sure the nuts are correctly inserted into the parts. The holes in the nuts and the parts must be aligned.

STEP 24 Assembling the belt tensioner left I.

Apply a small amount of Prusa lubricant to the tip of both M3x30 screws.
Spread the lubricant evenly around the entire thread.
Slide the Belt-tensioner-left onto the Belt-tensioner-pulley.
Insert the M3x30 screw through the Belt-tensioner-left into the Belt-tensioner- pulley. Do not tighten completely! 3-4 turns are sufficient.

Tip: Use the tip of a zip tie to spread the lubricant.

Ensure the parts are oriented correctly, as shown.

STEP 25 Assembling the belt tensioner left II.

Insert the GT2-20 Idler pulley into the Belt-tensioner-pulley.
Secure it with the M3x18 screw.
The plastic part has no pre-cut thread, so the screw will create it as you tighten.
Slight resistance is expected.
Insert the M3x12 screw into the Belt-tensioner-left. Tighten slightly—five turns are enough. It must not protrude through the other side.

Note: This screw, referred to as the tensioning screw, will later be used to adjust the door sensor.

STEP 26 Assembling the belt tensioner right

Slide the Belt-tensioner-right onto the Belt-tensioner-pulley.
Insert the M3x30 screw through the Belt-tensioner-right into the Belt-tensioner- pulley. Do not tighten completely! 3-4 turns are sufficient.
Insert the GT2-20 Idler pulley pulley into the Belt-tensioner-pulley-right.
Secure it with the M3x18 screw.
The plastic part has no pre-cut thread, so the screw will create it as you tighten.
Slight resistance is expected.

Ensure the parts are oriented correctly, as shown.

STEP 27 Installing the belt tensioners: parts preparation

Prepare

M3x30 screw x5M3x18 screw x1M3x6 screw x2Belt tensioner left assembly x1

STEP 28 Installing the motor mount left

Locate the corner of the CoreXY plate with the Faston connector on it. It is on the underside of the assembly.
Position the motor-mount-left on the CoreXY plate as shown in the picture.
Note the rectangular protrusion on the motor-mount-left and the rectangular cutout on the CoreXY plate.
Slide the motor-mount-left under the CoreXY plate, ensuring the rectangular protrusion fits into the cutout.
Align the holes in both parts and secure them with an M3x6 screw in the designated hole

STEP 29 Installing the motor mount right

Position the motor-mount-right on the CoreXY plate as shown in the picture.
Note the rectangular protrusion on the motor-mount-right and the rectangular cutout on the CoreXY plate.
Slide the motor-mount-right under the CoreXY plate, ensuring the rectangular protrusion fits into the cutout.
Align the holes in both parts and secure them with an M3x6 screw in the designated hole

STEP 30 Installing the belt-tensioner-left

Turn the CoreXY assembly upside down so that the bent parts face downward.
Focus on the front left corner on the assembly.
Place the belt-tensioner-left assembly in the front left corner of the CoreXY plate.
Align it with the front and inner side edges.
Line up the holes in both parts.
Secure the part with two M3x30 screws.
Insert and tighten one M3x18 screw.

STEP 31 Installing the belt-tensioner-right

Place the belt-tensioner-right assembly in the front right corner. Align it with the front and inner side edges.
Line up the holes in both parts.
Secure the part with three M3x30 screws.

STEP 32 Linear rail: parts preparation

Prepare

M3x6 screw x6Linear rail beam x1

Piece of cloth or a paper towels to wipe the preservative lubricant from the linear guide.

STEP 33 Attaching the linear rail

Under no circumstances remove the anti-ejection safety pins. Wait for the prompt in the instructions.
Immediately after removing the linear guide from the package, wipe off the preservative lubricant with a paper towel.
Place the linear rail on the linear rail beam and line up the holes in both parts.
Move the linear carriage approximately to the center of the rail.
Insert and slightly tighten two M3x6 screws into the third holes from both ends.

STEP 34 Securing the linear rail

Relocate the safety pins from each end to the fourth holes from the ends of the linear rail.
Gently squeeze the safety pin with needle-nose pliers and pull it out.
Insert two M3x6 screws into the fifth holes from the ends of the rail. Tighten just slightly.
Insert two M3x6 screws into the first holes in the rail. Tighten just slightly.

Do not move the linear carriage in any way in this step.

Do not remove the safety pins from the rail.

STEP 35 Installing the linear rail: parts preparation

Prepare

M3x8rT screw x6

There are both M3x8rT and M3x8 screws in the kit. Make sure you have prepared the correct ones.
Linear rail assembly (1x) you assembled earlier

Do not remove the safety pins.

STEP 36 Installing the linear rail assembly

Position the assembly with the motor mounts facing you.
Move both linear holders approximately to the center of the Y-axis.
Attach the linear rail assembly to the holders from the front side of the assembly.
Secure it with three M3x8rT screws from the back side on both the left and right sides.

STEP 37 Linear rail: removing the safety pins

Gently squeeze both safety pins with needle-nose pliers and pull them out of the linear rail.
You can discard the safety pins as they are no longer needed.

STEP 38 Bed-stop: parts preparation

Prepare

Bed-stop-rear x1M3x8rT screw x3

STEP 39 Assembling the bed-stop

Insert two M3nS nuts into the bed-stop from one side.
Insert one M3nS nut into the bed-stop from the other side.

STEP 40 Mounting the bed-stop

Position the CoreXY assembly as shown, ensuring the motor mounts face upwards.
Focus on the triangle protrusion on the metal part.
Insert the bed-stop-rear under the protrusion at the back of the CoreXY plate.
Align all three holes in both parts.
Secure both parts together with three M3x8rT screws.
The upper screw is screwed into plastic with no pre-cut thread. It cuts the thread as it's tightened. Slight resistance is expected.

STEP 41 X&Y motors: parts preparation

Prepare

Y-axis motor x1

Pulley T16-2GT (2x) found in the Electronics package (the bag may be labeled GT2-16)
Assembly-multi-tool (1x) you already used

Note that the motors are marked as X and Y-axes in order to distinguish between them. We will continue to follow this marking.

STEP 42 Installing the X-axis pulley

Prepare the X-axis motor.
Note the flat part on the motor shaft.
Slide the Pulley on, note the CORRECT orientation.
Rotate the motor shaft with the flat part facing you.
Using the fork on the Assembly-multi-tool set a gap between the pulley and the motor.
Push the pulley on the tool and firmly tighten the screw against the flat part on the shaft.
Rotate the pulley and firmly tighten the second grub screw.
Double-check the pulley orientation. The toothed side of the pulley must be on the motor side.

STEP 43 Installing the Y-axis pulley

Prepare the Y-axis motor.
Note the flat part on the motor shaft. Rotate the motor shaft with the flat part facing you.
Slide the Pulley on, and note the CORRECT orientation. The Y-axis pulley orientation is DIFFERENT from the X-axis. Make sure the pulley teeth face away from the motor. Use the wider hook on the assembly tool.
Using the hook on the Assembly-multi-tool, place the thicker curved part between the pulley and the motor.
Push the pulley on the tool and firmly tighten the screw against the flat part on the shaft.
Rotate the pulley and firmly tighten the second grub screw.
Double-check the pulley orientation. The teeth must face away from the motor.

Do not try to hook it around the shaft. Just rest the tool against the motor and make sure the hook tip slides between the motor and the pulley.

STEP 44 XY belts: parts preparation

Prepare

X-axis motor assembly x1

STEP 45 XY belts INFO

The next steps cover belt installation and guiding on the core XY assembly. Before starting, refer to the illustration for an overview and better understanding of each belt’s path.
X-axis belt - at the top position Y-axis belt - at the bottom position Let's guide the belts step by step...

STEP 46 Y belt guiding: Y motor pulley

From the back of the CoreXY, focus on the motor-mount on the left side.
Create a loop anywhere on the belt so the belt teeth are pointing inside the loop.
Push this loop through the space between the lower pulleys inside the motor mount.
Push through enough to make the loop follow the top round hole of the motor- mount as closely as possible.
Insert the Y motor into the motor holder, the pulley must be in the middle of the belt loop.
Insert the Y motor pulley into the motor mount, ensuring the pulley is centered within the belt loop.
Fully attach the motor to the motor-mount with the motor cable facing you.
Pull lightly on the belt loop to encircle the pulley.

STEP 47 Securing the Y-axis motor

Firmly grasp the Y-axis motor assembly and position the CoreXY assembly vertically. Do not drop the motor!
Keep holding the motor with one hand. With the other hand, secure the motor using four M3x35 screws on the underside of the frame. Tighten firmly.
Place the CoreXY assembly back into the horizontal position.

Be careful not to pull the entire belt out of the motor.

STEP 48 Y belt guiding: Y motor mount

Guide the left end of the belt around the lower left pulley.
Push the belt through the part and guide it to the front of the CoreXY plate.
Don't pull too long so you don't pull the whole belt out. Remember that the other end is loose. The whole process would then have to be repeated.

