Laser rotary

This rotary isn't for the stock K40 controller such as the M2nano. You will need to upgrade to a controller that can be configured for a rotary device. I use a Cohesion3D running Smoothieware and Lightburn Laser software. You will need to modify the steps per degree configuration value for correct rotary length movement. Other laser controllers such as Ruida will work also.

Video https://youtu.be/c_CwmfQNdzA

parts required 5/16x18 threaded rod (or 8mm) four 608-2rs skate bearings small m3 nuts and bolts to attach pulleys and stepper motor six 5/16x18 lock nuts (or 8mm) Nema17 stepper motor HTD3 belt 105tooth 315mm length 9mm wide Gates Part# HTD3M-315 Four 30mm inside diameter rubber O-rings

I used the openscad parametric pulley to design the idler and HTD3 pulleys https://www.thingiverse.com/thing:16627

You can use any type belt that is approximately 315mm length and create matching pulleys. I used HTD3 type belt since that was found in my junk bin. Pulleys are 32 tooth. The stepper motor has mounting slots for tensioning the belt. If your belt is longer or shorter, just change the tooth amount to fit and re-print. Same with the idler pulley. If your O-ring is different size, make a idler to fit. You may want to experiment with using 2:1 reduction for more torque/resolution. 17 and 34 tooth pulleys are available for download.

If you want to laser tapered objects, print a pair of larger diameter idler pulleys. Adjust along the length of the threaded rod so the object is parallel to laser head.

The 5/16 threaded rod is slightly smaller diameter than the 8mm ID bearing. Wrap a couple of layers of tape around the threaded rod so the bearing fits tightly. Better yet, use 8mm threaded rod and lock nuts. You will need to modify the pulley/idler shaft diameter for 8mm. Get straight threaded rod to minimize wobble. You may need to add a washer between the bearing and pulley for more clearance.

The solidworks design files for the base is available if you want to re-mix. Fusion360 can import them for modification. The bearing pockets are 100mm apart. For really small diameter items, move them closer and use a shorter belt. You can purchase various size belts on ebay for a couple dollars. GT belts are common. 3mm and higher pitch pulleys are easier to print.

If you require a low profile rotary that works better for smaller K40 type lasers, https://www.thingiverse.com/thing:3068792