4. Z-axis assembly

Relevant for:

MK3S+

Last updated 2 years ago

Difficulty

Very easy

Steps

Available languages

Step 1 Tools necessary for this chapter

⬢Needle-nose pliers for tension check.

⬢2.5mm Allen key for M3 screws

Step 2 Z-axis: assembling motor holders

WARNING: Printed parts aren't the same! There is a left and right oriented piece. See the markings on the parts. Also note the correct orientation of the frame, the "PRUSA" logo and the safety sticker must be facing towards you.

⬢For the following step, please prepare:

⬢Z-axis-bottom-left (1x)

⬢Z-axis-bottom-right (1x)

⬢M3x10 screw (6x)

Place the printed parts next to the frame. See the left (L) and right (R) marking on the printed parts.

⬢Tighten each printed part with M3x10 screws. Don't use excessive strength during tightening! In case of increased resistance, try to place the screws from the other side to "clean up" the hole. Then return to the front side.

Step 3 Placing the Z-screw covers

⬢For the following steps, please prepare:

⬢Z-axis motor (2x)

Note each Z-axis motor has different cable length. The shorter one must be on the left side, longer on the right side.

⬢Z-screw-cover (2x)

⬢Remove the trapezoidal nuts from the motors. DON'T THROW them away, you will need them!

The new kit units no longer have trapezoidal nuts on the motor rods. They are included inside the motor kit box.

⬢Screw the Z-screw covers onto both leadscrews.

Covers should be screwed fully to the motor, but not too tight! The motor must be able to spin freely!

Step 4 Z-axis: assembling the motors

⬢For the following step, please prepare:

⬢Z motor left (labeled Z axis left, shorter cable)

⬢Z motor right (labeled Z axis right, longer cable)

⬢M3x10 screw (8x)

See the second picture. The motor with the shorter cable (red arrow) is on the left, the motor with the longer cable (orange arrow) is on the right!

⬢ATTENTION: Motor cables must be oriented towards the frame! Adjust (rotate) the motor. There is a small cutout in the frame on the lower edge for each cable.

⬢Secure each motor with four M3x10 screws. Tighten evenly and carefully as you might break the printed parts.

Step 5 X-axis: trapezoidal nuts (part 1)

⬢For the following step, please prepare:

⬢Trapezoidal nut (2x)

⬢M3x18 screw (4x)

⬢M3n nut (4x)

⬢Turn the X-axis upside down and insert nuts into traps on both X-ends.

In case you can't press the nuts in, don't use excessive force. First, check that there isn't any obstacle in the nut trap.

Step 6 X-axis: trapezoidal nuts (part 2)

⬢Carefully rotate the X-axis onto its backside.

⬢Insert the trapezoidal nuts to each X-end.

Note the correct orientation of the trapezoidal motor nuts!

⬢Tighten the nuts with M3x18 screws.

You can use any of all four holes on the trapezoidal nuts.

Step 7 Assembling the X-axis and smooth rods

⬢Besides the X-axis, please prepare for the following step:

⬢Smooth rod 320 mm (2x)

WARNING: be very careful while installing the X-axis on the trapezoidal lead screws. The process should be smooth, otherwise you might damage the thread inside the plastic nut. Reseat the axis if necessary.

⬢Carefully slide the X-axis on the trapezoidal lead screws. By rotating both screws simultaneously let the X-axis slide until both trapezoidal lead screws are visible. If you feel any significant resistance, try to reseat the axis first.

⬢Make sure the top smooth rod of the X-axis and the lower edge of the frame are parallel.

⬢NOW, PLEASE BE VERY CAREFUL! Gently insert the remaining smooth rods through the bearings on the X-axis all the way down into printed parts, do not apply too much force and do not tilt the rod!

In case you manage to push out balls from the bearings, please count them. One or two balls are ok, if there are more of them, please consider ordering new bearings

Step 8 Placing the Z-axis-top parts (part 1)

⬢For the following steps, please prepare:

⬢Z-axis-top-left (1x)

⬢Z-axis-top-right (1x)

⬢M3x10 screw (4x)

Step 9 Placing the Z-axis-top parts (part 2)

⬢Place the Z-axis-top-left part on the rods and align it with the frame.

⬢Ensure the holes in the printed part are fully aligned with the holes on the frame.

⬢Use two M3x10 screws to tighten the Z-axis-top-left part.

Don't use excessive strength during tightening. In case of increased resistance, try to place the screws from the other side to "clean up" the hole. Then return to the front side.

⬢Repeat this step on the other side of the frame with Z-axis-top-right printed part.