DIY Radian Raptor Focuser

[JonCarleton]

This is a simple focuser using the NEMA17 stepper motor with the planetary gear, readily available on eBay (Part #36PA5.18G), a WaveShare 2 motor HAT for raspberry Pi, using only the motor 1 portion of the card (waveshare.com Part #15669) and a GT2 timing belt pulley set with belt with a 20 and 60 tooth pulley (also on eBay).  It runs on the Pi (as does my whole setup) under indiserver using the INDI indi_wmh_focuser driver in 64 bit Linux Mate v20.04.   It is possible some other WaveShare single motor HAT cards would work, but the indi_wmh_focuser driver was designed around this card, and I have used it before on my SkyWatcher 250P dobsonian with excellent results.

Total cost of equipment $57.00, plus a couple of spare pieces of aluminum and a couple of  nuts and bolts.  About 30 minutes of fiddling around on the lathe and mill for the bracket and the aluminum reducer insert for the large pulley (to convert to the Raptor fine adjustment shaft).

I get 50,000 steps full travel.

Edited May 31, 2021 by JonCarleton