STEP 49 Y belt guiding: belt tensioner

Guide the belt around the pulley in the belt tensioner.
Push the belt around the front pulley in the linear assembly.
Prepare the Nextruder holder in the same orientation as in the picture. Note the holes for securing the belts.
Push the end of the belt through the middle hole into the left hole in the bottom row - leave 4-5 teeth sticking out.
The belt is secured on this end. You can leave it free for now.
If it is difficult to reach the Nextruder holder with the belt, try temporarily loosening the belt tensioner screw on the front of the assembly.

STEP 50 Y belt guiding: X motor mount

Back to the other end of the Y belt.
Take the other end of the belt and guide it around the lower pulley in the X motor mount.
Push it through the motor mount to the front.
Route the belt around the lower right pulley in the linear rail holder.

STEP 51 Y belt guiding: securing the belt

Push the end of the belt through the middle hole to the right hole in the bottom row of the Nextruder holder - leave 4-5 teeth sticking out.
If it is difficult to reach the Nextruder holder with the belt, try loosening the belt tensioner screw on the front of the assembly.
Don’t forget to adjust it back after securing the belt.

STEP 52 X belt guiding: X motor pulley

From the back of the CoreXY, focus on the motor-mount on the right side.
Create a loop anywhere on the second belt so the belt teeth are pointing inside the loop.
Push this loop through the space between the upper pulleys inside the motor mount.
Push through enough to make the loop follow the top round hole of the motor- mount as closely as possible.
Insert the X motor pulley into the motor mount, ensuring the pulley is centered within the belt loop.
Pull lightly on the belt loop to encircle the pulley.

Ensure the motor cable is facing you (rear).

STEP 53 Securing the X-axis motor

Firmly grasp the X-axis motor assembly and position the CoreXY assembly vertically. Do not drop the motor!
Keep holding the motor with one hand. With the other hand, secure the motor using four M3x35 screws on the underside of the frame. Tighten firmly.
Place the CoreXY assembly back into the horizontal position.

Be careful not to pull the entire belt out of the motor.

STEP 54 Y belt guiding: X motor mount

Guide the right end of the belt around the upper right pulley.
Push the belt through the part and guide it to the front of the CoreXY plate.
Don't pull too long so you don't pull the whole belt out. Remember that the other end is loose. The whole process would then have to be repeated.

STEP 55 X belt guiding: belt tensioner

Guide the belt around the pulley in the belt tensioner.
Push the belt around the front upper pulley in the linear assembly.
Route the end of the belt through the middle hole into the right hole - leave 4-5 teeth sticking out.
The belt is secured on this end. You can leave it free for now.

STEP 56 X belt guiding: Y motor mount

Back to the other end of the X belt.
Take the other end of the belt and guide it around the upper pulley in the Y motor mount.
Push the belt through the motor mount.
Route the belt around the upper front pulley in the linear rail holder.

STEP 57 X belt guiding: securing the belt

Push the end of the belt through the middle hole to the left hole in the upper row of the Nextruder holder - leave 4-5 teeth sticking out.

STEP 58 Checking the belt guidance

Before proceeding, recheck the belt routing according to the illustration.

STEP 59 Bowden guide: parts preparation

Prepare

Bowden-guide x1M3nS nut x1Zip tie x2

STEP 60 Securing the Nextruder holder

Attach the Nextruder holder to the linear rail carriage and secure it using four M3x10 screws.
CAUTION: Ensure no belt obstructs the screw. Avoid screwing through the belt!

STEP 61 Securing the Y motor cable

Push the zip tie through the motor-mount-right.
Route the Y motor cable through the cable channel in the motor-mount-right and over the zip tie.
Secure the cable with a zip tie and trim the excess.

STEP 62 Securing the X motor cable

Push the zip tie through the motor-mount-left.
Route the X motor cable through the cable guide in the motor-mount-left and over the zip tie.
Secure the cable with a zip tie and trim the excess.

STEP 63 Installing the bowden guide

Insert the M3nS nut into the motor-mount-right.
Attach the bowden-guide to the motor-mount-right.
Note the correct orientation of the part.
Fix the bowden-guide in place using the M3x10 screw.

STEP 64 White LED strip: parts preparation

Prepare

White LED strip x1M3x4rT screw x2

STEP 65 Sticking the White LED strip

Carefully peel off the protective (paper) layer from the White LED strip.
After removing the protective layer, the LED strip is adhesive.
Position the White LED strip near the CoreXY strut to check alignment, but do not attach it yet.
Note the rectangular cutout on the strut, orient the strip cable to the same side.
Stick the White LED strip evenly to the strut - on the side with the rectangular cutout.
After sticking, press lightly on the blank areas of the strip to ensure adhesion. Do not touch LEDs and resistors!

STEP 66 Installing the white LED assembly

Take the white LED assembly and attach it to the front of the CoreXY assembly.
Align the holes of both parts.
The white LED strip cable must point to the left.
Attach the LED assembly to the CoreXY plate and secure it with two M3x4rT screws.

STEP 67 Door sensor & White LED strip: parts preparation

Prepare

Door sensor x1M2.5x10 screw x1

STEP 68 Inserting the zip ties

Flip the CoreXY assembly upside down and rest it on the motors.
Position it with the white LED strip cable facing toward you.
Thread three zip ties through the CoreXY plate, ensuring the zip tie heads point inward. Make sure that the zip ties do not catch the belts from the other side.
Partially tighten the zip ties—just enough to catch the first few teeth.
Flip the assembly back with the motors facing upwards.

Do not fully secure them yet, as we will route cables through them later.

STEP 69 Installing the door sensor

Place the door sensor on the left belt tensioner. The lever of the door sensor must face forward.
Secure the door sensor with the M2.5x10 screw.
Tighten the bolt fully and then loosen 1/4 turn. The sensor must be allowed to move.
From the rear of the belt tensioner, tighten the M3x12 screw so that it touches the door sensor.

STEP 70 Securing the door sensor cable

Push the zip tie through the hole in the left belt tensioner.
Guide the door sensor cable through the zip tie.
Tighten the zip tie to secure the door sensor cable. Cut off the excess.

STEP 71 Guiding the cables: LED and door sensor

Prepare a cardboard box. You can use any box from the kit. The box used in the picture is for illustrative purposes only.
Flip the CoreXY assembly upside down, positioning the smooth rods on top.
Slightly lift and support the front side of the CoreXY assembly with the cardboard box.
Route the white LED strip cable and the door sensor cable through the zip ties.
Tighten all the zip ties to secure the cables. Cut off the excess zip ties.
If you plan on adding the Buddy camera, do not tighten the zip ties all the way. As you will be adding another USB-C cable to the zip ties soon.
Cables must be slightly taut and straight. Excess slack or bends may cause collisions with the Y-axis and lead to damage.

Be careful not to damage the door sensor.

STEP 72 Buddy3D Camera Note

For future Buddy3D Camera users only. Skip this step if you are not planning to install the Buddy3D Camera.
Disclaimer: Typically, the printer must be fully assembled and tested before any add-ons can be installed. Choosing to install the Buddy3D Camera USB cable now will save you time later on.
For detailed information on cable placement, refer to the separate guide Buddy3D Camera for CORE One Installation The above-mentioned guide on how to install the Buddy3D Camera shows the printer in a further stage of assembly.
For now, use the guide to make sure that the cable is installed correctly and tighten the zipties.
We will let you know later on when to return to the guide and finish the Buddy camera installation.

STEP 73 Smooth rods: parts preparation

Prepare

Smooth rod 330 x 8 mm x2

STEP 74 Installing the CoreXY assembly

Carefully insert both smooth rods through the heatbed assembly bearings and into the rod mount part in the base assembly.
It is a requirement to insert the smooth rod in the axis with the bearing very slowly to prevent the balls from shooting out of the bearing.
Temporarily hang the cables from the cooling fans over the rear panel. There must be a space between the cables and the back panel pocket.
Exercise extreme caution when placing the assembly on the smooth rods and back panel assembly.
The threaded rod of the rear Z motor must pass through the bed-stop-rear part.
Always lift it by the base of the entire assembly.

Ensure that no cables are pinched.

Ensure both smooth rods are properly seated in the rod holders.

WARNING: When handling the printer, DO NOT lift it by the CoreXY assembly.

STEP 75 Securing the smooth rods

Check that both smooth rods are seated correctly in the holders. The smooth rods have to be inserted into the holder all the way.
If you are not sure, you can gently and carefully insert a flat screwdriver into the slit and widen it to ensure that the rods are in all the way.
Firmly tighten the right M3x10 screw to secure the smooth rod.
Firmly tighten the left M3x10 screw to secure the smooth rod.

STEP 76 Aligning the linear rail

Move the linear rail carriage to the center.
Firmly tighten all screws in the order shown in the picture.
Push the linear rail down while tightening.

