Spring-loaded NEMA 17 steppers / belt tensioner

thingiverse

This design features an additional spring attached to a screw for precise and secure belt tensioning. Adjust the screw until the belt "twangs" as desired. Additionally, it includes slightly thinner plates that allow the motor mounting screws to reach the bottom of the stepper holes before fixing it completely onto the plywood, eliminating the need for washers. The design also incorporates a sliding motor plate secured with four 25mm M3 screws and two nuts and washers, allowing the stepper motor to slide freely along the plywood wall. The tensioning screw holds a 10mm M3 spring and two M3 washers on each side, preventing damage to the plastic in the long term. To compensate for belt length variations during printing, the stepper is kept slightly loose by using 25mm M3 screws and nuts, with the option of adding washers if needed. After one month of use, no negative impact on print quality has been observed.