How Do I Replace the Belts on an Ultimaker Printer?

Replacing Belts

Estimated Time: 1-2 Hours Difficulty: Difficult

 Tools Needed

• 2.0mm Allen Wrench

Materials Needed

• Replacement Ultimaker Belt (Belts for Ultimaker 2/2+/2E and Ultimaker 3/3E are different, so double check that you have the right part

1.) Checking Belt Condition 

• Belts stretch over time
• Belt teeth can be damaged if printer movement is jammed for some reason.
• Belt condition should be checked monthly.

1. Check belt tension by plucking the belt. It should make a sound like a bass guitar.
2. If not, try to square the axes (see Squaring the X/Y Axes [LINK])
3. If the belt is still loose after squaring it should be replaced.
4. Next, visually inspect the belts for damaged teeth. It is acceptable for belt teeth to have some wear on the edges, but if more than 20% of a tooth is missing the belt should be replaced.

2.) Replace the Belt 

1. First, turn off the machine.
2. Loosen the grub screws in the pulleys on the axle that is holding the sliding block attached to the belt you want to replace.
3. Slide the axle halfway out of the machine
   1. Remove the pulleys and spacers from the free end. NOTE - make sure to store them in a way that you will put them back on in the same order and orientation.
   2. Loosen the grub screws on the axles holding the belt you are replacing. NOTE - You should be loosening 6-7 pulleys in total.
   3. Slide the axles out of the machine far enough that you will be able to remove the old belt.
   4. Slide the old block off the axle
   5. Replace it with the new one
   6. Fit the new belt over the pulleys.
   7. Replace the pulley and spacer on the axle holding the sliding block
   8. Slide the axels back into the frame off the machine.

You will now need to re-square the axes, so continue with Squaring the X/Y Axes [LINK].