7 replies to this topic

[DrJack]

I can not calibrate and guide with my ASIAir/ AM5. This only started happening yesterday.The only equipment that was changed was the 'main' scope.
 

Equipment= 30 mm SVbony/ ASI120MM connected to an ASIAir Mini on an AM5 mount.
Dec duration = 1900, max RA/ DEC pulse is 150 (changing these from the default has not appeared to matter)

When I initiate calibration, it goes fine in the initial (west) direction and reaches 25 and 20 steps. When it reverses, the amount moved back with each step decreases and then reverses so that east step 0, instead of being 0, is back to 25. Roughly the same happens North / South. When you look at the PhD2 tracking window/ graph,  RA and Dec are not at 90 degrees to each other and I can never correct enough to guide. Has anyone seen anything like this before?

Edited by DrJack, 10 October 2024 - 07:33 AM.

[michael8554]

1. "it goes fine in the initial (west) direction and reaches 25 and 20 steps."

 

Which, can't be both ?

 

2. Polar Alignment error and Dec Backlash can cause the orthogonality error (not 90), and cause the south move to end up not at the origin.

But a reversal is unusual.

If the mount has a Dec Backlash Compensation setting, disable that.

 

Need to see a LINK to a GuideLog.

[DirtyRod]

You mentioned an ASIAir but also PHD2. Which are you using? Since you mentioned the PHD2 calibration graph, I assume you are using that and are not actually running An ASIAir to guide?!?!? 
 

[DrJack]

1. "it goes fine in the initial (west) direction and reaches 25 and 20 steps."

 

Which, can't be both ?   It will reach 25 pixels West in 20 steps. When it goes East, it never reaches 0 but goes at a slower rate and reverses, ending up back at 25 pixels West.

 

2. Polar Alignment error and Dec Backlash can cause the orthogonality error (not 90), and cause the south move to end up not at the origin.

But a reversal is unusual.

 

The mount was polar aligned before calibrating. 

 

If the mount has a Dec Backlash Compensation setting, disable that

 

This is an AM5. It technically has no backlash and there is no Dec backlash setting that I am aware of

 

You mentioned an ASIAir but also PHD2. Which are you using? Since you mentioned the PHD2 calibration graph, I assume you are using that and are not actually running An ASIAir to guide?!?!?

 

I am using an ASIAir. It uses a simplified version of PhD2. If I could figure out how to upload a screen shot of the graph, I'd be happy to do it.

[michael8554]

Leaves many possibilities.

Guidelog required

[sbsbbugsy]

Try clearing your old calibration and see what happens.

[DrJack]

I do that every time I start a new session. No effect.

[900SL]

20 steps is too much. You only need around 7. Your calibration settings are too short. What area of the sky are you calibrating in?