STEP 77 Guiding the corexy cables

From the back of the printer, push the FE connector through the oval hole.
Locate the FE cable connector (number 5) in the rear left corner - under the CoreXY assembly.
Plug the FE connector onto the Faston on the underside of the CoreXY plate.
On the same side, push the X motor cable through the oval hole in the back panel.
Push the White LED strip and Door sensor cables through the oval hole in the back panel.

STEP 78 Guiding the cooling fan cables

Push the cooling fan and thermistor cables through the oval hole in the back panel.
On the right back corner, locate the Y motor cable and push it through the upper oval hole in the back panel.

STEP 79 Fixing the bed-stop

From the back side, locate the oval screw hole under the cooling fans.
The oval hole must be flush with the hole in the bed-stop part on the opposite side.
To compensate, slightly raise the rear of the CoreXY assembly - just a few millimeters.
After aligning the holes, secure them with an M3x8rT screw.

STEP 80 Connecting the cooling fans cables

Route the cooling fan cables through the left hole in the xBuddy box and plug them into the fourth and fifth slots on the xBuddy extension board labeled FAN 1 and FAN 2.
The connection order does not matter, both cables are the same.
Guide the chamber thermistor cable together with the cooling fan cables.
Connect it to the second slot from the left on the xBuddy extension board labeled TEMP.

STEP 81 Connecting the corexy cables

Guide the X motor cable through the right hole in the xBuddy box. Connect it to the first slot from the left on the xBuddy board.
Guide the door sensor cable through the right hole in the xBuddy box. Connect it to the lower slot on the left side of the xBuddy board.
Guide the white LED strip cable through the right hole in the xBuddy box. Connect it to the second slot from the right on the xBuddy extension board.
Guide the Y motor cable through the left hole in the xBuddy box. Connect it to the second slot from the left on the xBuddy board.

STEP 82 Haribo time

You deserve to eat the whole bag, but please practice restraint. Eat just the fourth row.

STEP 83 Done

Congratulations! You have just assembled and installed the CoreXY assembly.
Let's go to the next chapter.

6Nextruder assembly difficulty◷ 2.5-4 hr58 stepsofficial ↗0/58›

STEP 1 Tool necessary for this chapter

Universal wrench 1.5mm Allen key 2.5mm Allen key T6 torx key T10 torx key / T10 torx screwdriver

STEP 2 Nextruder idler assembly: parts preparation

Prepare

Idler-lever-a x1Idler-lever-b x1Bearing 693 2RS x2Tubular spacer 13.2x3.8x0.35 x1

STEP 3 Assembling the extruder idler

Place both bearings into the Idler-lever-a.
Insert the pin 2.9x8.5 into each bearing 693 2RS, as seen in the picture.
Close it up with the Idler-lever-b part and secure it with the M3x6 screw. Do not overtighten the screw. Both bearings must be able to rotate without significant resistance.
From the same side, push the tubular spacer into the assembly. The "bottom" of the tubular spacer must be flush with the bottom part of the Idler assembly.

STEP 4 Assembling the extruder: parts preparation I.

Prepare

PG-assembly x1

STEP 5 Assembling the extruder: parts preparation II.

Extruder motor (1x) found in the Motors package Spacer 5x10x0.1 mm (1x) found in the Nextruder bag located in the Electronics package Socket set screw M3x25 (1x) found in the Electronics & Fasteners package

STEP 6 Assembling the extruder

Place the 5x10x0.1 spacer over the shaft on the extruder motor.
Place the heatsink on the extruder motor. Note the orientation of both parts.
The motor cable must be facing "up".
The heatsink cables must be on the right side.
Double-check that the motor cable and the heatsink cables are oriented as shown in the photo!
Place the main-plate on the heatsink. Note the orientation of the part. Use the cutout as a guide.
Before proceeding to the next step, make sure that the 5x10x0.1 spacer is placed on the extruder motor.

STEP 7 Assembling the gearbox

The following instructions need to be done correctly and carefully. Achieve better understanding and successful assembly by watching the video alongside the guide:
prusa.io/PG-assembly After watching the video, follow the steps in this guide.
Attach the PG-assembly-adapter on the PG-assembly. Note the pockets for the gears in the adapter.

STEP 8 Assembling the PG-ring

Slide the PG-ring onto the adapter.
Note there is a chamfer on one side of the PG-ring teeth. This side must be facing down (to the PG-assembly).
Grasp the entire assembly in one hand so that it can be rotated with the PG-ring.
With the other hand, slide the PG-ring onto the PG assembly in a wobbling motion (move the PG-ring left and right repeatedly) - a quarter turn is enough.
Stop when the surfaces of the gears are approximately flush with the surface of the PG ring.

Do not assemble the gearbox without the PG-assembly-adapter. This tool is intended to ensure that the gears are correctly fit together.

STEP 9 Assembling the PG-assembly

Proceed very carefully in this step.
Maintain the position of the PG-assembly and attach it on to extruder motor shaft.
Very gently and freely rotate with the whole PG assembly (PG-assembly-adapter, PG-assembly and PG-ring) until it drops down so that there is no gap between the assembly and the main-plate. Do not push on the assembly.
Remove the PG-assembly-adapter.

STEP 10 Checking the PG-assembly

Attach the PG-assembly-adapter back on the PG-assembly again to verify that all parts are properly seated.
Rotate with the PG-assembly-adapter. The PG assembly must be easy to rotate without having to exert much force.
Remove the PG-adapter. You will no longer need it during assembly. We recommend keeping it for maintenance.

Ensure that the PG-assembly is not sticking out above the PG-ring. It should be positioned lower than the level of the PG-ring's surface or at the same level as the ring.

Ensure that the gap between the PG-ring and the Main-plate is minimal. If a significant gap is observed, disassemble the planetary gear assembly and reposition it.

STEP 11 Assembling the Nextruder idler

Insert the idler assembly between the PG-ring and the extruder motor. There is a cutout for the spacer in the main-plate. Line up the idler spacer with the hole in the PG-ring.
Secure both parts with the socket set screw 3x25. Do not overtighten the screw!
The screw protrudes from the PG-ring after tightening.

STEP 12 Gear lubrication: parts preparation

Prepare

Front Case x1M3x25 screw x3Lubricant x1

STEP 13 Lubricating the gear

Remove the cap from the lube. Use the spike on the opposite side of the cap to pierce a hole in the lube tube opening.
Squeeze a small amount of lubricant onto the tip of the zip tie, then spread it over the gears.
Apply a small amount of Prusa Lubricant all around the PG-ring and PG-assembly teeth.
Close the lubricant; it is no longer needed for the assembly.

STEP 14 Covering the planetary gear

Using the paper towel, wipe off the lubricant residue from the face surface of the PG-ring.
Place the front case onto the gearbox and secure it with three M3x25 screws. Do not tighten them completely at this moment.
The screws on the front case will be completely tightened during the self-test in the final chapter.

STEP 15 Assembling the Idler-swivel: parts preparation

Prepare

Idler-swivel x2M3x20rT screw x2M3nN nut x2Spring 15x5 x2

STEP 16 Assembling the Idler-swivel

Push the M3x20rT screw all the way through one of the idler-swivel.
Slide the spacer onto the screw.
Place the second idler-swivel from the opposite side on the screw.
From the other side, attach the M3nN nut onto the screw. Hold the nut using the universal wrench and tighten the screw. Tighten just lightly! The spacer must rotate freely.

STEP 17 Assembling the Idler-nut

Insert the Idler-nut into the Idler-swivel assembly. Make sure that both parts are oriented correctly according to the picture.
Secure both parts together by inserting the M3x20rT screw from the same side, like the first screw.
Secure the screw with M3nN nut. Do not overtighten the nut. It must be possible to move with the Idler-swivel on the Idler-nut.

STEP 18 Mounting the Idler-swivel assembly

Attach the spring 15x5 on both M3x30 screws.
Push the two screws with the springs through the holes in the protrusion on the heatsink. There are no threads inside.
Attach the Idler-swivel assembly on the screws. See the correct orientation of the Idler-nut. The side with version marking must be visible. See the picture.
Tighten both screws. Stop tightening as soon as the screw tips reach the front face of the idler nut.

STEP 19 NTC thermistor: parts preparation

Prepare

NTC thermistor 90 mm x1M3x4T grub screw x1

STEP 20 Assembling the NTC thermistor

On the extruder motor side, insert the NTC thermistor into the hole in the heatsink.
Secure it with the M3x4T grub screw. Screw it all the way in.
Tighten gently, but firmly using two fingers and the short side of the T6 Torx key. Applying more force may cause permanent damage to the thread.

STEP 21 Mounting the Nextruder: parts preparation

Prepare

Nextruder spacer x3M3x10 screw x3Cardboard box x1

Hint: You can use any cardboard box from the kit package.

STEP 22 Protecting the heatbed

Place an empty cardboard box on the heatbed, ensuring it covers as much of the surface as possible.
This will protect the heatbed from falling parts.

