A very simple rotary attachment for a laser engraver using standard reprap parts.
This uses two NEMA 17 motor wired in parallel. It is cut from 1/4" MDF.
The design is simple intentionally so it can be modified and changed to fit your need. I went with two motors so there is no belts or gears or extra stuff making it more complicated.
A little trick is if you resize the rollers on the threaded rod (either the printed or cut one) to match the same size as your gear pulley on your Y-Axis then you won't have to modify your steps to run the engraver. Mine was .85" in diameter.
2 NEMA 17 motors
2 5mm to 8mm couplers
2 8mm threaded rods about 8 inches long
4 F60ZZ Flanged bearings
(regular 608 bearings will work just fine but you will need a few extra M8 bolts)
12 M8 nuts
1 Wood glue