Problem with Ekos Internal Guiding

[RichardNewbie]

Hi Star Gazers.

 

I hope someone may be able to help me.

 

For my full setup see end of post.

 

After some successful tests of guiding in the last month as I progress toward doing DSO imaging, it has just gone pear-shaped. I have been using Ekos internal guiding, pulse not ST4 using a QHY5L II camera.

 

In the past week the guiding process cannot keep within 2.5" for more than a minute, and within a couple it can be 40" out - RA is the main the problem. It does not always happen – just mostly.

 

In desperation, to avoid moving the guide camera, etc to another PC, I started using PHD2 on the Pi itself (after ‘disconnecting’ the camera from Kstars and ‘connecting’ to PHD2).

 

It works OK and the results are quite good - same INDI server, same guide scope, camera, mount - literally just changing from Ekos to Pi-based PHD2 within minutes solved the problem. When I set guiding on Ekos the next night, it again failed. I leave the mount connected to Ekos, but obviously not the camera.

 

I have tried another camera (ASI385) and using ST4 – no better.

 

I have checked that cables are not snagged, clutches are tight, and scopes are balanced and secure. Polar alignment is within 60” each time (as shown by Ekos Legacy PA function).

 

Obviously I can continue to use PHD2 on the Pi, but I would prefer the Ekos internal guiding system for unattended imaging (eventually!).

I attach a snip of the guiding screen when I had another try last night.

Hope all this is clear....

 

Setup:

 

HEQ5 Pro mount (10 months old)

Serial/usb adapter

INDI server running on Pi 4 8GB under Astroberry.

QHY 5L II guide camera.

Cheap 50mm finder scope as guide scope.

Kstars 3.3.4 desktop under W10 remotely

Ethernet connections to all

Mount (as Eqmod) and guide camera on INDI running on the Pi

.

  

 

[vineyard]

You're on a v old version of Kstars (unless that's a typo in "3.3.4"?)?  Have you tried using bin 2x2?

I've noticed a similar thing with the RA on my EKOS guiding v recently too (I'm on 3.5.4).  The RMS balloons out & RA is the culprit.  I actually switched to guiding via EqMod mount, and slightly bigger box size, w a guiding rate of 0.50 (I believe the higher the number the stronger the impulse so if you're at 0.9 maybe try reducing that).  I also found increasing my Exp time helped a bit but I see you're at 7s (I tend to stick to 1,1.5 or 2s so maybe try a little shorter)?

Those tweaks have helped me - I lost only 9 out of 202 lights last night to RA going awol, the rest were fine (RMS <1 quite a lot of the time).

You could also try posting the log on indilib.

Good luck!

 

[RichardNewbie]

Tks for this. Correct - my version is actually 3.5.4 as well. I will try these ideas the next clear night. I do guide using Eqmod - only used ST4 to see if it made any difference. It didn't.

 

 

 

[alacant]

Hi

Without the indi and guide logs, we can only guess.

A few ideas. Try 1 first.

• un-check the 'swap' box and try again using 2s guide exposures
• update the pi to the latest version of indi
• clear the calibration
• reset the guide parameters to default
• Using a step of around 900, perform a new calibration pointing south near the equator.

Cheers and HTH

Edited December 7, 2021 by alacant

[AstroMuni]

And if RA is always the culprit try the GPG guiding in Ekos which is meant for RA.

These are just default settings and you will need to update this depending on your mount.

[Rallemikken]

Guide module in Ekos is a little hit-and-miss. Struggling with it myself. When it works, it works very well, but on some nights I have to use PHD2 just to get things done. A matter of options, and for some reason, the options you succed with one night messes it all up the next. I have found a setup where i just change two parametres, Exp (1.5 or 2.0 seconds) and Bin (1x1 or 2x2). The rest is left to defaults. Always clear calibration (the red trashcan) when starting guiding, and don't touch the Swap checkbox. I belive Ekos ticks this itself if nesecarry during calibration. Box size 32. Guiding rate 0.500.

Is camera and guidescope given correct specs? And tick the two Corr checkboxes, that will give you a visual aid to what's going on.

Edited December 12, 2021 by Rallemikken

[wimvb]

It looks to me like the calibration is not valid anymore. A first step in trouble shooting should always be to clear the calibration and let the guider recalibrate. Also make sure that the guide scope focal length and camera pixel size are set correctly.

The internal guider works well for me, but I clear the calibration every imaging session. This is with a ZWO ASI290 guide camera, binned 2x2, and an OAG. I always let it calibrate near the target.

Edited December 12, 2021 by wimvb

[RichardNewbie]

Thanks everybody. Regret that none of the suggestions have worked. Recalibration has been done regularly each night as I switch from Ekos to PHD2 and back again, and change target object. I guess there is something in my setup that is causing the problem. I will persevere the next clear night. I will post again if I find a solution.

[RichardNewbie]

The solution!

It was the mount - a 10 month old HEQ5 with only a few hours use. I fitted a Rowan belt system and now get sub 1" range on Dec and RA using PHD2. I think the main problems were the RA backlash was very large and the RA worm drive end float nut was screwed up very tight -  both were sorted when the Rowan system was fitted. I also dismantled the mount and renewed the grease in the Dec and RA worm drives. Oddly, the was no grease on the HEQ5 spur gears.