STEP 23 Mounting the Nextruder

Screw three Nextruder spacers to the Nextruder holder. Tighten the spacers firmly.
Place the Nextruder assembly on the spacers.
Align the holes in the Nextruder with the spacers and secure it with three M3x10 screws. Do not overtighten the screws.

Ensure the NTC cable is pointing to the left.

STEP 24 Hotend fan: parts preparation

Prepare

Hotend fan x1M3x18 screw x2

STEP 25 Installing the Hotend fan

Attach the hotend fan onto the heatsink with two M3x18 screws on the left side. Tighten the screw gently, but firmly, otherwise the plastic housing may crack.
There is a sticker on the hotend fan, the sticker must be on the rear side of the fan - not visible.
The cable must be pointing towards the lower-left corner.

STEP 26 Guiding the Hotend fan cables

Take the Hotend-cable-clip in the same position as shown and guide the heatsink fan cable together with the NTC thermistor cable through the right cable hook.
Attach the Hotend-cable-clip to the Nextruder holder.
Secure it using two M3x4rT screws.

STEP 27 LoveBoard: parts preparation I.

Prepare

Printhead-cover x1

M3x10 screw (4x)
M3x8rT screw (1x)
M3nS nut (5x)
The list continues in the next step...

Note: Cable color may vary depending on the batch. This does not affect the procedure.

STEP 28 LoveBoard: parts preparation II.

Prepare

LoveBoard x1

STEP 29 Assembling the Loveboard-mount

Locate the U-shaped cable channel on the Loveboard-mount and insert an M3nS nut into the nearby hole.
Use a 2.5mm Allen key to push the nut all the way in.
On the opposite side of the part, insert an M3nS nut and push it into place.

STEP 30 Assembling the Printhead-cover

From the back of the printhead-cover, insert two M3nS nuts into the part.
From the other side of the printhead-cover, insert one M3nS nut into the part.

STEP 31 Assembling the LoveBoard

Place the LoveBoard to the Loveboard-mount. Note the correct orientation - the connectors must be facing downwards.
Align the holes with both parts and secure the board with the M3x8rT screw. Do not overtighten it, it might damage the part.
Take the end of the extruder main cable without the white label.
Turn the Loveboard-mount upside down and connect the Main cable to the LoveBoard.

STEP 32 Guiding the main cable

Twist the main cable half a turn.
Fold the main cable over the LoveBoard to its opposite side.
Turn the LoveBoard assembly upside down.
Guide the main cable over the LoveBoard through the cable channel in the Loveboard-mount.
The end of the textile sleeve must align with the edge of the plastic part.

STEP 33 Covering the LoveBoard

Insert two M3x10 screws into the Loveboard-holder.
Cover the LoveBoard with the Printhead-cover.
Fix both parts together using two M3x10 screws.
Check that there is no large gap or pinched textile sleeve between the parts.

Ensure you insert the screws from the correct side. Use the LoveBoard logo on the board as a reference.

Avoid pinching any wires in the main cable.

STEP 34 Swingarm: parts preparation I.

Prepare

M3x8rT screw x2M3x10 screw x1Fitting M5-4 x1PTFE tube 710 x 4 x 2.5 x1

The list continues in the next step...

STEP 35 Swingarm: parts preparation II.

Prepare

Bowden-bend x1

STEP 36 Guiding the main cable

Carefully open the Main-cable-clip. Be careful not to crack the part.
Insert the main cable into the Main-cable-clip. Note the clip orientation in the photo. The clip is not symmetrical; make sure to attach it as shown.
Place the Main-cable-clip approximately 5 - 15 cm (2 - 6 in) from the end of the textile sleeve and close the clip.
Place the LoveBoard assembly on the cardboard box on the heatbed.
Push the main cable behind the CoreXY assembly in the right rear corner.

Do not move the cable clip to the edge of the textile sleeve as shown in the second photo. Keep it in the same position from the last step.

STEP 37 Mounting the main cable

In the right corner of the printer on the Y motor assembly, locate the hole in the plastic part and align it with the main-cable-clip.
Fix the main-cable-clip with the cable to the hole using the M3x10 screw.

STEP 38 Attaching the LoveBoard assembly

From the back of the Nextruder, attach the LoveBoard assembly to the Nextruder.
Align the hole in the Loveboard-mount with the threaded hole in the top of the heatsink (Nextruder).
Insert and tighten the fitting M5-4 to the heatsink. Use the universal wrench.
From the back of the Nextruder, tighten the two M3x10 screws to secure the LoveBoard assembly.

STEP 39 Mounting the swingarm

Attach the swingarm assembly to the pair of threaded holes on the back panel near the top right corner.
Secure it with two M3x8rT screws.

Do not overtighten the screws, as this may strip the threads.

STEP 40 Attaching the main cable

Position the main cable at the first cutout on the swingarm.
Place one cable tie behind the first cutout on the swingarm, ensuring the correct orientation of the zip strip.
Thread the cable tie through its eyelet, wrapping it around the swingarm and main cable.
Tighten the cable tie as much as possible.
Wrap the cable tie around.

Notice the cutouts on the swingarm.

STEP 41 Inserting the PTFE tube

Push one end of the PTFE tube through the bowden-bend and keep protruding at least 1 cm (0.39 in) of the tube.
Insert the PTFE tube into the fitting M5-4 on the Nextruder. Push it all the way down.
Slide bowden-bend down to cover the fitting M5-4.

STEP 42 Securing the PTFE tube

Route the PTFE tube in parallel with the main cable, ensuring the PTFE tube stays above the main cable.
Secure the PTFE tube and main-cable to the swingarm using two cable ties to the remaining cutouts.
Push the free end of the PTFE tube through the Bowden guide and CoreXY plate downward. Leave the end hanging freely.
Merge the PTFE tube and main-cable with the remaining two cable ties, leaving a 10 cm (3.94 in) distance between them.

Do not pass the PTFE tube through the first cable tie on the swingarm.

STEP 43 Checking the movement

Manually move the XY axes to their end positions several times and ensure that:
The main cable is not too tight and does not pull the Nextruder backward.
The main cable does not form an excessively large arc.
If the cable is too tight or forms a large arc, slightly loosen the screw on the main cable clip and pull the cable upward or downward by a few millimeters. Then, tighten the screw and test again.

STEP 44 Print fan: parts preparation

Prepare

Print fan x1M3x10 screw x2M3nS nut x3

STEP 45 Assembling the fan-shroud

Insert two M3nS nuts from one side into the fan-shroud.
From the other side, insert one M3nS nut into the fan-shroud.
Insert the print fan into the fan-shroud as shown. See the correct orientation of the parts.
Secure both parts together with one M3x25 screw.

Do not overtighten the screws to avoid damaging the fan housing.

STEP 46 Installing the print fan assembly

Attach the print fan assembly to the back of the Nextruder.
Align the holes in the Nextruder bracket with the holes in the fan-shroud.
Secure the fan-shroud to the Nextruder holder using two M3x10 screws.

STEP 47 Hotend: parts preparation

Prepare

Thumb screw x2

STEP 48 Installing the hotend

Route the heatsink fan cable above the first threaded hole in the heatsink.
Insert two thumb screws into the heatsink. Do not tighten them completely. Two turns are enough for now.
Look closely at the underside of the heatsink and find the hole for the hotend assembly.
Insert the hotend assembly tube in the hole and slide the whole thing into the heatsink.
Point the cables to the left according to the photo.
Push the hotend assembly all the way into the heatsink. There should be approximately a 2 mm (0.08 in) gap between the heatsink and the brass part of the nozzle.
While pushing the hotend assembly in, firmly tighten both thumb screws.

Avoid pinching any cable between the screws and the heatsink!

STEP 49 Connecting the heatsink cables

Plug the NTC thermistor cable into the connector above the main cable on the LoveBoard.
Plug the Hotend fan cable into the lower connector in the left row of the LoveBoard.

STEP 50 Connecting the hotend cables

Guide the hotend thermistor through the cable-clip on the Nextruder and connect it to the LoveBoard.
Guide the hotend heater through the cable-clip on the Nextruder and connect it to the LoveBoard.

STEP 51 Connecting the print fan cable

Guide the print fan cable through the channel in the plastic cover.
Create a loop with the print fan cable in the cable area and plug it into the middle connector in the LoveBoard.

STEP 52 Connect E-motor cable

Plug the Nextruder motor (labeled E) to the top-facing connector.
Plug the loadcell cable (lower cable) to the upper connector on the right side of the Nextruder.
Plug the filament sensor (upper cable) to the lower connector.

STEP 53 LoveBoard covers: parts preparation

Prepare

Print-head-cover-right-lever x1M3x10 screw x1M3x6 screw x2

STEP 54 LoveBoard: Wiring check

Before covering the electronics, check the connection of all cables.
Click on the picture to open it in the high-resolution preview.
Squeeze the wiring harness as far inward to the LoveBoard as possible so that it does not protrude out and interfere with the fitting of the cover.

