SGP and PODMAX dome issues

Sequence Generator
1

I have tried to use SGP in my observatory and really like many of the automation features and capabilities it provides over TheSkyX Pro. But there is one major problem I can’t seem to get around which makes it impossible to use for me.
It has to do with the dome control. I’m not sure where to go next so I am asking members of this forum for assistance.
My equipment consists of:

  1. A Skyshed POD MAX dome with automation (motor and electronics).
  2. Paramount ME II mount
  3. Astro-Tech 14” RC with a Skywatcher Esprit 80 Triplet piggybacked.

My problem is the dome will not track correctly under SGP. I use the ASCOM interface designed for the POD MAX dome. More specifically, when I start up the observatory, the telescope is in the home position. The dome is set to slave to the mount. The dome will move the slot in position where the Esprit 80 is centered. After that is when things go wrong.

When I start a sequence, the mount moves to the object and the dome moves as well. However at times, before a plate solve can be done, the dome moves in the opposite direction causing the Esprit 80 to be looking at the ceiling. Naturally the plate solve fails. I was able to get it to successfully plate solve and focus while imaging the California Nebula the other night.

Then the slot moves in the other direction, maybe 2 – 3 feet, and moves back again. This goes on about every minute. I call it the “Dome Watusi”. Finally during the imaging of the California Nebula, when the mount was near zenith, the dome was positioned the exact opposite direction of where it should be in order to get a clear view of zenith. The dome slot opens past zenith.

The POD MAX is a 12.5 foot diameter dome. That should put the radius at about 75 inches. The mount is on a pier that is dead center of the dome. I measure the distance from the mount pivot to the center of the Esprit 80 optical tube is 38”. Mount pivot point is 20 inches below the horizon of the slot opening.

My observatory settings in the equipment profile are:
Observatory type: Dome
Radius at Equator: 75
North Offset: 0
East Offset: 0
Vertical Offset: -20
GEM offset: 38
Update Frequency: 60
Allowable Error: 1
Slave on Sequence Start and Park Observatory With Mount are checked.

I have a link to the SGP log from the night I imaged the California Nebula and stopped because the scope was looking at the ceiling while pointing straight up.

https://www.dropbox.com/s/nhjvms5wu9ypdb1/sg_logfile_20200104173659.log?dl=0

BTW, this does not happen when TheSkyX Pro controls the dome. I know SGP uses TheSkyX Pro for mount control. Is there anyway do include dome control?

Any help out there would be appreciated. Are there any POD MAX owners running SGP who are happy with their setup?

2

Dale, did you ever get your PODMAX - SGP issue resolved?

3

Hi jimsarge,

I gave up on SGP controlling the dome and just let TheSkyX Pro handle it. TheSkyX works fine. This was also recommended by an astronomer at Kitt Peak National Observatory. They use SGP and TheSkyX Pro but let TheSkyX control the mount and the dome.

Dale

4

I can’t speak specifically about the PODMAX but we did address some slaving issues about a year or so ago. May be worth making sure SGP is updated and trying that.

Jared

5

Thanks Jared,

I am using version 3.2.0.660 and I am a subscriber. Should I update to the latest version 4? I assume I should stick with 32 bit since I don’t know about all the drivers I am using.

Dale

6

Thank you, Dale.

7

Dale,
3.2.0.660 should have the slaving changes I mentioned. If you’re still having issues with SGP slaving it may be worth providing an updated log so we can look.

Thanks,
Jared