Belt Adjustment

There are three belts to be adjusted on your Solidoodle. These steps will guide you through adjusted all three of them.


  • 2.5 mm hex driver
  • 1.5 mm hex driver


  1. As always, before trying to work on any part of your Solidoodle, make sure that both the bed and extruder are turned off to prevent burns. Lowering the bed will also keep it out of the way so that you can access all the necessary parts more easily.
  2. To test the belts, you need to be able to move the belts. This requires the motors to be turned off. Go to the Manual Control tab in Repetier Host and click the stop motors button. You should now be able to move the extruder around without much resistance.
  3. Pull the extruder forward and out of your way.
  4. Using the 2.5 mm hex driver, loosen the four (4) screws on the left side of your printer. This will allow the y motor to move up and down. Note that you do not need to completely remove these screws as there is no need to remove this motor from the printer.
  5. Using your hand, lift the y motor enough to take the short loop of belt off the pulley attached to the motor. This belt is the source of most trouble with printing circles. If this is the only belt you wish to adjust, you can skip to step 11.
  6. Loosen the screws on the inside of the pulleys on the left and right end of the back horizontal rod using your 1.5 mm hex driver.
  7. Make sure the back horizontal rod is centered by feeling the bearings that hold it on either side of the printer. You want to make sure it is even.
  8. Push the extruder back and forwards. This movement should naturally align the belts, so that the back rod should not be moving side to side.
  9. Once the belts are aligned, you can tighten the pulleys again with the 1.5 mm hex driver. The screws should be tight enough to hold on to the rod, but be careful not to strip the screws.
  10. Put the short loop of belt back on the y motor pulley by again lifting the motor up.
  11. Make sure the two pulleys that the short loop of belt is on are aligned. If they are not, you can loosen the screw on the pulley on the back rod and carefully nudge it into place. Once it is aligned with the pulley on the y motor, tighten the screw.
  12. Push the y motor down firmly to draw the belt taut, and tighten the screws on the left side of the printer one-by-one to hold the motor in place.
  13. Check that you can move the extruder back and forth. It may be a little resistant.
  14. Slide the extruder forward so you can check the tension of the bottom belts behind the y carriages. These belts should be not too tight but not too loose. The most important thing is that they are of roughly equal tension.
  15. You can tighten or loosen the bottom belts by adjusting the screw on the back of the y carriages with a 2.5 mm hex driver.
  16. Now slide the extruder back to check the tension of the bottom belts in front of the y carriages. Again, these belts should be not too tight and not too loose. Using a 2.5 mm hex driver on the screws on the front of the y carriages, adjust the belts so that they are of roughly equal tension.
  17. If the belts are still not moving smoothly, there may be a problem with the pulley alignment on the back horizontal rod. Using your 1.5 mm hex driver, loosen the screw on the pulleys so that you can move them into alignment, then tighten to hold them in place. This step can take some trial and error until you get everything properly aligned.

Binding, an example issue

Belt issues may present themselves as "binding" - here is a video of user experiencing issues with the Y-Axis.

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