Skip to main content
  1. 13/17mm spanners
    • 13/17mm spanners

    • 3.6mm flathead screwdriver

    • Needle-nose pliers

    • 2.5 and 1.5mm Allen key

  2. Z-axis-top-left
    • Z-axis-top-left

    • Z-axis-top-right

    • Z-axis-bottom-left

    • Z-axis-bottom-right

    • Z-screws-covers

    • Use the hole for 8 mm smooth rod as an orientation key in the next steps.

  3. Place parts on the frame as shown in the picture. The small circular opening should be closer to the frame outer edge. Note the frame orientation (PRUSA logo has to be visible). All screws in this step are M3x10 (6 pcs).
    • Place parts on the frame as shown in the picture. The small circular opening should be closer to the frame outer edge.

    • Note the frame orientation (PRUSA logo has to be visible).

    • All screws in this step are M3x10 (6 pcs).

    • Use 2.5mm Allen key to tighten the parts to the frame. The screws must be perpendicular to the frame.

    • Tighten them gently, no superhuman force required.

    • Note: If you have troubles tightening the screws, try to place them on the other side of the frame to clean the thread. Then place them again from the previous side. Proceed with caution, or you might break the screw.

  4. Remove the trapezoid nuts from the motors. Screw the Z-screw  covers onto both leadscrews. Covers should be screwed fully to the motor, but not too tight! The motor should keep spinning freely.
    • Remove the trapezoid nuts from the motors.

    • Screw the Z-screw covers onto both leadscrews.

    • Covers should be screwed fully to the motor, but not too tight! The motor should keep spinning freely.

  5. Place the Z motors on the frame. Z motor left (labeled with Z axis left )
    • Place the Z motors on the frame.

    • Z motor left (labeled with Z axis left )

    • Z motor right (labeled with Z axis right, longer wire)

    • Ensure the correct position of the motors (left/right).

    • Ensure the wires are not pinched between the motor and the holder (see detailed photo).

  6. Use M3x10 screws (8 pcs) and M3w washers (8 pcs). Use 2.5mm Allen key to tighten the motor to the printed part.
    • Use M3x10 screws (8 pcs) and M3w washers (8 pcs).

    • Use 2.5mm Allen key to tighten the motor to the printed part.

  7. Insert M3 nuts (4 pcs) in the printed parts as shown in the picture. Nuts orientation does not matter.
    • Insert M3 nuts (4 pcs) in the printed parts as shown in the picture.

    • Nuts orientation does not matter.

  8. Use M3x12 screws (4 pcs) to tighten nuts in place. Use 2.5mm Allen key to tighten the screws.
    • Use M3x12 screws (4 pcs) to tighten nuts in place.

    • Use 2.5mm Allen key to tighten the screws.

  9. In the following steps, use the shortest rods (320 mm).
    • In the following steps, use the shortest rods (320 mm).

  10. Insert Z-rods (the shortest ones) inside the Z-axis-bottom parts. Insert Z-rods (the shortest ones) inside the Z-axis-bottom parts. Insert Z-rods (the shortest ones) inside the Z-axis-bottom parts.
    • Insert Z-rods (the shortest ones) inside the Z-axis-bottom parts.

  11. Carefully slide the X-axis on rods and trapezoid screws. By rotating both screws simultaneously let the X-axis to slide until both trapezoid screws are exposed as in the picture. Insert the X-axis very carefully, perfectly in axis with the bearings and with  a minimal force. Insert the X-axis very carefully, perfectly in axis with the bearings and with  a minimal force.
    • Carefully slide the X-axis on rods and trapezoid screws. By rotating both screws simultaneously let the X-axis to slide until both trapezoid screws are exposed as in the picture.

    • Insert the X-axis very carefully, perfectly in axis with the bearings and with a minimal force.

  12. Place parts on the frame as in the picture. Ensure the smooth rod is aligned with the top surface of the Z-axis-top part. Check both sides of the Z-axis. Use 2.5mm Allen key to tighten the parts to the frame.
    • Place parts on the frame as in the picture.

    • Ensure the smooth rod is aligned with the top surface of the Z-axis-top part. Check both sides of the Z-axis.

    • Use 2.5mm Allen key to tighten the parts to the frame.

    • Check both leadscrews in the upper part of printer, they shouldn't touch the edges of the printed part. If so, release the motor holder at the bottom and slightly move it.

    • All screws in this step are M3x10 (4 pcs).

  13. Insert the zip ties in the holes at the bottom of the frame. Tie the cables to the frame as shown in the picture. Note that the left Z-motor cables are tied with the last zip tie.
    • Insert the zip ties in the holes at the bottom of the frame.

    • Tie the cables to the frame as shown in the picture.

    • Note that the left Z-motor cables are tied with the last zip tie.

  14. Use pliers and cut the excess zip tie.
    • Use pliers and cut the excess zip tie.

    • Note the position of the connecting zip tie.

