Gemini went awry tonight

[Joel Hatfield]

I'm not sure where to put this post because I don't really know if this is a Gemini or ACP problem. Two nights ago I ran a plan and it worked to perfection. It opened the roof and slewed to M76 and carried out my plan and plate solves worked great. At the end of the session it shut down actually due to a weather alert but that's ok. Tonight I go to run the same plan again but I see from inside the house the first plate solve fails. I go out to the observatory and the scope is pointing at the wall of the observatory. ????

It seems that the ra time is out by a little over four hours from it's correct position. I cleared the pointing model and synced on a star and it wanted to go off to somewhere way off for the next slew. One thing I notice is that the Gemini driver reports the opposite of what ACP sees when it states what side of the meridian it's pointing. This has got to be involved with the problem but I checked in ACP and Gemini and the time, location and date are correct.

I don't understand what would cause this. Posting the log will just say that the plate solve failed. I'm hoping someone using and MI-250 and Gemini can help here. I was just bragging about how everything for the first time went perfect two nights ago and now this.

[Joel Hatfield]

I just checked the time in RA on Gemini and at local sidereal time of 15:00 it should be 03:00 at due north right? Well pointing north I'm reading 20:50 at park so it's off by about 6+ hours. It seemed to do this on it's on since two days before. Any ideas?

[Bob Denny]

This is 99% certain to be a Gemini setup problem. I'm going to have to defer to someone who is a Gemini expert. Are you running the current Gemini ASCOM driver (from the ASCOM Telescope Drivers download area)?

[Bob Denny]

I can't put a picture together from what you're saying.

... the time in RA on Gemini and at local sidereal time of 15:00 it should be 03:00 at due north right?

I can't understand this, sorry.

[Dick Berg]

Bob, What Joel means is that if the LST is 15 hours (that's HA = 0h, on the south-facing meridian), then if the telescope is pointing north (and aimed below the pole), then that HA = 12h, and the RA is therefore 3 hours. His actual reading is RA = 20h 50m, so his readout is in error by 6h 10m.

[Joel Hatfield]

I changed the battery out on the Gemini, it was about 1.5 years old and tonight it would plate solve after an initial sync. Not sure if it was the battery but that's as good a guess as any at this point. It was just puzzling how two nights after a perfect run it did this.

I think one thing about the RA is if it's pointing towards Polaris then the RA lines are closer together so that may account for the difference but it seemed large to me. It hit the plate solves tonight and the RA/DEC readings were correct.

Thanks everyone, I'll keep an eye on it.

[Bob Denny]

Oh, I get it now! Sorry, I was so focused today on a huge change to ACP.exe (all of the ActiveX interfaces changed their GUIDs and member IDs, affecting Scheduler and a few other things)... I didn't devote enough brain power to Joel's message.

[Bob Denny]

OK, we'll call this a Gemini problem. I'll move the thread now.