Filterwheel motorization by pludov

Last crawled date: 3 years ago

Motorisation of a basic 1.25" filterwheel, using cheap 28BYJ48 stepper motor and hall sensor for precise positionment.
Designed to be printed in PLA. There is a gear for reduction to the already reduced stepper, so it is really precise. Using a stepper allows to not use any current when the wheel is at its target position.
The whole thing is driven by an arduino Nano, connected to the filterwheel using a RJ45 cable.
This requires drilling two 3mm holes for fixation, and gluing a big wheel around the filters. Make sure you have the exact same filterwheel... Otherwise, the openscad file is provided so you can adjust it.
There is a ball in the filterwheel to make it hold its position. This ball must be removed.
Appart from the printed parts, the BOM is :
28BYJ48 stepper motor with its controller (~3€)
One US5881LUA hall sensor with a magnet - 2€ at MC Hobby
An Arduino Nano board
RJ45 connectors and cables
The filterwheel I used appears with different names. (at least here )
I also built an ASCOM driver that allow using the filterwheel from most astro software under windows.
Schematics & more details are available here (french only) :
http://pludov.blogspot.fr/2016/08/roue-filtre-motorisee-la-mecanique.html
Source code for the Ascom driver is on github