PEC bench test


Chad Gray
 

Is there a bench test for PEC?  The Ohio weather is not going to cooperate to test it in wild

I got Home switches and Limit switches working on the CGE Pro.  I love the home switches!  I have not had a mount with those before.

Thanks,
Chad


Chad Gray
 

I found Howards software that displays the PEC data.  Looks like i am good.  I still need to learn what is going on, but i have data!

image.png


On Fri, Dec 31, 2021 at 4:12 PM Chad Gray via groups.io <rchadgray=gmail.com@groups.io> wrote:
Is there a bench test for PEC?  The Ohio weather is not going to cooperate to test it in wild

I got Home switches and Limit switches working on the CGE Pro.  I love the home switches!  I have not had a mount with those before.

Thanks,
Chad


John Scherer
 

Khalid wrote his OnStep python api that does a lot, but I don’t think it reads PEC data.  


https://github.com/kbahey/onstep-python


Khalid Baheyeldin
 

On Sat, Jan 1, 2022 at 11:13 PM, John Scherer wrote:

Khalid wrote his OnStep python api that does a lot, but I don’t think it reads PEC data.  


https://github.com/kbahey/onstep-python

Yes, it does not do PEC.
It only reports whether PEC is active, and whether it is recorded.
All that added today by someone who found the API useful.

So it can dump PEC, if someone wants to add it.
Write the code, test it and submit a patch, and it will be in for future users.

And while we are talking about that API, I added preliminary code to measure backlash,
and set it to what it is measured. But it did not work. Anyone having an interest it making
it work, please go ahead.


smith_barry
 

Hi Khalid, this looks interesting trying to get into python myself so may have a look at the code.  As per the email re encoders PEC will be interesting on my harmonic drive set up partly because it covers a full revolution of the alt axis.  The difficulties of relating this to a star test also exist and links to the issues of trying too optimise your mount during poor weather raised by the original poster.    
Thanks for your contribution on my encoder post.
Barry


smith_barry
 

Unfortunately you probably need an accurate and precise encoder to tell you where the scope alt axis is.  I used the following setup with a different driver but shows you the type of plot you can generate whilst as home in cloudy weather.  The data is for a Losmandy G11 with std worm on alt axis set to rotate at a theoretical rate of 15 ArcSeconds/S  with a balanced 100mm refractor.  The encoders used were both sin/cos with interpolation factors set to give around 6million pulses per rev (all found on ebay) Heidenhain (image 6194) and Cannon (5987).  How useful such a setup is to tuning a mount remains to be seen as due to work commitments I never got to compare against a more optimised system and more importantly the real world.
Barry