STEP 55 Covering the LoveBoard

Attach the Print-head-cover-left on the left side of the Nextruder.
Secure the cover with one M3x10 screw.
Place the Printhead-cover-right-lever on the right side of the Nextruder.
Secure the cover with two M3x6 screws.
Guide the main-cable through the upper hole on the right side of the back panel assembly.
Leave the end of the cable hanging freely for now.

Do not pinch the cables!

STEP 56 Guiding the main cable

Rotate the printer so that the backside faces you.
Route the main cable through the left hole into the xBuddy box.
Plug the main-cable to the slot on the right side of the xBuddy board.
If the cable does not reach the connector or is too tight, go back to step Guiding the main cable and pull the cable slightly downward from the main-cable-clip.
Secure the cables with the pre-threaded zip ties in the xBuddy box. Carefully cut the excess, avoiding cutting the cables.

STEP 57 Haribo time

Power up and push forward!
Eat the fifth row.

STEP 58 Done

Congratulations! You just successfully assembled the Nextruder.
Let's move to the next chapter.

7Bodywork & Electronics difficulty◷ 1.5-2.5 hr44 stepsofficial ↗0/44›

STEP 1 Tools necessary for this chapter

2.5mm Allen Key 1.5mm Allen Key T10 Torx Key Needle-nose Pliers Flush Cutters (Optional)

STEP 2 Front profiles: parts preparation

Prepare

Front Left Profile x1Front Right Profile x1M3x4rT screw x8

STEP 3 Installing the front right profile

Attach the Front Right Profile to the printer.
Align the profile so that the calibration screw opening and the smaller bolt opening line up with the thread.
Secure the profile to the CoreXY assembly using two M3x4rT screw Fix the profile at the bottom using the two M3x4rT screws.
In case the holes do not align, ensure that the smooth rods are pushed in all the way into the rod mount parts in the base assembly and in the XY assembly on the top.

Ensure you are using the correct profile—it should have one large round opening for the belt tensioning screw.

STEP 4 Installing the front left profile

Attach the Front Left Profile to the printer.
Align the profile so that the openings match. Be careful not to bend the door sensor lever!
Secure the profile to the CoreXY assembly using two M3x4rT screw Fix the profile at the bottom using the two M3x4rT screws.

Ensure you are using the correct profile—it should have two large round openings for the door sensor and the belt tensioning screw.

STEP 5 Top profiles: parts preparation

Top Profile (3x) found in the Metal parts 1/3 package Top rear profile (1x) found in the Metal parts 1/3 package - note the two holes in the part.
M3x4rT screw (8x)
M3x4 screw (4x) with the different head type Nylon Rivet (3x)

STEP 6 Assembling the top profiles I.

Be very careful when handling sharp sheet metal parts to avoid injury or damage.
According to the picture, place the top profile with two holes on the flat side.
Orient the part according to the picture. Use the flange as a guide.
Place any other of the top profiles on the left side. Orient the part according to the picture. Use the flange as a guide.
Attach the two profiles together.
The flange of the front plate (blue arrow) must be inserted under the left universal profile (green arrow), not on top of it.
Align the holes in both parts and join both parts together with the M3x4 screw.
Using the same procedure, join the other two profiles to form a corner, securing them with an M3x4 screw.

STEP 7 Assembling the top profiles II.

Attach the corner profile assembly to the first one, aligning the holes on the flanges with the holes in the profiles.
Join the both profile assemblies using two M3x4 screws.

Ensure the flanges are positioned underneath the profiles.

STEP 8 Aligning the top profiles

Find the profile with two openings in the middle—this part should be positioned at the rear of the printer.
Add the top profile assembly onto the printer, making sure the two openings are facing the back.
The protruding part of the rear profile must be positioned behind the back sheet metal plate.
On the sides and front, the profiles must sit on top of the tabs with threaded openings.

STEP 9 Installing the top profiles

Once all the top profiles are properly aligned, fix them in place using the remaining 8 M3x4rT screws in the corners.
Attach the back panel to the top profile with three nylon rivets.

STEP 10 CoreXY fixing screws: parts preparation

Prepare

M3x4rT screw x4

STEP 11 Fixing the CoreXY assembly

Align the CoreXY assembly so the threaded holes match the screw openings in the rear profiles. You may need to push the assembly upward to align the holes.
Fix the CoreXY assembly using the four M3x4rT screws in the marked openings.

STEP 12 Side sensor base: parts preparation

Prepare

Filament-sensor-body x1Filament-sensor-lever x1Filament-sensor-switch x1M3x10 Screw x110x6x2mm magnet x2

STEP 13 Assembling the side sensor base

Insert one of the magnets into the dedicated opening in the Lever.
Insert the ball into the corresponding opening on the inside of the sensor base.
Insert the lever with the magnet into the Base.
The part with the magnet should be positioned next to the ball.
Fix the lever in place using the M3w washer and M3x10 screw. Tighten it just a few turns for now—enough to hold it in place.

Note that the ball will be attracted to the magnet—ensure it stays securely in place.

Do not fully tighten the screw. Otherwise, the lever will not move and the sensor will not work!

STEP 14 Testing the lever

Verify the lever is able to move freely.
If the lever does not move freely or cannot move at all, loosen the screw by a quarter turn and test the movement again.
The screw must not be fully tightened; otherwise, the lever will not be able to move freely.

STEP 15 Assembling the switch

Read all parts of this step before starting.
Insert the second 10x6x2 magnet into the filament-sensor-switch.
Install the filament-sensor-switch into the filament-sensor-body.
Move the filament-sensor-switch to the left end position so the magnets face each other.
If they attract - pull toward each other: remove the magnet from the filament- sensor switch and flip its polarity. Then check it again.

Make sure the magnets repel - they should push away from one another.

Pro tip: Use one of the thin hex keys or Torx keys to remove the magnet from the filament-sensor-switch.

STEP 16 IR Sensor: parts preparation

Prepare

Side Filament Sensor Cable x1M3x10 Screw x2M3nS nut x2

STEP 17 Connecting the IR sensor

Plug the cable into the IR filament sensor.
On CORE One, the brown cable must connect to the +5V pin.
The white cable connects to the GND pin.

Ensure the connector is oriented correctly before plugging it in!

STEP 18 Installing the IR sensor

First, insert the cable into the groove. The black connector should be approximately in the middle of the sensor base.
Insert the IR sensor itself into the dedicated groove.
The lever must fit into the optical gate part of the sensor.
Using the 1.5mm Allen key, fix the sensor in place with the M2x8 screw.

Make sure neither the connector nor the cables touch the lever, as this could prevent the sensor from functioning correctly.

STEP 19 Installing the side sensor cover

Insert the two M3nS nuts into the designated openings. Use a 1.5mm Allen key to push them all the way in.
Look from the side to ensure the threads in the nuts align with the openings.
Add the cover part onto the assembly.
Fix the cover in place using two M3x10 screws on the sides.

Do not tighten the screw in the middle! Otherwise, the sensor would stop working.

STEP 20 Side filament sensor: parts preparation

Prepare

Side Filament Sensor Assembly x1

STEP 21 Installing the side filament sensor

Install one zip-tie into the marked openings. We will use it to attach a cable underneath the metal profile.
Insert the collet into the marked opening on the sensor assembly.
Attach the sensor assembly onto the PTFE tube in the printer.

Make sure to push the tube all the way in!

STEP 22 Guide the filament sensor cable

Move the sensor assembly up, roughly to the middle of the printer’s frame, to align the cable properly.
Once in position, secure the cable underneath the metal profile using a zip-tie.
Tighten the zip-tie lightly, allowing for cable adjustments if needed later. Cut off the excess zip-tie.
Guide the sensor cable through the dedicated opening to the back of the printer.
On the back of the printer, guide the cable into the xBuddy box. Leave it hanging loosely for now.

STEP 23 Connecting the side filament sensor

Connect the Side Filament Sensor cable into the connector labeled FILAMENT on top of the xBuddy extension board.
You can use needle-nose pliers to assist you, but be careful not to damage the cables.
Use two zip-ties to clamp the cable bundle together in the marked area.
Secure the cables in the highest possible position to ensure they clear the two openings on the sheet metal below.

Do not over-tighten the zip ties or strain the cables too much!

STEP 24 NFC Antenna: parts preparation

Prepare

El-box-cover x1NFCcoil x1

STEP 25 Applying the adhesive film

Peel off the yellow protective film from the adhesive tape.
Apply the film to the flat side of the NFC coil, ensuring it adheres properly.
Peel of the remaining protective layer from the NFC coil.

STEP 26 Installing the NFC Coil

Stick the NFC coil onto the inner side of the El-box cover, approximately as shown in the picture.
The small round connector should be positioned closer to the edge of the cover.
Connect the cable to the board by aligning the connectors and pressing lightly until you feel a click, ensuring a secure connection.

