Settle Errors in NINA

[Tony De Nardo]

Hello all, I started receiving warning messages in NINA stating timed out while waiting for guider to settle.  This started about a month ago and I would get maybe one or two of those messages per night.  Now it seems to be doing it almost every dither.  I dither every 3 frames and it started, I was on M101 with 300s exposures for my lights.  The settings I was using were default (the same as when I first started using PHD2 at the beginning of the year and had no issues whatsoever).  Guide setup is Orion starshoot mini guider consisting of Orion mini guide camera 1280x1024 pixel size 5.2 and 50mm guide scope with 162mm focal length.  Imaging camera was ASI585MC at the beginning of the year and ASI533MC (as of the last 3 nights) on a Celestron OMNI XLT 150 reflector and a Celestron AVX mount.  No issues from the beginning of the year until about a month ago.  Last night It seemed I was getting errors on almost every dither.  I use NINA 3 point polar alignment and it has always done me well.  The last few nights I have been starting on IC4604 for a couple of hours and then heading East to M16 and finishing the night on that, both at 46 seconds exposure on the 533MC and I found before the session last night that I was dithering 5 pixels and with 2.32 arc seconds on the guide system and 0.77 arc seconds on the imaging system it was putting me to 15 pixel movement on the main image.  I lowered the dither to 3 pixels to bring me back to 9 pixels on the main image and still had the errors.  I ended up stopping the sequence last night to take a look at some things and ran a guide assistant.  it told me that I was 25 arc minutes off on PA which was odd because NINA told me that I was roughly 8 seconds total.  It also had a massive backlash number for DEC and recommended correction South only as well as move minimum from .17 to .15.  I changed the recommended settings. I reran 3 point polar alignment and sure enough, I was 25 minutes off!! I redid PA and started the session and it was fine for a few dithers and then went back to settle time out.  I notice very wild swings in the DEC corrections and the DEC RMS would build to over 3x RA.  I read about how the AVX has backlash issues on DEC and they recommended making minimal movements and lower aggressiveness so it does not overshoot when trying to correct.  I went back into settings and went back to AUTO for corrections, lowered aggressiveness from 100 to 70 and raised the min move from .15 to .18.  I restarted the sequence and it seemed to work fine for the next dozen or so dithers.  The DEC corrections would start getting a bit wild but then seem to correct and I didn't get any time outs in NINA.  I ended up going to bed and when I woke up, I had a screen full of time outs.  I pulled the DEC cover off this morning and the backlash has not changed from when I got the mount.  Being that guiding in south only which was recommended by assistant did not make a difference, I feel there is something else going on that I am missing and just cannot figure out.  Any help is much appreciated!!https://openphdguiding.org/logs/dl/PHD2_logs_Witu.zip

[Tony De Nardo]

I found a massive amount of backlash between the spur gears of motor and worm gear as well as even more backlash in the worm gear. I adjusted those and am going to try it tonight. 

On Sun, Jun 25, 2023 at 3:14 PM Simon Thompson <sit...@gmail.com> wrote:

I'm getting the same 'timed out' error using 2.611dev6 whereas before upgrading to dev6 no issues at all. I get more or less perfect PA in NINA using 3PPA and confirmed my PA in SharpCap whereas when I run guiding assistant in PHD2 my error is over 10 arm mins. Then after every dither NINA an PHD2 warning which shows a 'timed out warning waiting for guider to settle'. I'm going to try switching to dev5 of PHD2 tonight to see if that fixes my issues.

On Monday, 26 June 2023 at 2:50:41 am UTC+8 tony.de...@gmail.com wrote:

