Check tension of short belts

Maintaining proper tension on the short belts is important to ensure good print quality. The short belts transfer the movements of the X and Y motors to the print head. If the belts are too loose, the movements of the print head and the dimensions of the final print may not be accurate.

Over time, the belts may become loose. It is recommended to check the tension of the short belts at least once every three months.

Using your finger, pluck the two short belts to check their tension. They should slightly resonate, like a guitar string. It should not be possible to press the belt against itself. Furthermore, the tension of the two belts should be equal.

Example belt too loose
Belt too loose
Example good belt tension
Good belt tension

To restore tension, perform the following steps:

Restoring short belt tension

1. Loosen the Y motor

  • Use a hex screwdriver to loosen the four bolts that hold the Y motor to the left panel.
  • Do not remove the bolts---loosen them enough so that the motor can slide up and down.

2. Press down on the motor

  • Firmly press down on the motor with one hand. This ensures maximum tension on the short belt.

3. Re-tighten the bolts

  • While still pressing the motor down, tighten the four bolts of the Y motor in a cross pattern.
  • First tighten the top-left bolt, then the bottom-right, then the bottom-left and end with the top-right. This ensures that the motor is attached straight.

4. Repeat for the X motor

  • Repeat the steps above for the X motor that is attached to the back panel.
  • Afterwards, check the tension of both belts again.

Loosen bolts Y motor
Push down Y motor
Tighten bolts Y motor