Be careful when connecting the NFC coil cable. Misalignment or excessive pressure can cause irreversible damage.

Make sure to apply equal pressure and do not use flat metal tools to push the NF cable connector in.

STEP 27 Connecting the NFC Coil

Locate the small round connector labeled NFC on the bottom left side of the xBuddy board.
Connect the NFC coil cable to the board by aligning the connectors and pressing lightly until you feel a click.

STEP 28 Wiring check

Use the pictures as a reference to verify your electronics connections.
Otherwise, there is a risk of damage to the printer!

Make sure that all connectors are fully inserted and PSU cables properly tightened.

STEP 29 Preparing the electronics cover

Push two M3x10 screws through the El-box-cover.

STEP 30 Installing the electronics cover

If so, rearrange the cables to allow clear access.
Align the cover with the opening in the xBuddy box and fix it in place by tightening the screws.
Route the NFC cable through the space between the Ethernet connector and the PSU power cables.

Ensure the threaded holes on the bottom of the xBuddy box are not obstructed by cables.

Avoid running it through the Ethernet connector or the power cables. The cable may be damaged when covering the xBuddy box.

STEP 31 Buddy3D Camera Note

For future Buddy3D Camera users:
If you plan to use the Buddy3D Camera, you have the USB cable installed already.
For detailed information on how to mount and connect the Buddy3D camera, return to this guide: Buddy3D Camera for CORE One Installation

STEP 32 xBuddy cover: parts preparation

Prepare

Sheet metal back cover x1

STEP 33 Installing the xBuddy cover

Arrange the cables inside the xBuddy box as shown in the picture.
Carefully cover the xBuddy box by first sliding the bent part of the cover into the box.
Double-check the NFC coil cable position.
Secure the xBuddy box cover using the six M3x4rT screws.

Avoid pinching the cables and make sure to insert the cover perpendicular to the xBuddyboard.

STEP 34 Installing the rear cover

Align the rear sheet metal cover so that the cables can run through the "tray".
Place the rear sheet metal cover into the recess. Push it toward the printer, then move it upward to engage it.
There are four tabs that should engage into the printer’s chassis.
Secure the rear cover in place using two M3x4rT screws from inside the printer.

STEP 35 Right side: parts preparation

Prepare

Right side sheet metal x1M3x8rT screw x4Any cardboard box x1

Tip: A Prusament box works well.

STEP 36 Installing the spoolholder puck

Place the Puck-universal on the cardboard box so that the screw holes face upward.
Carefully place the right panel onto the Puck-universal, positioning it at the center of the box.
Align the holes in the Puck-universal with the holes in the right panel.
Fasten the Puck-universal using four M3x8rT screws.
Screws may feel resistant when tightening, as they cut their own thread inside the part.

STEP 37 Right handle: parts preparation

For the following steps, prepare:
Side Handle (1x) found in the Printed parts package M3x8rT screw (2x)
Collet (1x) found in the Electronics & Fasteners package PTFE Tube 4 x 2.5 x 45 mm (1x) found in the CoreXY parts + Hinges set package (together with hinges parts)
Nylon Rivet (11x)

STEP 38 Installing the collet

Insert the collet into the handle.
Push it all the way in.

STEP 39 Mounting the handle

Place the right-side metal sheet assembly on the right side of the printer. Ensure the U-shaped cutouts are facing upwards.
Attach the right handle to the right metal sheet.
Push one M3x8rT screw through the rear hole in the handle and the metal sheet.
Attach the side filament sensor assembly on the screw.
Tighten the screw just slightly—the nut must remain free to move.
Align the side filament sensor with the front screw hole in the metal sheet and the handle.

Do not pull the side sensor assembly too far; bring the right side metal sheet as close as possible.

STEP 40 Fixing the right side

Using the second M3x8rT screw, secure the right handle and the side filament sensor to the right metal sheet.
Secure the side sheet metal to the printer using the 11 Nylon rivets.
Insert the short PTFE tube 4 x 2.5 x 45 into the collet. Push it all the way in.
Part of the PTFE tube will remain protruding from the handle.

STEP 41 Left side: parts preparation

For the following steps, prepare:
Left side sheet metal (1x) found in the Metal parts 2/3 package Side Handle (1x) found in the Printed parts package M3x5rT screw (2x)
Nylon rivet (11x)

STEP 42 Installing the left side

Align the handle with the threaded openings in the sheet metal.
Attach the handle using the two M3x5rT screws.
Secure the side sheet metal to the printer using 11 nylon rivets.

STEP 43 Haribo time

Well done—fuel up for the next challenge!
Eat the sixth row of gummy bears.
We are getting close to the finish line! But hands off those last gummies!

STEP 44 Done

Congratulations! You’ve successfully assembled the entire body.
Let's move to the next chapter.

8Trim, Door & xLCD difficulty◷ 1.5-2 hr46 stepsofficial ↗0/46›

STEP 1 Tools necessary for this chapter

For the following steps, prepare:2.5mm Allen Key T10 Torx Key Needle-nose pliers

STEP 2 Top cover: parts preparation

For the following steps, prepare:
Top cover (1x) found in the Plexi set package Vent cover (1x) found in the Plexi set package M3nN nut (3x)
Insulating insert (3x) found in the Electronics & Fasteners package This part may come in either gray or black. However, the shape is identical, and it does not affect the procedure.
M3x12rT screw (3x)
Nylon rivet (4x)
Upg-vent-block (1x)

STEP 3 Removing the foil

First, remove the protection foil from both the plastic sheets.
Flip the parts around and remove the protective foil from the other sides.

STEP 4 Test-fitting the top cover

Lay down the top cover onto the printer.
The part with the vent openings should be oriented towards the front of the printer.
If oriented correctly, the cover will align with the recess, and the bolt heads in the corners will fit into the cutouts.
If the bolt openings don't align, flip the cover.
Spoiler alert: The cover isn't symmetrical!

STEP 5 Assembling the top cover I.

Run all three M3x12rT screws through the insulating inserts.
Insert the screws with the inserts through the three slot openings in the vent.

Make sure the flanged part of the insert is oriented toward the screw head.

STEP 6 Assembling the top cover II.

Align the vent cover.
Sliding the vent cover to the left will open it.
Sliding the vent cover to the right will close it.
Hand-tighten the rightmost M3nN nut onto the M3x12rT screw to fix the cover in place. Do not tighten it fully.
Attach the Upg-vent-block to the ventilation cover. Make sure that it is positioned correctly. Ensure that the vent block never overlaps with the opened vent.
The Upg-vent-block lever will face inside the printer so that the printhead can open and close the vent cover.
Secure the Upg-vent-block on the ventilation cover with M3nN nuts. Use the needle-nose pliers or universal wrench to hold the nuts while tightening the screws.
The screw must be just tight enough to remove the slack. It must remain loose, or the ventilation cover can not open and close properly.

Note that the vent cover is not symmetrical; ensure that it is positioned as shown in the photos.

STEP 7 Testing the ventilation

Try moving one of the three screws with your hand.
The vent openings must open and close smoothly without effort.
If movement is difficult, loosen the screw that is restricting it.

STEP 8 Installing the top cover

Align the cover with the recess on the printer, ensuring the vent points forward.
Secure the cover to the frame using four nylon rivets in the marked openings.
There are eight openings, but four rivets should be sufficient.

STEP 9 Side covers: parts preparation

For the following steps, prepare:
Side Cover (2x) found in the Plexi set package Nylon Rivet (10x)

STEP 10 Removing the foil

Remove the protective foil from both the side covers.
Remove the protective foil from the other sides of both the side covers.

STEP 11 Covering the left side

Align the cover with the recess on the left side of the printer.
The protruding screws on the printer must align with the larger openings in the cover.
Secure the cover to the frame using five nylon rivets in the marked openings.

STEP 12 Covering the right side

Align the other cover with the recess on the right side of the printer.
Secure the cover to the frame using five nylon rivets in the marked openings.

STEP 13 xLCD: parts preparation

For the following steps, prepare:
xLCD (1x) found in the Electronics package xLCD Front Cover (1x) found in the Printed parts package xLCD Display-mount (1x) found in the Printed parts package
Knob (1x) found in the Printed parts package 3x8sT Screw (4x)
Faston connector (1x) found in the Electronics package

Note: Your kit may include the updated injection-molded xLCD Display Mount. Keep this in mind for the following steps.

STEP 14 Important: new xLCD display mount

As of March 2026, the xLCD Display Mount has been updated.
Your kit may include the new version.
Compare your part with the reference photo to identify the version:
Older version (3D-printed):
Surface is rough and layered.
New version (injection- molded): Surface is smooth.
Changes related to the new part are detailed in the relevant steps of the manual. Read carefully and follow the instructions based on the version you have.

STEP 15 Assembling the xLCD I.

We recommend placing the front cover face down on a cardboard box edge or desk to create space for the encoder knob.
Remove the protective foil from the xLCD.
Insert the xLCD into the front cover.

