AZ-GTi : issue in DEC guiding - Forums

Topic starter

May 28, 2021

Dear astro-friends,

I ran yesterday on an issue while setting up my ASIAIR Pro to send guiding "pulses" to a new AZ-GTi I've recently bought from 2nd-hand. Despite many attempts with different settings in the ASIAIR App (DEC sets to Auto, South, North), I wasn't able to achieve DEC calibration nor guiding and could only rely on a good polar alignement and turn off DEC corrections to get round stars on 180’’ single frame.

Here is my setup :
76EDPH + Nikon D5500 + ASIAIR Pro + ASI120MM Mini + 30mm guidescope
AZ-GTi (v3.26A) connected through specific EQDir cable, fully supported by ASIAIR app latest version.

Except guiding in DEC, all features worked very well (polar align, focus aid, go-to function, meridian flip, auto centering target, dithering, home position) and send me to a new era of automatized AP session ;-) I really like this grab'n'go mount.

So, any though on that matter regarding DEC axis? I’ve read some posts on CN about that, but seems to be quite aleatoric from one user to others… It’s a little bit annoying as I’ve bought this mount to benefit from tracking and guiding on both axis comparing to my iOptron SkyGuider Pro who has RA only.

My next steps before going to an asylum :
- Downgrade firmware back to 3.20 as some users reported autoguiding on both axis with this old version?
- Double-check all settings in SynScan Pro and ASIAIR app I could have missed
- Double-check calibration settings in ASIAIR app. Any suggestion from experienced astrophotographers would be appreciated ;-)
- Balancing my equipment (4.5 kg in total) in DEC : does it play a role during guiding calibration that isn’t an issue at all while using just go-to command?
- What else?

Any help would be sincerely very welcome!

Christophe

Luis Marco Gutierrez

May 29, 2021

Always check the clutch to be engaged but not over tighten.

Christophe Perroud

Topic starter

May 31, 2021

Always check the clutch to be engaged but not over tighten.

Hi Luis, good point on this ;-) but as the mount slews fawless to any target, I don't think the issue could be here. CS, Christophe

Christophe Perroud

Topic starter

May 31, 2021

The az gti EQ firmware could be the problem. I had to downgrade to an older version

Thanks Allan for pointing out this firmware questioning, as readed on CN too. I downgraded to 3.20 and did some tests on saturday. Calibration worked on both axis, but guiding was a bit "olé-olé" due to wind blasts that night

I will try again soon, and maybe improve the backlash of this little mount (tutorial on YT). CS, Christophe

Jesco

May 31, 2021

The AZ-GTI can have quite big gear backlash in DEC, depending on the unit that you have. It's a bit hit'n'miss.

I had one for a while and got it to guide okay in DEC despite the backlash. I used PHD2 and increased the pulse length for each calibration step, reduced the number of calibration points, only ran North or South guiding to avoid direction reversal and - most importantly - tried to clear the backlash before starting a calibration. The south movement during calibration failed often, but PHD2 can guide regardless. Once I had a good calibration I saved it and reused it to avoid having to recalibrate (very comfortable feature!).

By clearing the backlash I mean that if the mount had last slewed to the south direction I moved it north manually to make the gear engage again. Calibration starts with north movement. If possible, I tried to approach all targets from the south direction.

Maybe this helps.

Helpful Respectful Engaging Supportive

Andy Evans

Jun 17, 2021

I had the same issue, using ASIAIR Pro, after adjusting backlash, down grading the software on the mount etc. I still had the same issue.

After reading up on PHD2 Guiding I increased the Calibration Steps from 2000 to 3500 and it starting guiding in Dec.

My take away was the pulses sent were not enough to compensate for any deviation in gearing etc, but all good now.

Helpful Concise

Christophe Perroud

Topic starter

Jun 19, 2021

Hi all,
After a couple of clear and windless nights I was able to do a few tests and get some decent results with this little mount. I first downgraded to 3.20 and pay great attention while balancing the payload. Then I played with all settings in the AAP guiding interface and could regularly stay between 0.9'' and 2.1'' RMS total. I didn't fix the backlash on the RA axis yet but still plan to work on it this summer :-) maybe it will help a little...

Below are some screenshots I took during those four nights.

Christophe

June 10th - 120'' subs : no dithering

10th June : 120'' subs - Dithering on RA + DEC. Probably the lowest RMS so far...

June 11th - 120'' subs : Dithering on RA + DEC.

June 14th - 120'' subs : Dithering only in RA...DEC curve has been kicked out somewhere after the whole night of shooting.

Helpful Engaging Supportive

cevoner

Jul 27, 2021

Hi, So did you conclude that PHD2 guiding helped to get the round stars you were after? Do you get >120 subs now? I also am having a guiding issue in that RA/DEC does not move in EQ mode. Did the downgrade to V3.20 firmware help? I just did that for my next test.
I also have the Skyguider Pro and was thinking a Goto mount would speed the night along.
It slews fine and gets the object in view but I can't get more than a 60 sec sub without trails.
I will try in ALT/AZ mode to see if will track that way. The moon holds for a while but that is a huge object.

