Meridian Flip Failure after recentering


I’ve been using SGPro for a while now with great success. It does Meridian Flips pretty reliably too. However, sometimes it would fail. It does the Flip, Plate Solves fine. Then, it moves it to center exactly where it should be. Problem is, it jumps the gun to Plate Solve again while scope still moving. In many instances it would be able to Plate Solve on trailed stars, but in about 1 out of 3 cases it fails and tries to abort the Sequence. I usually intervene at this point to only resume it.
Seems to me like an easy bug to fix. Just introduce a 1-2 sec. pause between centering an platesolving.


It could be that the driver is reporting that the slew has finished before it has. If so that’s what needs to be fixed. Adding band aid fixes for an underlying problem is seldom a good idea.


It most likely reports slew end correctly. Could be just inertia of the Scope. It is pretty large and longish-focus. EdgeHD 14" at F/7.7. As I said originally, in many instances it works fine.


This field should do that:




Horia, I will definitely give a try. What’s the default setting for settling time? Thank you. Ian


Hi Ian,

the default – as coming from SGP – is zero. The actual minimum setting is very much mount dependent. As Chris already explained, some drivers enthusiastically report “slew completed” while the mount is still adjusting the final position. Another issue is that, after an eastward slew, there is a dead time when the scope is not tracking while the mount gear “consumes” the RA-backlash.

So, for a very high-quality mount, a couple of seconds should be OK. For a normal mount, 10 to 20 sec might be necessary. To be honest, I never tried to optimize that setting, given that it is only active during the target acquisition and after a meridian flip.



Thank you, Horia. I will certainly give it a try next time I’m at the scope.