Hello all, I started receiving warning messages in NINA stating timed out while waiting for guider to settle.  This started about a month ago and I would get maybe one or two of those messages per night.  Now it seems to be doing it almost every dither.  I dither every 3 frames and it started, I was on M101 with 300s exposures for my lights.  The settings I was using were default (the same as when I first started using PHD2 at the beginning of the year and had no issues whatsoever).  Guide setup is Orion starshoot mini guider consisting of Orion mini guide camera 1280x1024 pixel size 5.2 and 50mm guide scope with 162mm focal length.  Imaging camera was ASI585MC at the beginning of the year and ASI533MC (as of the last 3 nights) on a Celestron OMNI XLT 150 reflector and a Celestron AVX mount.  No issues from the beginning of the year until about a month ago.  Last night It seemed I was getting errors on almost every dither.  I use NINA 3 point polar alignment and it has always done me well.  The last few nights I have been starting on IC4604 for a couple of hours and then heading East to M16 and finishing the night on that, both at 46 seconds exposure on the 533MC and I found before the session last night that I was dithering 5 pixels and with 2.32 arc seconds on the guide system and 0.77 arc seconds on the imaging system it was putting me to 15 pixel movement on the main image.  I lowered the dither to 3 pixels to bring me back to 9 pixels on the main image and still had the errors.  I ended up stopping the sequence last night to take a look at some things and ran a guide assistant.  it told me that I was 25 arc minutes off on PA which was odd because NINA told me that I was roughly 8 seconds total.  It also had a massive backlash number for DEC and recommended correction South only as well as move minimum from .17 to .15.  I changed the recommended settings. I reran 3 point polar alignment and sure enough, I was 25 minutes off!! I redid PA and started the session and it was fine for a few dithers and then went back to settle time out.  I notice very wild swings in the DEC corrections and the DEC RMS would build to over 3x RA.  I read about how the AVX has backlash issues on DEC and they recommended making minimal movements and lower aggressiveness so it does not overshoot when trying to correct.  I went back into settings and went back to AUTO for corrections, lowered aggressiveness from 100 to 70 and raised the min move from .15 to .18.  I restarted the sequence and it seemed to work fine for the next dozen or so dithers.  The DEC corrections would start getting a bit wild but then seem to correct and I didn't get any time outs in NINA.  I ended up going to bed and when I woke up, I had a screen full of time outs.  I pulled the DEC cover off this morning and the backlash has not changed from when I got the mount.  Being that guiding in south only which was recommended by assistant did not make a difference, I feel there is something else going on that I am missing and just cannot figure out.  Any help is much appreciated!!https://openphdguiding.org/logs/dl/PHD2_logs_Witu.zip

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[Bruce Waddington]

In order to figure these things out, you really need to use the PHD2LogView tool and see exactly what's going on with the mount.  As you have concluded, the mechanics on the Dec axis are very poor, but it isn't simply a matter of backlash.  Here's a typical view (Dec in green):

So there are many things going wrong here.  To start, you're generating these large dithers (20 arc-sec) which make a high demand on the Dec drive system.  You can see there is a very large amount of backlash - note how long it takes for the mount to start moving after a series of guide commands are sent.  Typically, it can take at least 8 consecutive guide commands of 350ms to 2.6 seconds before the axis starts moving.  Even worse, the 5-second guide camera exposures mean these 8 consecutive guide commands will take over 40 seconds of elapsed time!  Finally, once the Dec axis finally starts moving, it over-shoots the target - a classic sign of stiction.  This puts the axis into oscillation and it can take a very long time to stabilize. So you can't just keep tightening things because you will probably make the stiction worse.  You can read about these kinds of problems here:

https://openphdguiding.org/man-dev/Supplemental_Info.htm#Common_mount_problems

Unless you can get this fixed, you should probably do dithering only in RA. 

Good luck,

Bruce

[mj.w...@gmail.com]

Hi Tony

Are you sure it's a 50mm guidescope?

Those typically have a 200mm FL, not 162mm.

A 40mm guidescope would be 162mm

Anyhow, assuming it is 162mm, the pixel scale is 6.62arcsec/pixel.

Imaging pixel scale is 1.03 arcsec/pixel.

So Dithers of 2 would give you the usual approx 12pixels.

Also I noticed on the last Cal you had selected different RA and Dec guiderates in the mount.

PHD2 threw up an error message  "RA Guide Speed = 7.5 a-s/s, Dec Guide Speed = 9.0 a-s/s, Cal Dec = -13.7, Last Cal Issue = Difference,"

And calculated the rates as "Norm rates RA = 7.6"/s @ dec 0, Dec = 9.2"/s"

Michael

Wiltshire UK.

On Monday, 26 June 2023 at 03:33:38 UTC+1 sit...@gmail.com wrote:

Hi Bruce, thanks for your input. Log files can be seen here https://openphdguiding.org/logs/dl/PHD2_logs_nRjr.zip

On Monday, 26 June 2023 at 10:20:35 am UTC+8 bw_m...@earthlink.net wrote:

That’s one approach.  A better approach might be to analyze the log files and see what’s actually happening with the mount.