Are you getting a fine polar alignment? And with what? I cannot see Polaris as it is obstructed by trees.
I have better luck in the fall as the leaves are gone. I had fine polar alignment for Skyguider Pro with IPolar.
You are right this is frustrating since I get very few clear nights here. Any further tips you have would be appreciated.
Could backlash cause the guiding issue? I have not had PHD2 work for me yet because I think it should give me
60 sec with rough alignment. It did complain when I tried to use it.

yashiro

Aug 8, 2021

New firmware 3.31 is now available. The release note says:

AZ-GTi motor controller firmware version 3.31:
Version 3.31
1. Improve Freedom Find accuracy.
2. Smoothier slewing for tracking satellites with Luminos app on iOS device.
3. Solve declination axis run-away issue while using 3-party applications for autoguiding.

Helpful

yashiro

Aug 12, 2021

3.32 is relased.

AZ-GTi motor controller firmware version 3.32:
Version 3.32:
1. Adjust maximum slewing speed automatically.
2. Try to solve declination axis run-away issue while using 3rd party application for autoguiding.

Christophe Perroud

Topic starter

Aug 13, 2021

Thanks Yashiro for pointing out new FW releases. Still a bit confused about "solve dec axis run-away" in 3.31 and "try to solve dec axis run-away" in 3.32...

By the way, I've just opened my mount for maintenance and little improvement works (RA backlash) as seen on YouTube. Looks like the guiding perfomance gets benefit from that during last try.

Next step will be FW update to 3.32...maybe

any feedback from AZ-GTi users around here?

Clear skies,
Christophe

cevoner

Aug 13, 2021

Yes, thanks for the updates. I have not tried the new firmware yet. Not a clear night here lately but I will be attempting a new process .
I'm moving to ASIAir and hoping for better alignment and guiding.

Anthony168

Aug 17, 2021

Yes, I encountered DEC problem too. Not just for guiding but when manually control the DEC movement in my asiair pro. When I'm not using full speed to control, it will only pointing downward… But once I adjust full speed. It will moving up again. I just downgrade the firmware to 3.22 but still not yet test it.

cevoner

Oct 13, 2021

I just added the latest firmware (3.36) and now using it with ASIAIR Plus. Guiding has been better but not great. I think if I can
actually do a more precise polar alignment I'll be good. My numbers are 1-2 rms with not so great polar alignment.
DEC still goes wild at times.
I can't see polaris as its' blocked by trees. I'm waiting for the leaves to fall. I have better success in the winter. I managed decent 120 sec
subs with ASIAIR Plus.

Christophe Perroud

Topic starter

Oct 14, 2021

Hi folks,
I've been facing lately big issue while trying to connect my AZ-GTi through FTDI cable. This problem has occurred just after the AA app (iOS) upgraded to v1.7… So, I've uploaded firmware 3.32 but no change happened. Downgraded to 3.20 and still having no connection at all. Thanks @cevoner for pointing out that there is a new firmware for this mount! I will give a try, hopefully it will work again.
CS, Christophe

Dick Bakker

Oct 14, 2021

I had some great shots with redcat and aap this year. guiding aroundf .6-.9 on windless nights and good PA.
even guiding <1.3with a 130pds on top.
unfortunately after firmware update AAP in august, the guiding is much worse. usually 1.0-1.5. what doesnt help is that the RA axis is not as smooth as before, perhaps due to the load with the 130pds. Fitting a teflon disc for smoother movement on RA axis seems to work for some people, perhaps i will give that a try. Now playing with a my new CEM70G, for the observatory. But hope to get the az gti better again for travel.

it is correct that after downgrading tot 3.20 the dec problem is solved, havent tried 3.32 yet.
CS

Albut

Jan 5, 2022

Christophe Perroud:
Dear astro-friends,

I ran yesterday on an issue while setting up my ASIAIR Pro to send guiding "pulses" to a new AZ-GTi I've recently bought from 2nd-hand. Despite many attempts with different settings in the ASIAIR App (DEC sets to Auto, South, North), I wasn't able to achieve DEC calibration nor guiding and could only rely on a good polar alignement and turn off DEC corrections to get round stars on 180’’ single frame.

Here is my setup :
76EDPH + Nikon D5500 + ASIAIR Pro + ASI120MM Mini + 30mm guidescope
AZ-GTi (v3.26A) connected through specific EQDir cable, fully supported by ASIAIR app latest version.

Except guiding in DEC, all features worked very well (polar align, focus aid, go-to function, meridian flip, auto centering target, dithering, home position) and send me to a new era of automatized AP session ;-) I really like this grab'n'go mount.

So, any though on that matter regarding DEC axis? I’ve read some posts on CN about that, but seems to be quite aleatoric from one user to others… It’s a little bit annoying as I’ve bought this mount to benefit from tracking and guiding on both axis comparing to my iOptron SkyGuider Pro who has RA only.

My next steps before going to an asylum :
- Downgrade firmware back to 3.20 as some users reported autoguiding on both axis with this old version?
- Double-check all settings in SynScan Pro and ASIAIR app I could have missed
- Double-check calibration settings in ASIAIR app. Any suggestion from experienced astrophotographers would be appreciated ;-)
- Balancing my equipment (4.5 kg in total) in DEC : does it play a role during guiding calibration that isn’t an issue at all while using just go-to command?
- What else?

Any help would be sincerely very welcome!

Christophe