  15. Grab the Y-axis assembly in your hand and slide it into the frame. You should be able to lift the constructed printer as a whole. Tighten the M10n nuts to the frame.
    • Grab the Y-axis assembly in your hand and slide it into the frame.

    • You should be able to lift the constructed printer as a whole.

    • Tighten the M10n nuts to the frame.

    • Ensure that there is a washer between a nut and the frame on both sides.

    • Ensure the correct orientation of the Y-axis assembly and the frame (longer part should be on the side with Z-axis motors).

  16. DON'T TRIM THE BELT unless you are asked in the instructions!!! Insert the flat part of the X-GT2 belt (longer one)  into the X-carriage as in the picture.
    • DON'T TRIM THE BELT unless you are asked in the instructions!!!

    • Insert the flat part of the X-GT2 belt (longer one) into the X-carriage as in the picture.

    • A reference video is included at step 25 covering steps 16-24.

    • Note that there is no belt going out of the X-carriage, it's IMPORTANT.

  17. Guide the belt around the pin as shown in the picture. Insert the belt all the way into the belt holder as shown in the picture.
    • Guide the belt around the pin as shown in the picture.

    • Insert the belt all the way into the belt holder as shown in the picture.

    • Note that there is no belt going out of the X-carriage, it's IMPORTANT.

  18. Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back. Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back.
    • Guide the X-axis belt through the X-end-idler, around the 623h bearing with the housing and back.

  19. Guide the X-axis belt through the X-carriage.
    • Guide the X-axis belt through the X-carriage.

  20. Guide the X-axis belt through the X-end-motor, around the  GT2-16 pulley and back. Guide the X-axis belt through the X-end-motor, around the  GT2-16 pulley and back.
    • Guide the X-axis belt through the X-end-motor, around the GT2-16 pulley and back.

  21. Remove the two M3x18 screws. Rotate the motor counter-clockwise as shown in the picture.
    • Remove the two M3x18 screws.

    • Rotate the motor counter-clockwise as shown in the picture.

    • This step is illustrative, you don't need to remove the frame.

  22. Use pliers to tighten up the X-axis belt.
    • Use pliers to tighten up the X-axis belt.

    • Insert the flat part of belt as shown in the picture.

  23. Guide the belt around the pin as shown in the picture. Push the belt all the way into the X-carriage.
    • Guide the belt around the pin as shown in the picture.

    • Push the belt all the way into the X-carriage.

    • The belt shouldn't be tight at the moment.

  24. Rotate the motor back.
    • Rotate the motor back.

    • Screw in the removed M3x18 screws.

    • If you have to apply too much force and are experiencing troubles, rotate the motor back, repeat previous step while loosening the belt.

    • The belt should be quite tight, it should 'ping' like a music string.

    • This step is illustrative, you don't need to remove the frame.

    • Insert the flat part of X-GT2 belt (longer one) into the X-carriage, around the pin. Guide the X-axis belt through X-end-idler, around the 623h bearing with the housing and back. Guide the X-axis belt through the X-carriage. Guide the X-axis belt through the X-end-motor, around GT2-16 pulley and back.

    • Remove the two M3x18 screws. Rotate the motor counter-clockwise.

    • Insert the flat part of the belt around the pin.

    • Rotate the motor back. Screw in the removed M3x18 screws.

    • Video is available in an online (digital) version only.

  25. Gently tighten both screws until slight force is applied on both smooth rods.
    • Gently tighten both screws until slight force is applied on both smooth rods.

    • By tightening/releasing both screws you can slightly adjust the position of the right leadscrew (see its position in the Z-axis-top-right printed part).

  26. Congratulations! You've just assembled the Z-axis.
    • Congratulations! You've just assembled the Z-axis.

    • You can continue by assembling the Extruder in the next chapter - 5. Extruder Assembly

Finish Line

555 other people completed this guide.

Josef Prusa

Member since: 01/05/2015

141 Guides authored

Team

Prusa Research Member of Prusa Research

Community

3 Members

355 Guides authored

15 Comments

Having a M3 tap on hand was very important for me to be able to complete this section. It should be on the recommended tool list for the build (like a good caliper). This was still my favorite step. Seeing the printer start to look like one was very satisfying. :)

Jasmin Lévesque - Reply

Agree! M3 tap will help a lot! I tapped the holes with the screws, but will definitely get a set of taps for future printed parts.

Waldo -

It took me 1:50 with plenty of problems.

Jake Block - Reply

45 Minutes... No Problems.

James Miller - Reply

1 hour tops. Only 1 issue, one of the nuts that slide into the holder would not go in far enough so the screw would not line up and go in. Maybe these cavities should be slighter deeper so the nuts can actually go in past the center line, that way they have a little movement until locked down.

Randy H - Reply

Add Comment

View Statistics:

Past 24 Hours: 7

Past 7 Days: 83

Past 30 Days: 407

All Time: 54,515