Meridian Flip and pointing at the wrong part of the sky

Hi all - I’ve had a lot of really great success with the auto meridian flip, but for whatever reason when it flips from imaging in the east to west the flip points the telescope in a complete random portion of the sky and I’m not sure why this is the case?

When starting, the plate solve and auto center work great and it guides perfectly; however, when it’s time for the flip it will plate solve correctly, but when the flip happens it goes off to some other random location. Often times it ends up point right at the house and so it can’t recover.

When I clear our the the data from from EQMOD this will help for one night, maybe two, but then it gets out of sync again.

My target’s meridian flip is happening well after 1AM local time (9/14) so I’m already in bed. After the attempted flip it will just error out in recovery mode until it tells it to park. Up until that point things are going great tho. I’ve attached a photo to show how it parked call catty whampus (technical term) that is certainly not the home position (haha). AND here is a link to the log file from last night as well.

Any thoughts on what might be causing this to happen?


  • SW EQ6-R Pro
  • ES 127 ED APO w/ .7x FF/FR
  • ZWO ASI 1600 Pro Mono
  • SW 50mm Doublet Guidescope
  • ZWO ASI 120 mm guide camera
  • EQ MOD
  • SGP - latest release, but this was also happening every now and again with the last release as well.

Have you read the specific instructions on using eqmod with SGP? That is a good place to start. Failing that, abandon Eqmod and just use the regular Ascom driver. The author is an SGP user too and it worked fine with the synscan system on the Avalon.

Hi Buzz - thanks for following up! Yup yup, the SGP guide for EQMod was what got it working right in the first place but over time it seems to have become progressively less stable? It works sometimes and then not others… Do you happen to know the name of the ASCOM driver? The only I’ve seen is the simulator. Last night I went ahead and uninstalled EQMod and re-installed it and reapplied the settings to see if maybe this new instance will work properly.

I should also add that I bypass the synscan system entirely and just use a direct link the mount as opposed to the controller.

Is there a pointing model being built in EQMOD? This sounds like every time you solve and sync it is updating the pointing model and eventually it gets out of whack. This would explain why when you clear things out and start over it works for a few nights before getting worse and worse again. With plate solving pointing models really aren’t necessary at all. Is there a way to disable the pointing model (if this is indeed the problem)?

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@joelshort - that is what I’m thinking might be issue after looking it over, but I can’t seem to find a way to disable the pointing model from with in EQMod. Maybe I just need to clear it out every night before the session starts…

The driver I think is still on the Ascom website.

Just checked. Links back to SkyWatcher website. Driver is there.

@buzz thanks for this. I’ll go looking, appreciate it!

Had the same issue with my eq6 r pro. Proved that it was power issue. While doing meridian flip , the mount didn’t get enough juice to make the flip. It hanged for 2 or 3 seconds, continued slewing but it pointed nowhere near the target.

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In EQMod, clean out any pointing model, make sure you disable EQMod automatically loading a model from file, and set EQMod to “dialog based” rather than “sync”. That should solve any problems caused by the pointing model. You don’t need a pointing model anyway when using plate solve.

Hi all - thanks for the feedback. After reviewing my EQMod settings I had everything set properly with Dialog Based selected, but it still was apparently aggregating over time. For the time being I’m just going to ensure I clear it out every night before use as that seems to have fixed the problem till I switch away from EQMod.

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