STEP 16 Assembling the xLCD II.

Cover the assembly with the rear part.
If you have an older version of the printed rear cover, it must hook by the xLCD itself in the corner. With the up-to-date version, the rear part can be simply laid down.
Fix the parts together using JUST THREE 3x8sT screws in the marked openings.

Do not insert the screw into the fourth opening next to the long slot for the xLCD connector, visible through the cutout. Leave it empty for now.

STEP 17 Installing the FE Faston connector

Let’s move on to the fourth screw opening—this is where we will attach the grounding faston connector.
Using needle-nose pliers, carefully maneuver the grounding faston connector over the screw opening, ensuring the holes line up.
Secure the connector in place using one 3x8sT screw, making sure it stays lined up as indicated.
To prevent damaging some of the surrounding electronic components, be careful and make sure the connector doesn’t spin, while tightening it.

STEP 18 Installing the LCD knob

There is a flat part on the encoder shaft. Rotate the encoder so that the flat part is facing up.
There is a small gate scar on the injection-molded knob, which can serve as an orientation mark.
Attach the knob onto the shaft, making sure the mark on the knob is facing up.

STEP 19 xLCD bezel: parts preparation

For the following steps, prepare:
xLCD (1x) found in the Electronics package M3nS nut (2x)
The M3nS nuts are not required for the new injection-molded part.
M3x6 screw (2x)
Bezel (1x) found in the Metal parts 2/3 package

STEP 20 Mounting the xLCD I.

For the new injection-molded xLCD display mount: M3nS nuts are not used.
Old printed xLCD-display-mount: Insert the two M3nS nuts into the dedicated openings on the back of the xLCD assembly, Push the nuts all the way in until the threads line up with the screw openings.
Attach two M3x6 screws into the openings. Do not screw them all the way in.
New injection-molded xLCD display mount: Screws thread directly into the plastic, so slight resistance is normal.
Leave a gap of at least 3 mm under the screw heads. mm under the screw heads.

STEP 21 Mounting the xLCD II.

Hook up the xLCD assembly onto the Bezel.
Insert the screw heads into the keyhole openings.
Slide the xLCD assembly so that the screw heads engage into the narrower parts of the keyholes.
If assembled correctly, the LCD should be pointing up...
...While the bent lip on the Bezel is on top.
Push the screws all the way into the narrow part of the keyhole on both sides. Then, tighten the screws.

STEP 22 Installing the xLCD assembly

Put the xLCD assembly in front of the printer, as pictured.
Pull the appropriate cables out from the front of the printer to make connecting them easier.
There is a small red tab on the main connector. This tab must be oriented towards the triangle symbol on the PCB.
Connect the main connector into the xLCD.
Connect the grounding faston connector.

STEP 23 Securing the xLCD assembly

Gently lift the xLCD assembly into the upward position.
Proceed carefully to ensure none of the cables get pinched or disconnected.
Hook the tiny tab on the left side of the bezel behind the left vertical profile of the printer.
Gently lift the bottom part of the xLCD assembly to allow for smoother tab engagement and extra wiggle room.
Hook the tab on the right side into the printer’s right profile.

STEP 24 Door seal: parts preparation

For the following steps, prepare:
Side door seal (2x), longer ones found in the Electronics & Fasteners package Top door seal (1x), a shorter one found in the Electronics & Fasteners package The color of the protective layer may vary.

STEP 25 Attaching the top seal

Take the SHORTER seal.
Peel off the start of the protective foil. No need to remove it entirely yet.
No need to remove it entirely yet. For easier installation, you can peel it off gradually as you go.
Start applying the seal along the top edge of the printer’s frame.
Begin offset from the corner by a distance equal to the seal thickness.
Apply the seal along the top edge, leaving the end offset from the corner, just like on the other side.

STEP 26 Attaching the side seals

Apply the longer door seal, starting from the end of the seal on top.
Work your way from the top down.
Use the needle-nose pliers to trim any excess seal that overlaps with the LCD panel at the bottom.
Using the same technique, apply the remaining long seal along the left edge of the printer’s frame.

STEP 27 Magnet holders: parts preparation

For the following steps, prepare:
M3x5rT screw (2x)
M3nS nut (2x)
20x6x2 Magnet (2x) found in the Electronics & Fasteners package Keep the magnets apart at a sufficient distance. They can break each other!
Magnet Holder (2x) found in the Printed parts package

STEP 28 Assembling the magnet holders

Insert the M3nS nuts into the corresponding openings in the magnet holders.
Push the nuts all the way in, until the thread aligns with the screw opening.
Insert the magnets into the corresponding pockets in the holders. Push them all the way in.
The orientation of the magnets does not matter.

STEP 29 Installing the magnet holders

From the inside of the printer, insert the magnet holder assembly into the corresponding bottom opening in the right-side metal profile.
Secure the assembly in place using the M3x5rT screw.
Using the same technique, install the other magnet holder into the top opening on the right side.

Ensure the protruding rectangular pocket fits into the cutout.

STEP 30 Hinges: parts preparation

For the following steps, prepare:
Door-hinge-in (2x) found in the CoreXY + Hinges set package Door-hinge-out (2x) found in the CoreXY + Hinges set package Hinge Pin 2 x 40 mm (2x) found in the Electronics & Fasteners package M3x5rT screw (2x)

STEP 31 Installing the door-hinge-in parts

From the inside of the printer, insert the door-hinge-in into the bottom rectangular opening in the left-side profile. The protruding part should pass through to the front.
Fix the door-hinge-in in place using the M3x5rT screw.
Using the same technique, install the other door-hinge-in into the opening on top.

STEP 32 Installing the door-hinge-out I.

Align the door-hinge-out with the door-hinge-in.
The chamfered end of the hinge pin should be inserted first to make assembly easier.
Insert the pin from the top of the door-hinge-out, guiding it through the door-hinge- in until it is fully inserted.
Use the tip of needle-nose pliers to press the pin in securely.

STEP 33 Installing the door-hinge-out II.

Using the same technique, install the bottom door-hinge-out to complete the hinge assembly.
Look into the grooves on the door-hinge-out parts and verify that the pins are fully inserted.
No part of the pin should be visible above the bottom surface in the groove.
Open up both the hinges.

STEP 34 Door panel: parts preparation

For the following steps, prepare:
Door (1x) found in the Plexi set package The door panel is pre-labeled CORE ONE. Do not worry, this is intended! You will apply the upgrade + decal as the final step.
Door handle (1x) found in the Metal parts 2/3 package M3x5rT screw (4x)

STEP 35 Important: new parts

Starting May 2026, the door handle is supplied in a screw-mounted version (instead of the glued version).
If your printer is from this period, check the package contents.
If it includes parts for the screw- mounted version, you will find:
Door handle plate (1x)
M3x8rT screw (2x)
You can still assemble the door handle using the glued method, but the screw-mounted version provides a more secure, long-lasting fit.

STEP 36 Door panel: removing the protective film

The door panel has protective film on both sides. One covers the entire surface, the other just the center area.
Peel off the film covering the entire door; it’s lightly transparent.
You can remove the center protective film (white) now or after mounting the panel to protect the surface during handling.
This protective film does not interfere with the installation of the hinges or handle.

STEP 37 Door handle installation method selection

Continue with the section corresponding to your printer version:
If your printer includes a door handle plate, continue by pressing Next button.
Otherwise, continue to Installing the door panel.

Do not continue until you identify the correct installation method based on the parts included in your package.

STEP 38 Installing the door handle (screw-mounted)

Take the door handle.
Use a thin T6 Torx key to pierce the adhesive layer through the screw hole from the underside of the door handle.
Proceed the same on the second hole.
Place the door handle next to the door panel, as shown in the picture.
Align the holes in the door handle with the holes in the door panel.
Slide the door handle onto the panel.

Make sure the Prusa logo is now on the top side.

STEP 39 Securing the handle (screw-mounted)

Lift the door panel into a vertical position and hold it steady.
Insert the door handle plate into the grip side of the handle (the outward-tilting side).
Align these columns with the screw holes in the door panel and the door handle.
Secure the handle with two M3x8rT screws.
Tighten firmly, but gently.
Some following steps may also describe a glued installation method for the door handle. Since your door handle is already installed using the screw-mounted version, these instructions do not apply to this assembly.

Make sure the threaded columns on the plate face away from the panel.

STEP 40 Installing the door panel

Align the door with the hinges. The cutouts on the door should fit into the grooves on top and bottom of the leaves.
Slide the door all the way into both the hinges.
Fix the door to the hinges using four M3x5rT screws. Start with the top one. Then, do the bottom.

Make sure the door is oriented so that the signs on the door are pointing outward.

