Drive Train Errors

Last night, was ideal conditions, clear, not too cold, still air. So I setup for a run at M42 with the C80ED. Leveled, powered up and aligned on Betelguese. I used liveview to align and focus. Slewed to M42 and waited for M42 to clear the roof. Then the problems started.

Every single frame was showing mount drive errors. I tried to adjust the scope in the rings, to shift the balance, errors. I powered down and realigned, errors. No matter what I did, I couldn't get rid of the drive errors. I spent some 1.5 hours faffing with it, trying to eliminate the errors. Even setting the camera to 15 seconds didn't work. So, with the cold working it's way between my toes and up my spine, I quit whilst I was behind, packed up and went to warm up.

A quick balance check during the day, today, and I shifted the balance, so that the scope with camera was a little tail heavy. The sky looking clear, I figured it was worth setting up for a bash. Of course, it's window tonight, and the clouds are scudding by. However, I still setup and aligned. Although I didn't bother with trying to align on M42. I just used Betelguese to sort out the drive errors. Even with the shifted balance, I was still seeing tracking errors, but this time, using a lantern I was able to see clearly and make better adjustments. By shifting the OTA backwards in the rings about 1" I was able to take shots up to 60 seconds, that didn't shot drive errors. Totally unusable, thanks to the clouds, and I was getting some star trails, that I think was caused by the gusty wind. After 30 minutes and a fair few test frames I'm confident that this has resolved the drive errors, so a productive night anyway, and I'm pleased with the results.