Hi All,

I need to stop tracking a few degrees west of the north azimuth (scope on the west side of pier, counterweight on the east and the scope pointing north). I think I set the under pole to a positive number (say 175) to stop it tracking 5 degrees west of the northern azimuth. 

Since getting a larger diameter scope in my dinky observatory, I can't track to the meridian for objects in the north without the scope colliding with the roof motor west of the north azimuth. I'm assuming if I set the under pole correctly, the mount will stop, wait for the object to pass the meridian then flip as normal. 

I can leave the meridian limit west as is because there is no risk of a collision. 

Thanks

Gary.

Hi Gary,

When tracking under the pole, the mount tracks from west to east.  So setting the est under pole limit to +175, the mount will react to the limit as you want.  Be sure to not check the auto flip on track, that way the mount will stop at 5 degrees west under the pole.  However be warned that if the mount stops there, that if you command a slew toward the east, it might hit your structure.

You assumption that it will stop, then flip is wrong.  It will stop, and stay there.  It will do a flip only if you command to go to a target on the other side.

Don W

Hi Don,

Thanks for confirming. For the flip, I meant when it was commanded by N.I.N.A to do so. I don't think I need to change the other timing settings.

The other thing I can do is use a horizon file to be more precise on limits. Right now I just set an altitude limit.

I may also install another magnetic switch in the control system and modify my scripts as added safeguard.

Gary.
   

Hi Gary,

Yes a horizon file that keeps your mount from hitting you structure is definitely needed.

Don W

Hi Don,

I've been testing the settings and the mount is not behaving as expected. 

I've conservatively set the Under Pole as per the attached. The mount continues to track to the meridian and then stops seemingly ignoring the 5 degree margin.

Not sure where the problem is so hope you can give me some pointers. 

Thanks

Gary.


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Hi Gary,

It sounds like you are tracking a star Over the pole, where the limit is set at zero.  The Under Pole ONLY applies to targets "Under the Pole".

Don W

Thanks Don, I'll try fiddling with that setting tomorrow. It make obvious sense now you mention it. 

It's a pity there also isn't a simple way to to prevent the scope approaching the meridian regardless of the object coordinates, The overlap setting doesn't allow a negative number. 

Cheers

Gary.