×

INDI Library v2.0.7 is Released (01 Apr 2024)

Bi-monthly release with minor bug fixes and improvements

RA limits and Meridian Flip on AVX

  • Posts: 76
  • Thank you received: 5
I have a Newtonian telescope and with all of the camera equipment near the front of the scope, i need to slide it back. This has caused problems. The back of the scope can hit the legs when pointing around the zenith. So I’ve had to go in and change my RA limits. I adjusted them from -20 to -5 both east and west. This has stopped the first issue, but I now have issues with a dead space I can’t seem to image.

There seems to be an area of sky I can’t slew to. If I try, EKOS will try and slew but the scope hits the -5 degree limit and stops. There seems to be no way to force a meridian flip. When I go into Ekos, i’ve tried to adjust the flip settings. But nothing seems to work. There seems to be no way to force the mount (AVX) to flip?

Is there any way to avoid this?

Thanks
Kevin
3 years 6 months ago #60705

Please Log in or Create an account to join the conversation.

  • Posts: 554
  • Thank you received: 138
Do I understand that there is a zone of the sky close to the meridian which your mount cannot enter because the scope will hit the tripod?

You avoid this area by setting the mount Ra axis limits to -5 degrees rather than the default of +20 degrees. This means that the mount will stop tracking 20 minutes before the scope reaches the meridian, at an hour angle of -20 minutes. You then need to wait 40 minutes, until the target is at an hour angle of +20 minutes before a slew to that position works.

If that's correct, that there is a zone close to the meridian which the scope cannot enter, then at present I don't think that Ekos will cope.
There are properties that would help but the underlying code doesn't support it.

The Ha Limit needs to be set so that Ekos stops tracking before the mount hits it's internal stop so this needs to be set to -6 degrees.
The Flip limit needs to be set to a position where the mount can move to the position safely, so this needs to be set to +6 degrees.

In practice the mount will then track to the -6 degree Ha limit and stop. That's where it remains because the scope hour angle, which is used to determine when the flip is done stops changing. what's needed is that in this case the hour angle used changes to being the hour ange of the target and when that is reached, in 48 minutes, the flip will be done, tracking will be restarted and the system can contiune.

It looks as if all that's needed is for the flip management system to change to using the target position rather than the scope position. Maybe only when he Ra limit has been reached. The trouble is that this section of code and the various state machines that manage it are so complex that chaning it is difficult and it is easy for it to break something else.
3 years 6 months ago #60709

Please Log in or Create an account to join the conversation.

Time to create page: 0.458 seconds