Hello, everyone! Hopefully this is the proper spot to put this post.
I finally got my telescope out the past couple nights to take advantage of some clear, smoke-free skies for a change. I'm also testing out a new focuser I built based on the MyFocuserPro2 open-source project. Unfortunately, I'm running into some issues that I hope someone can help with.
It appears the focuser is skipping steps during the autofocus routine. This is causing some major issues with focusing. The V-curve isn't as accurate as it should be, and when the focuser moves to a particular position it may not line up with where the ideal focus position really should be. I've had some really poor focus attempts, but also some good ones, so it's hit-and-miss as to whether it works correctly or not. It seems to be dropping steps when moving inward, fighting gravity and pulling the camera and draw tube into the scope.
Based on the parts I purchased, I think these are the pertinent details for this build to provide some insight into what's going on:
- Microcontroller: Arduino Nano (generic)
- Stepper Driver: BTT TMC2209
- Stepper Motor: NEMA 14 (0.9deg/step), coupled to the 10:1 focuser shaft
- Motor current: 400mA, per the motor specs, defined in software, coil power always enabled
- Step size: 1 (no microstepping)
- Scope: Astro-Tech AT60ED w/ 0.8x FF/FR
- Camera: ASI1600MM-Cool
If there's anything else that might help, I'm happy to put it here. Let me know. Thanks in advance for any help anyone can offer.