PHD 2 RA correction issue

[michael8554]

10 hours ago, 5haan_A said:

I basically took on board everything that has been said in here and managed to guide with PHD2!

I don't think you read and applied any of  the "Best Practices" written by the PHD2 developers that I gave you a link to ?

Louise is too polite, Calibration looks awful I'm afraid, you need to sort that out if you want acceptable guiding.

A Screen Print gives a better view than a screen grab, we don't need to see your PC keyboard ! Use the PrtScrn button on your PC which will save to the Clipboard. Then Crop to the framing you want.

You're still guiding at X 0.10, I don't know if that's what is recommended for belt drives, but at least X 0.50 is more usual for guiding. PHD2 may struggle to make big enough guide corrections.

This may explain why Calibration took 39 steps instead of the expected 12 or so.

PHD2 recommends Calibrating at zero Dec, you Calibrated at +20.

PHD2 usually recommends exposures between 1 and 3 seconds,  you've actually gone up to 4 secs - was that a Guiding Assistant recommendation ?

We're all trying to help you but you don't seem to be listening.

Michael

 

[5haan_A]

59 minutes ago, michael8554 said:

I don't think you read and applied any of  the "Best Practices" written by the PHD2 developers that I gave you a link to ?

PHD2 usually recommends exposures between 1 and 3 seconds,  you've actually gone up to 4 secs - was that a Guiding Assistant recommendation ?

We're all trying to help you but you don't seem to be listening.

Michael

 

It literally says on the third page use loops of 2-4 seconds. What can you do if the only star you can calibrate on is around 20 DEC? 

I'll change the guide speed and increase the speed.

As I said in my post, I did manage to guide. I'm not sure how, but it did work, however I'm glad to hear that it could guide better. 

Thank you for your help Michael.

[michael8554]

9 minutes ago, 5haan_A said:

It literally says on the third page use loops of 2-4 seconds. What can you do if the only star you can calibrate on is around 20 DEC? 

Okay, my mistake, but try 2 secs.

Yes, you have to have a star to be able to Calibrate ! But I've only got a budget ASI 120MM guidecam, even that finds stars everywhere, what have you got?

I know I've been hard on you but you're wasting these clear nights !

Michael

[5haan_A]

7 minutes ago, michael8554 said:

Yes, you have to have a star to be able to Calibrate ! But I've only got a budget ASI 120MM guidecam, even that finds stars everywhere, what have you got?

Yeah we have a similar camera. No problem with picking up  star in it. It's more a logistical one I cant see anything at that level due to terrain and a house. Would you say it would be worthwhile taking the set up to a different site where I can calibrate at 0 DEC?

 

Don't worry about being too hard, I know you're only trying to help. 

 

Best, 

[michael8554]

9 hours ago, 5haan_A said:

Would you say it would be worthwhile taking the set up to a different site where I can calibrate at 0 DEC?

 

No, do the best you can, PHD2 will accommodate, they recommend zero Dec as that's where the stars appear to be moving fastest, which tasks PHD2 the most.

Michael 

[johngm]

Hi 5haan.

Not quite the same issue but very similar, please read my thread.

I tried all sorts of things, I even wasted over £200 on a new motor control board. Whatever I did, I could not get it to calibrate with PHD2.  it would calibrate west, then would not east step and came up with calibration failure. I then had a brainstorm and tried an old windows XP laptop I had, due to the fact that I tried everything else. Then, et voila, it worked sweet as a nut. Are you running windows 10 64 Bit ? because in my case, this was definitely the case. At first, everything was great, but when I think back, it all started with one of the dreaded widows updates. If you have an old PC or Laptop with XP, please try this, and report back, because I would love to know I am not alone, and this could be helpful to other fellow stargazers.

 

Regards John

 

[johngm]

Hi, 5haan,

As a footnote, I tried everything on here what other guests have suggested, increasing loop times, played around with other PHD2 settings etc, all to no avail. And BTW, I am using exactly the same guide Cam as you.

John

[Starflyer]

On 01/09/2019 at 19:52, Thalestris24 said:

So you need to be in perfect balance. No concern about engaging motor gears. The bullseye target will show you if you have a balance-related drift.

I'm not sure this is true, can you quote a source where this is discussed?

I thought the theory was to offset balance whenever you've got backlash. Surely there's backlash still present between the worm and worm wheel in a belt driven system, unless you've got a fancy zero backlash mount.

 

Ian

[Thalestris24]

Just now, Starflyer said:

I'm not sure this is true, can you quote a source where this is discussed?

I thought the theory was to offset balance whenever you've got backlash. Surely there's backlash still present between the worm and worm wheel in a belt driven system, unless you've got a fancy zero backlash mount.

 

Ian

Yes, you can have worm engagement problems but it's the motors which drive the axes. Being unbalanced doesn't help the worm engagement but you can adjust that. The worm gears have very small teeth compared to the non-belt driven motor gears. In my own experience with an heq5 with belt drive, I get the best results when my scope is accurately balanced in all 3 axes.

https://www.cloudynights.com/topic/484545-whats-the-advantage-of-belt-drive/

Louise

[Starwiz]

Just to add, in addition to the good advice given so far - it's a good idea to run all your applications as Administrator.  I don't know if it will help or not, but I've had all sorts of weird things happening when I don't.

John

[raf2020]

Sorry, I haven't read whole thread but I had same problem after my mount has passed meridian and didn't do the flip (my fault as I haven't turned on auto flip in APT nor forced it).

[kens]

On 01/09/2019 at 21:17, 5haan_A said:

So last night I had some success finally. I basically took on board everything that has been said in here and managed to guide with PHD2!

 

I made sure that my PA was as good as could be. 

I reinstalled PHD2 and recalibrated. I have attached the calibration data. I still wasnt happy that I got an orthogonal error of 14. PHD2 was saying that it should be below 10, but it was close enough.

I then managed to guide without major hiccups. I have attached some log data also. The only issue I had throughout the session was the images PHD2 were taking were variable. There was some sharp images were the stars were all visible through the findersope and it was happy, and there was some dim images were all but the brightest stars through the finder would disappear. This meant that there was significant star mass change from frame to frame. Not ideal but it meant that PHD2 would lose sight of the star for let's say 1 frame in three. It would pick it back up again the frame later so it was actually fine and didn't affect the session too much. 

Anyway thanks for the help, and if any of the info I provided can be used to give some more feedback it would be appreciated. 

 

 

@5haan_AI'm surprised that nobody has asked you to attach your guide log FILES rather than relying on screen shots. Screen shots are, frankly, useless for diagnosing issues.

The help menu will take you to the logs.

A quick glance at the screen shot does suggest that you have your guide rate set to 0.1x sidereal. The logs would help confirm this. It should beat least 0.5x. Unfortunately the EQMOD  driver defaults to 0.1x which is an unsuitable value in most cases.

Ther may also be other issues but that would be a good starting point.

Edited December 24, 2020 by kens