07. Heated bed

This chapter contains the assembly guide for the 3 heated bed of Prusa MK2(S), MK2.5(S) and MK3(S).

Go to the step corresponding to your Prusa heated bed type:

Prusa MK2(S): continue to the next step.

Prusa MK2.5(S): go to step 8.

Prusa MK3(S): go to step 14.

On your heated bed, verify that the thermistor cable is not stretched, it should make a small curve.

If the cable is stretched it might move the thermistor from its position or damage the wires during printing.

Remove the two temporary hex nuts from the Y carriage and save them for later use. Keep the M3x12 screws of the y_belt_holder in place.

Place the heated bed on the Y carriage.

Be careful with the extruder during this step, it will slide when you rotate the printer to access screws under the heated bed.

Take 4x M3x8 button head screws (reused from your Original Prusa) and secure the heated bed in the corners. Do not fully tighten the screws yet.

Using the 2x M3x12 screws, secure the y_belt_holder to the bed. Do not fully tighten the screws yet.

Fully tighten all the screws evenly, incrementally and in turn, in this precise orders (do not use excessive force or you might break the spacers):

1st the screws of y_belt_holder.

2nd one of the corner in diagonal.

3rd the other corner in diagonal.

Repeat until all screws are fully tightened.

Verify again, that the thermistor cable is not stretched (it should make a small curve) and does not sag down too much as it could be damaged with bed movements.

Congratulations you have finished this chapter :)

Go to the next chapter: 08. LCD screen and PSU.

The next steps are for MK2.5(S) heated bed only.

Go to the step corresponding to your Prusa heated bed type:

Prusa MK2(S): go to step 2.

Prusa MK2.5(S): continue to the next step.

Prusa MK3(S): go to step 14.

On your heated bed, verify that the thermistor cable is not stretched, it should make a small curve.

If the cable is stretched it might move the thermistor from its position or damage the wires during printing.

Remove the two temporary hex nuts from the Y carriage. Keep the M3x12 screws of the y_belt_holder in place.

Place the heated bed on the Y carriage.

Be careful with the extruder during this step, it will slide when you rotate the printer to access screws under the heated bed.

Take 4x M3x8 button head screws (reused from your Original Prusa) and secure the heated bed in the corners. Do not fully tighten the screws yet.

Using the 2x M3x12 screws, secure the y_belt_holder to the bed. Do not fully tighten the screws yet.

Fully tighten all the screws evenly, incrementally and in turn, in this precise orders (do not use excessive force or you might break the spacers):

1st the screws of y_belt_holder.

2nd one of the corner in diagonal.

3rd the other corner in diagonal.

Repeat until all screws are fully tightened.

Verify again, that the thermistor cable is not stretched (it should make a small curve) and does not sag down too much as it could be damaged with bed movements.

Congratulations you have finished this chapter :)

Go to the next chapter: 08. LCD screen and PSU.

The next steps are for MK3(S) heated bed only.

Go to the step corresponding to your Prusa heated bed type:

Prusa MK2(S): go to step 2.

Prusa MK2.5(S): go to step 8.

Prusa MK3(S): continue to the next step.

On your heated bed, verify that the thermistor cable is not stretched, it should make a small curve.

If the cable is stretched it might move the thermistor from its position or damage the wires during printing.

Prepare the following hardware:

9x M3x12 or M3x14 flat head screws (reused from your Original Prusa).

9x spacers 5.5x6x3 (reused from your Original Prusa).

1x 2mm Allen key.

Move the Y carriage to the front.

Locate the center hole of the Y carriage.

Place 1x spacer on the hole of the Y carriage.

Take your heated bed and insert the hex key in the centeral hole.

Place the heated bed with the hex key on the Y carriage. Align the bed with the spacer and the centeral hole of the Y carriage using the hex key.

Add one of the M3 flat head screws and secure the bed in the centre. Do not fully tighten the screw yet.

From the right of the bed (or left if you are left-handed), insert a second spacer between the Y carriage and the heated bed. Use needle nosed pliers to make the insertion easier.

Use the 2mm hex key to align the spacer.

Secure the bed and spacer using one of the M3 flat head screws. Do not tighten fully yet.

Continue with the 7 other points of the heated bed.

Make sure no screw is fully tightened or you may warp the heated bed.

Fully tighten the M3 flat head screws evenly and incrementally in this precise order:

1st center screw.

2nd corner screws.

3rd side screws.

Repeat until all screws are fully tightened.

Verify again that the thermistor cable is not stretched (it should make a small curve) and does not sag down too much as it could be damaged with bed movements.

Congratulations you have finished this chapter :)

Go to the next chapter: 08. LCD screen and PSU.