STEP 41 Assembling the door handle (glued version)

This step includes an adhesive (glued) mounting method only. If your door handle is already screw-mounted, this step does not apply to your assembly.
Let's move onto the handle. Remove the protective foil from both the adhesive strips on the inside.
The part with the adhesive strip will go onto the back of the door. But do not attach the handle yet!
Wait for the upcoming step! We have to align the handle first!

STEP 42 Securing the door handle (glued version)

This step includes an adhesive (glued) mounting method only. If your door handle is already screw-mounted, this step does not apply to your assembly.
Align the handle so that the front chamfered part is flat to the door. The top of the handle must be flush with the door.
While pushing the handle against the door to keep it aligned, slowly rotate it counterclockwise until the adhesive strips bond to the door.
Push the door and handle together firmly in the adhesive strip areas to ensure a secure attachment.

STEP 43 Attaching the sticker: Parts preparation

For the following step, prepare:
CORE One+ plexi sticker The CORE One+ plexi sticker is in the CORE One+ Upgrade box

Note: From 01/2026, the "+" symbol comes pre-installed on the printer door. If your printer is from an earlier date and does not have the symbol, follow this step.

STEP 44 Attaching the sticker

Remove the sticker from the blue base.
Align the sticker with the ONE and gently but firmly apply pressure on the sticker.
Carefully peel off the transparent layer and make sure that + is not peeling off.

STEP 45 Haribo time

Hard work deserves sweet results!
Eat the seventh row.
But do not eat the rest yet.

STEP 46 Done

Congratulations! You have successfully assembled your Prusa CORE One+.
Let's move to the final chapter.

9Calibration & First run difficulty◷ 30-60 min21 stepsofficial ↗0/21›

STEP 1 Belt tensioning

This chapter will guide you through calibrating and preparing the printer for its first run. Starting with tensioning the belts:
The left screw adjusts the upper belt.
The right screw adjusts the lower belt.
Double-check that the M3x30 screws in the belt tensioners were lubricated during assembly.
Adjusting belt tension (CORE One)

WARNING: Incorrect procedure may result in damage to plastic parts or seizing of screws. Before adjusting the belt tension, read the dedicated article:

Do not forget to come back here after adjusting the belts.

STEP 2 Installing the spoolholder: Parts preparation

For the next step, prepare:
O-ring Spoolhoder-static The spool holder and the O-ring are in the same bag.

STEP 3 Attaching the print sheet and spoolholder

Attach the sheet by first aligning the rear cutout with the locking pins on the back of the heated bed. Hold the sheet by the front two corners and slowly lay it down onto the heated bed - watch your fingers!
Keep the print sheet clean for optimum performance.
#1 cause of prints detaching from the print surface is a greasy print sheet. Use IPA (Isopropyl alcohol) to degrease it if you have touched its surface before.
Put the O-ring onto the Spoolholder-static.
Push the Spoolholder-static into the Puck-universal dock and lock it in by turning it clockwise.

Make sure there is nothing on the heatbed. The heatbed must be clean. Any dirt can damage the surface of both the heatbed and the print sheet.

STEP 4 Firmware update

All printers come with a USB drive containing the latest firmware. However, it is recommended to check and possibly upgrade the firmware version every few weeks.
Visit the help.prusa3d.com page.
Navigate to the Prusa CORE One+ page.
Download the latest firmware version.
Save the firmware file (.bbf) onto the bundled USB drive.

STEP 5 Turning on the printer

Insert the USB drive included in your kit into your printer.
The included USB drive contains the latest firmware file.
Connect the power cable and plug the printer into a wall outlet.
Turn the printer on using the switch on the back.
The printer will now detect if a new firmware file is available on the USB drive.
If the "New firmware available" screen appears, hit FLASH by pressing the rotary knob to upgrade to the latest firmware.
If no such message appears, the printer is running the latest firmware already.
Proceed to the next step.

STEP 6 Setting up the printer: Intro

The printer displays on the screen a prompt to select your language. Use the control knob or touchscreen to set your preference.
After selecting your language, the printer will display the welcome screen. Hit OK to continue through the setup process.
The next screen will prompt you to select your printer model COREONE. Hit Done to continue.

STEP 7 Setting up the printer: Network setup

The Network Setup screen will ask you to connect to a Wi-Fi network using our official Prusa mobile app.
Read more on prusa.io/app.
If you select No, the printer will show alternative ways to connect to Wi-Fi. This step is optional and can be done later.
You can skip this screen and set up the network connection later.

STEP 8 Wizard: Intro

The printer will prompt you to run self-tests and calibrations for all important components. The entire process takes a few minutes, with some parts requiring direct user interaction.
Hit YES to begin the self-test and follow the instructions on screen.
During the self-test, keep the door closed until you are prompted. Opening the door will interrupt the process.
There are HOT and moving parts inside during the self-test.
The printer will begin by testing all the fans. Be aware—it can get quite noisy for a while!

STEP 9 Wizard: Door Sensor Calibration

The first part that requires your interaction is the door sensor calibration. To begin, hit Calibrate and follow the on-screen instructions.
You’ll be prompted to gradually tighten the sensor tension screw from its default loose position - usually in half-turn steps, possibly several times during calibration.
After each adjustment, observe the door sensor switch emerging from the front profile hole.
Repeat the procedure until the door sensor is correctly adjusted - meaning it switches at a hand-gap distance. Then hit Continue.
Once the sensor is properly calibrated, you should hear an audible click from the door sensor area when opening and closing the door.

STEP 10 Wizard: Loadcell Test

The next step of the wizard will prompt you to touch the nozzle to test and calibrate the Loadcell. During this procedure, the parts of the printer are not heated up so that you can touch them. Hit Continue.
Loadcell calibration requires the door to be open, as you must interact directly inside the printer.
Tap the nozzle from below. In case the Loadcell does not detect the touch, you will be prompted to repeat the step. Otherwise, you will see Loadcell test passed OK when it succeeds.
To allow the printer to continue with the Wizard, close the door.

Do not touch the nozzle yet, wait until prompted by the Tap nozzle NOW message.

STEP 11 Wizard: Gearbox Alignment

Once you get to the Gearbox Alignment part, select Continue and follow the on- screen instructions.
Loosen the three screws on the front of the gearbox by 1.5 turns.
The printer will go through the automatic gearbox alignment. This process can’t be seen from the outside.
Once prompted, tighten the three screws in the pattern indicated on the screen.

Make sure the idler lock (swivel) is unlocked from the idler door.

STEP 12 Wizard: Filament Sensor Calibration

Check the manual switch on the filament sensor. Make sure that it is ON.
During the filament sensor calibration, you will need to use a short piece of filament. Prepare the filament and select Continue.
There should be no filament inside the extruder before the calibration process starts.
Place a spool of filament onto the spool holder on the right side of the printer.
When prompted, begin inserting the filament into the PTFE tube located beneath the right handle.
Remove the filament after the calibration finishes.

STEP 13 Wizard complete

Congratulations! The Wizard is complete. Now it’s time to test some prints.

STEP 14 Haribo time

Victory tastes like gummy bears!
Enjoy the rest. You’ve earned this.

STEP 15 Handbook

Read the 3D Printing Handbook dedicated to your printer and follow the instructions to set up the printer and prepare it for your first print.
The latest version is always available at help.prusa3d.com.
Read the Disclaimer and Safety instructions chapters.

STEP 16 Give us feedback

We know you’re eager to start printing, but we’d really appreciate it if you could take 3–4 minutes to share your thoughts on this manual: how clear it was, how easy it was to follow, and any ideas to improve it.
This feedback is a little different from the usual comments you might leave on individual steps.
Share your feedback here.
Thank you for helping us make our manuals even better!

STEP 17 Prusa knowledge base

If you encounter any problems at all, don't forget you can always check out our knowledge base at help.prusa3d.com We're adding new topics every day!

STEP 18 Join Printables!

Don't forget to join the biggest Prusa community! Download the latest models in STL or G-code tailored for your printer. Register at Printables.com Looking for inspiration on new projects? Check our blog for weekly updates.
If you need help with the build, check out our forum with a great community :-)
All Prusa services share one user account.
Manual changelog Manual changelog

STEP 1 Version history

Versions of the Prusa CORE One+ kit manual:
11/2025 - Initial version 1.00 03/2026 - Updated to version 1.01 05/2026 - Updated to version 1.02

STEP 2 Changes to the manual (1)

03/2026 - new xLCD display mount Added instructions for the new injection-molded xLCD display mount.
Manual version 1.01 Manual changelog

STEP 3 Changes to the manual (2)

05/2026 - Door handle installation.
Added separate instructions for screw-mounted and glued door handle installation. Conditional flow added to guide users to the correct procedure based on supplied parts.
Manual version 1.02 219 Notes:
220 221 Notes:
222 223 Notes:
224

Notes & References

A scratchpad for the whole build — shopping reminders, calibration numbers, mod ideas. Saved in this browser; use Export notes up top to download everything (your general notes + every step note + progress) as a text file.

Build the CORE One+,every single step

Notes & References

Build the CORE One+,
every single step