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PHD poor guiding

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#1 syxbach

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Posted 14 March 2019 - 09:15 PM

Hello folks

 

I got a nice Vixen ED115s yesterday. I paired it my NEQ6 and SBIG STF8300 camera with OAG. The updated Moonlite autofocuser was found to be successful during the initial test, however, I got really poor guiding. The first thing I noticed is during calibration, I heard quite noisy sounds when clearing the backlash. The second thing I found is that the dec is not balanced from left to right because the extra motor of the Moonlite focuser.

 

I guess the calibration maybe wrong because of the wrong parameters. The unbalanced dec may also cause the problem. The scope is definitely longer than my previous ED103S. I would appreciate it if you could help on this. I attach a snapshot of my guiding graph. Thanks!

 

Yuexiao

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Edited by syxbach, 14 March 2019 - 11:46 PM.


#2 rgsalinger

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Posted 14 March 2019 - 09:56 PM

If you want help then post a log. The small imbalance caused by the motor is not going to cause problems like this or I miss my guess. Only with a log can anyone truly know how to help you. Try rotating the scope so that the motor the imbalance is minimized or if this turns out to be the problem, put some weight on the other side. 



#3 Jim Waters

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Posted 14 March 2019 - 11:38 PM

Post this on the Google PHD Guide 2 Forum and include you PHD Logs.  I know nothing about your mount but RA and DEC balance is critical.  

 

https://groups.googl...pen-phd-guiding



#4 rgsalinger

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Posted 14 March 2019 - 11:44 PM

If the OTA is installed in the usual manner with the focuser down, then the motor is a couple of ounces and it is NOT orthogonal to either the DEC or RA axes. It's actually presents a rotational force in a third axis. So, you can perfectly balance the mount in DEC and RA but still have that third axis unbalanced. There are a number of solutions to this, BUT unless he's mounted the motor in a really strange manner I'm still of the mind that the motor's weight is not the problem with this class of mounts. Something else is going on. He needs to save and post a log somewhere, that's for sure!

Rgrds-Ross



#5 syxbach

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Posted 14 March 2019 - 11:44 PM

Post this on the Google PHD Guide 2 Forum and include you PHD Logs.  I know nothing about your mount but RA and DEC balance is critical.  

 

https://groups.googl...pen-phd-guiding

Thanks Jim. I post this issue on that forum with my log file.

 

Yuexiao



#6 syxbach

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Posted 14 March 2019 - 11:47 PM

I uploaded my log file. I calibrated twice, but neither of them worked.

 

Best

 

Yuexiao

If you want help then post a log. The small imbalance caused by the motor is not going to cause problems like this or I miss my guess. Only with a log can anyone truly know how to help you. Try rotating the scope so that the motor the imbalance is minimized or if this turns out to be the problem, put some weight on the other side. 


Edited by syxbach, 14 March 2019 - 11:47 PM.



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