Motor bracket for 2" Crayford telescope focuser

thingiverse

This is an adapter to attach a stepper motor to 2" Crayford telescope focuser (designed for my iOptron brand focuser, which seems to be identical to GSO brand focusers: https://agenaastro.com/gso-linear-bearing-rc-crayford-focuser.html ). It is attached to the coarse focusing knob on the left side. One also needs a 3mm thick metal stepper motor bracket ("NEMA 17 42mm" kind; something like this: https://www.amazon.ca/Chiloskit-Stepper-Mounting-Bracket-Fixing/dp/B07F8RLPBC ), and an appropriate motor shaft adapter. (My motor shaft diameter is 5mm, my focuser coarse axle diameter is 4mm, so I used a 4mm-5mm adapter.) The motor is attached directly to the axle (no belt involved). The metal bracket - 3d-printed bracket connection provides enough of wiggle room to fine-tune the alignment between the motor shaft and the focuser axle. To attach the adapter to the focuser, one needs to replace the four M3 screws with longer ones. To operate the motor, I use an Arduino based controller of my design ( https://pulsar124.fandom.com/wiki/Telescope_Focuser ), but you can use any open source project out there. I provide both the Autodesk Fusion file, and the STL file.