Motor Focuser for Skywatcher Quattro & PDS Crayford

thingiverse

This is a motor fucuser to use with SkyWatcher Crayford focusers on Quattro and PDS series telescopes. The aim was to have a non-invasive focuser, 3D printed, cheap, INDI/ASCOM compatible, since I use it on my Quattro 300P with Astroberry. Also a USB powered only setup was favored. There are a bunch of inspirations which I linked as remix sources. Thanks guys for your awesome work! The fucuser is a simple "click&slide" mount; it will be clicked onto the focuser, leaving tensioning screws accessible; no modification or removal of the microfocuser knob is neccessary. Electronics are based on Arduino Nano (Clone), 28BYJ-48 geard stepper and ULN2003 driver breakout board. A DS18B20 temperature sensor is highly recommended. You can get all that on AliExpress for little money if you are patient. Software: https://github.com/fehlfarbe/arduino-motorfocus For compatibility with ASCOM/moonLite DRO driver, desolder the 10k capaciator on the bottom of the Arduino Nano according to this: https://www.astroscopic.com/blog/disable-arduinos-auto-reset-connection INDI-users do not need to do so, but even with removed capaciator, the focuser will work as expected on INDI. To set correct motor direction, please change within arduino-motorfocus.ino line 34 AccelStepper stepper(AccelStepper::FULL4WIRE, 6, 4, 5, 3, false); to AccelStepper stepper(AccelStepper::FULL4WIRE, 4, 6, 5, 3, false); (special thanks to fehlfarbe again for supporting me on this issue) The slide mechanism is based on two non-standard Allen key M3x80 screws, which have ~25 mm thread and ~55mm shaft. You can find them on ebay around €/$10,- for 4 pieces. (a M3 threaded rod or eben shorter screws will to the job, be a little creative) Use a M3 thumb screw or grub screw of your choice on the bottom to lock the mechanism. DIN 7991 M3 coutersunk can be used to attach the lid. A DIN 912 M3x6, 8 or so can be used in the focuser_attach. You probably need to cut M3 threads in the focuser_clip, motor_housing and focuser_attach. choose the correct version of your clip: SkyWatcher PDS: focuser_clip_PDS.stl SkyWatcher Quattro: focuser_clip_PDS.stl The PDS version is untested, since I do not own a model of this series. Please test it, feedback highly recommended. Special thanks to user fzappa for supporting me creating the PDS version. The thermal_probe_clip.stl attaches a sealed DS18B20 to the 9x50 finder of the Skywatcher Explorer and Quattro series telescopes. Please feel free to bear recommendations and change wishes. 2021.05.13: Modification of the PDS version to enable a more stable position of the clamp. focuser_clip_PDS_add_0.8mm.stl