4 replies to this topic

[skirider]

Hi Guys, Going nuts with the DIY OnStep mount I built, it has been physically working, and being new to both automated GEM and EKOS/KStars echo system, I can't make heads or tails of what going on, chatgpt has failed to help as well.

Basically, last week, the mount was pretty much going both east and west pier just fine but when I would navigate to a target, it would seem to behave as if some motor had to be swapped in terms of direction. The DEC sometimes seemed opposite and I started playing with various settings in INDI/EKOS.

Now, I am totally flustered as the mount stays stuck on one pier. Here is what I am doing.

1) Make it totally vertical (telescope up weights down, RA towards polaris), although no weights as this is strain wave drive, but the same position.
2) Try and Sync to Polaris.


When I try and sync to Polaris

[ERROR] OnStep slew/syncError: Outside limits: Max/Min Dec, Under Pole Limit, Meridian Limit, Sync attempted to wrong pier side.

I was under the impression that sync will swap the pier when I tell it that you are looking at Polaris at home position and everything will sync from here, but I am at a loss as to what is going on.

 

Any thoughts as a complete noob, I am sure I am doing something wrong here


 

[graukatze]

Make sure the time / location in EKOS is set correctly to where you are. I had funky behavior b/c Ekos was not automatically setting this right.

[skirider]

Ok that really helped and got me moving

1) I was using astroberry in hotspot mode so its time was wonky, it couldn't sync to internet.
2) while playing the mount went all over, sometimes during tests, only the Microcontroller was turned on, not the actual motors, so it thought it was where it was not, so I was getting OnStep errors.
2a) I am such a noob that I didn't know, under "Site Management" in INDI control panel, there is a button called "At Home (Reset)" that was all that was needed to tell it you are home now, you aren't breaching any limits.
3) This is a big one, DEC motor was in opposite direction, telling it to reverse direction fixed the remaining problems.

Right now its daylight where I am, but with mounting my Phone on the mount (instead of telscope) and the SkEye app showing where its pointed. I tested, and as precise as SkEye is, now the mount is navigating where its supposed to.
 

[Overtime]

Are you using a phone/tablet/app? If using some apps the info from the device will transfer nut some handsets can sometimes be a bit tricky and have to have some of the info changed every time it's reset. You could have ap and pm wrong, or maybe the time. Some devices work on a 24 hour time and not 12 hour. Another thing might be the northern/southern hemisphere setting. I am no expert on this, just repeating what people suggested I check when I couldn't get my go-to to work properly.

[Cliff Hipsher]

 

Hi Guys, Going nuts with the DIY OnStep mount I built, it has been physically working, and being new to both automated GEM and EKOS/KStars echo system, I can't make heads or tails of what going on, chatgpt has failed to help as well.

Basically, last week, the mount was pretty much going both east and west pier just fine but when I would navigate to a target, it would seem to behave as if some motor had to be swapped in terms of direction. The DEC sometimes seemed opposite and I started playing with various settings in INDI/EKOS.

Now, I am totally flustered as the mount stays stuck on one pier. Here is what I am doing.

1) Make it totally vertical (telescope up weights down, RA towards polaris), although no weights as this is strain wave drive, but the same position.
2) Try and Sync to Polaris.


When I try and sync to Polaris

[ERROR] OnStep slew/syncError: Outside limits: Max/Min Dec, Under Pole Limit, Meridian Limit, Sync attempted to wrong pier side.

I was under the impression that sync will swap the pier when I tell it that you are looking at Polaris at home position and everything will sync from here, but I am at a loss as to what is going on.

 

Any thoughts as a complete noob, I am sure I am doing something wrong here


 

Step #2 is totally wrong. You DO NOT sync the mount to Polaris.  Polaris is a circumpolar object that "orbits" around the North Celestial Pole which just happens to be the point in space defined by the Earth's axis of rotation.

 

What you need to do is use Ekos to run a polar alignment which entails slewing the mount, plate solving to calculate alignment errors, making mechanical adjustments to the mount in Azimuth and Elevation, rinse and repeat until the mount is pointing directly at the North Celestial Pole.

 

When the Polar Alignment is completed you can do a star alignment to refine the mount controller's pointing model.

 

HINT:  Polar Alignment impacts TRACKING and Star Alignment impacts Go-To accuracy.

 

2 key points:

 

1.  The mount MUST be pointing TRUE NORTH, not Magnetic North.

2.  (And this will be debated until the Sun burns out) The mount must be level.  I am of the opinion that close only counts in Horseshoes.