 

Bruce

 

From: open-phd...@googlegroups.com <open-phd...@googlegroups.com> On Behalf Of Simon Thompson
Sent: Sunday, June 25, 2023 3:15 PM
To: Open PHD Guiding <open-phd...@googlegroups.com>
Subject: [open-phd-guiding] Re: Settle Errors in NINA

 

I'm getting the same 'timed out' error using 2.611dev6 whereas before upgrading to dev6 no issues at all. I get more or less perfect PA in NINA using 3PPA and confirmed my PA in SharpCap whereas when I run guiding assistant in PHD2 my error is over 10 arm mins. Then after every dither NINA an PHD2 warning which shows a 'timed out warning waiting for guider to settle'. I'm going to try switching to dev5 of PHD2 tonight to see if that fixes my issues.

On Monday, 26 June 2023 at 2:50:41 am UTC+8 tony.de...@gmail.com wrote:

Hello all, I started receiving warning messages in NINA stating timed out while waiting for guider to settle.  This started about a month ago and I would get maybe one or two of those messages per night.  Now it seems to be doing it almost every dither.  I dither every 3 frames and it started, I was on M101 with 300s exposures for my lights.  The settings I was using were default (the same as when I first started using PHD2 at the beginning of the year and had no issues whatsoever).  Guide setup is Orion starshoot mini guider consisting of Orion mini guide camera 1280x1024 pixel size 5.2 and 50mm guide scope with 162mm focal length.  Imaging camera was ASI585MC at the beginning of the year and ASI533MC (as of the last 3 nights) on a Celestron OMNI XLT 150 reflector and a Celestron AVX mount.  No issues from the beginning of the year until about a month ago.  Last night It seemed I was getting errors on almost every dither.  I use NINA 3 point polar alignment and it has always done me well.  The last few nights I have been starting on IC4604 for a couple of hours and then heading East to M16 and finishing the night on that, both at 46 seconds exposure on the 533MC and I found before the session last night that I was dithering 5 pixels and with 2.32 arc seconds on the guide system and 0.77 arc seconds on the imaging system it was putting me to 15 pixel movement on the main image.  I lowered the dither to 3 pixels to bring me back to 9 pixels on the main image and still had the errors.  I ended up stopping the sequence last night to take a look at some things and ran a guide assistant.  it told me that I was 25 arc minutes off on PA which was odd because NINA told me that I was roughly 8 seconds total.  It also had a massive backlash number for DEC and recommended correction South only as well as move minimum from .17 to .15.  I changed the recommended settings. I reran 3 point polar alignment and sure enough, I was 25 minutes off!! I redid PA and started the session and it was fine for a few dithers and then went back to settle time out.  I notice very wild swings in the DEC corrections and the DEC RMS would build to over 3x RA.  I read about how the AVX has backlash issues on DEC and they recommended making minimal movements and lower aggressiveness so it does not overshoot when trying to correct.  I went back into settings and went back to AUTO for corrections, lowered aggressiveness from 100 to 70 and raised the min move from .15 to .18.  I restarted the sequence and it seemed to work fine for the next dozen or so dithers.  The DEC corrections would start getting a bit wild but then seem to correct and I didn't get any time outs in NINA.  I ended up going to bed and when I woke up, I had a screen full of time outs.  I pulled the DEC cover off this morning and the backlash has not changed from when I got the mount.  Being that guiding in south only which was recommended by assistant did not make a difference, I feel there is something else going on that I am missing and just cannot figure out.  Any help is much appreciated!!https://openphdguiding.org/logs/dl/PHD2_logs_Witu.zip

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[Tony De Nardo]

Thank you for the reply, yes 50mm and 162mm FL is what it is advertised at least. I changed the DEC speed rate as when I was watching, it would have RA corrected quickly after a dither and DEC was still trying to correct . When it would time out, it was always DEC still out of acceptable range. 

To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/4f844d76-f3ca-4e90-960c-2326fd36407fn%40googlegroups.com.

[Tony De Nardo]

I am happy to report no issues last night after adjusting DEC gearing adjustment. I had a couple of wild swings during the night, but recovered flawlessly. I will continue to fine tune and see where it goes. Thank you all for our help!