December 10, 2025
Description
Instead of hoping that the springs are the same stiffness and didn't buckle or that the belt wear is uneven, you can tension the belts manually to be right. This mod is a very simple yet effective method for adjusting the belt tension.
Do this at your own risk, too high tension risks shearing off the stepper shafts and accelerating wear of the belts.
2x M5x22mm BHCS
2x 8x8xM5 Heatset insert
4 walls
No supports
Print as oriented
Print out of low creep material, so no PLA and no PA
The stiffer the material the better
Remove original tensionners
Remove back panel held on by 8 M3 screws, being careful not to remove the poopchute and structural brace
Remove aux+case fan assembly
Remove the tensionners
Assemble manual tensionners
Install the heatset threaded inserts in the hole at the bottom
Remove the idler pulley and pin from the original tensionner and install them on the manual tensionner
Screw in the M5 screw until it hits the bottom of the tensionner (if you go too far it bulges out, but shouldn't affect the usability)
Install manual tensionners
Slip the belt onto the idler
Place the screw inside the frame
Push the tensionner in place
Screw in the screws until there is some resistance to screw further and unscrew them ¼ of a turn
adjust belt tension using the M5 screws (CCW to increase tension CW to decrease it)
Fasten the M3 washer screws
Reinstall the aux fan and back panel if you need them
(or don't if you only print pla and petg as they add noise and make for asymetric cooling)
Run Input shaper calibration
Submit feature requests here!
License:
Creative Commons — Attribution — Share Alike
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