Motor Coupler Set 3mm-8mm (6 PCS)

These couplers replace the helical-cut aluminum flexible shaft coupler that came with the original Pegasus Astro Focus Cube (version 1). I found that the original coupler was contributing significant backlash to the focuser movements. The solid coupler I replaced it with fixes that problem, yielding near-perfect V-curves. HOWEVER: This set is exclusively metric, and some focuser shafts are Imperial, like those from Optec / Starlight Instruments. In my case, I had to drill out the hole so that the coupler would fit snugly on a 1/4" focuser shaft. This was easy enough to do accurately with a drill press but would be difficult to do with a hand drill. This set would benefit from having a few common Imperial sizes, orif the shaft size is known, the ability to order just one coupler of the size actually needed instead of a whole set, only one of which will ever be used.