07. Heated bed

Step 1

Heated bed type

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• 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.

Step 2

Heat bed cable check - MK2(S)

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• 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.

Step 3

Heated bed assembly - MK2(S)

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• 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.

Step 4

Heated bed assembly - MK2(S)

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• 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.

Step 5

Heat bed cable check - MK2(S)

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• 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.

Step 6

Next chapter

⌕

• Congratulations you have finished this chapter :)
• Go to the next chapter: 08. LCD screen and PSU.

Step 7

Repair step

⌕

• 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.

Step 8

Heat bed cable check - MK2.5(S)

⌕

• 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.

Step 9

Heated bed assembly - MK2.5(S)

⌕

• 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.

Step 10

Heated bed assembly - MK2.5(S)

⌕

• 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.

Step 11

Heat bed cable check - MK2.5(S)

⌕

• 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.

Step 12

Next chapter

⌕

• Congratulations you have finished this chapter :)
• Go to the next chapter: 08. LCD screen and PSU.

Step 13

Heated bed type

⌕

• 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.

Step 14

Heat bed cable check - MK3(S)

⌕

• 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.

Step 15

Prepare heated bed assembly - MK3(S)

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• 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.

Step 16

Heated bed assembly - MK3(S)

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• 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.

Step 17

Heated bed assembly - MK3(S)

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• 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.

Step 18

Heated bed assembly - MK3(S)

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• 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.

Step 19

Heat bed cable check - MK3(S)

⌕

• 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.

Step 20

Next chapter

⌕

• Congratulations you have finished this chapter :)
• Go to the next chapter: 08. LCD screen and PSU.