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SkyX Tpoint Anomoly

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#1 jsowens

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Posted 21 January 2021 - 09:40 PM

I have a thread going on over on the Bisque forum but I thought maybe someone here had a similar experience.

 

I’ve run three, 300 target, Tpoint models over 3 nights and keep getting around 30 RMS. 

 

I have the following setup:
- Edge14 on an MX+
- Optec secondary focuser
- .7 reducer to an SX35 CCD and a Maxi filter-wheel

In addition to the subpar RMS, there appears to be a symmetrical pattern across the scatter plot that I’m hoping might look familiar to someone.

 

Some other useful information:
- The balance is near perfect in RA & DEC
- There are no cables interfering (I rerouted everything)
- The primary is rigidly locked using Optec locking knobs
- The AP train connected using only threaded, machined, aluminum components
- Mount sits atop an 8″ diameter 1/2″ wall steel DOM pipe pier
- Aztrozap dew shield

- I verified all pier and mount bolts are as tight as possible

 

I know I can do better as my last model was around 15 RMS with the same scope/mount/pier….only difference was that was with a Hyperstar configuration and used the primary to focus.

 

Please find supporting files on my GoogleDrive.
https://drive.google...llB?usp=sharing

 

I’m really stuck as to what’s causing this error.  Help!


Edited by jsowens, 21 January 2021 - 09:41 PM.


#2 555aaa

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Posted 21 January 2021 - 09:57 PM

All the tpoint model terms have physical meaning. The tool will also show you the uncertainty on each term. Turn off the terms with high uncertainty. Also is this on one pier side only or both?

#3 jsowens

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Posted 21 January 2021 - 10:12 PM

Thanks for the quick reply

 

I dropped a screenshot in the folder to who the terms

I don't choose them, I let the supermodel to that

Can you tell from the terms what type of issue is causing that pattern?

 

The models I run are across the entire sky between 10* and 90* Alt



#4 Sacred Heart

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Posted 23 January 2021 - 04:29 AM

I am new to Sky X, but what does your polar alignment information saying??  Are you within knob clicks away from polar align.  With Sky 6, I would get within knob clicks away, then do another automated mapping run  and done.  Again I am new to Sky X,  learning it myself.   Way different animal from Sky 6.

                  Joe



#5 pyrasanth

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Posted 23 January 2021 - 05:29 AM

I guess you ran the super model setting?

 

Have you reached out to the Bisque support forum- you will get excellent help there?

 

On my Paramount MX+ using Bisque rings I get the following with a 500 point model and the terms below in the screenshots.

 

model2.PNG

 

model3.PNG


Edited by pyrasanth, 23 January 2021 - 05:31 AM.


#6 555aaa

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Posted 23 January 2021 - 10:45 AM

A C14 has a moving mirror even when locked down. In both cases you have good pointing imho. Is it really a problem? I also would not use points below about 30 degrees elevation and you didn’t say if your model is a composite of east pier side and west or one side. It’s better to have an east side model and a west side model. I have TheSkyX but since my mount doesn’t need to flip I have a single model.

#7 jsowens

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Posted 23 January 2021 - 02:34 PM

Thanks for the feedback everyone....and sorry for the short answers but travelling this weekend

 

Sacred Heart - Polar alignment is informed by the model.  Until the model is working well the PA recommendation cannot be trusted.

 

pyrasanth - Yes....I supermodel after every 12-15 targets so following targets use previous targets fit.  Been troubleshooting with Patrick on the SB bisque site.  He's the best of the best.  Posted here hoping someone had a similar issue and a fix.  I get 12-14 RMS with my Hyperstar setup.....I moved the AP train to the rear and am now getting 30+......this is my issue.

 

555aaa - The primary is locked down rigidly using Optec's brass lock knobs....its doesn't move.  The pointing isn't horrible but Iv'e had better with this OTA/Mount so I'd in pursuit of what I know the system is capable of.  And my @300 point model is full sky.....30* alt up to 89*




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