Re: Excessive Slew Warnings in APPM


 

Hi Brent

I have experienced that as well. My decision was to leave the high accuracy slews enabled and live with those warnings.

Prior to having the high accuracy option available, my main concern was streaking stars for model building . I have run a number of 300 point models and kept all the frames to review. I would often see a handful or more of plates with streaking stars

Sometimes these streaking stars would cause plate solve to fail, but other times the solve would work even if the stars weren't pinpoint. I was worried this could create inaccuracies in the model. Since I enabled high accuracy, I only get pinpoint stars in the model building and no failed solves. I have set my settle time around 10 seconds (it's a big 20" CDK). 

hth

Brian




On Mon, May 9, 2022 at 6:44 AM Brent Boshart <bboshart@...> wrote:
I have been trying to troubleshoot excessive slew warnings (over 50%) when building models in APPM. From observing the Dec coordinate values in APPC I believe it is the Dec axis.  Here is what I have done:
 
I have meticulously balanced the Dec axis. During a live view, I rapped my pier and the mount with my hand and the view settles within 2 seconds or less.
 
I ran a test with the "Settle Time" as high as 60 seconds and had the same frequency of slew errors compared to an 8 second settle time.
 
I earlier had worked with A-P to increase encoder dampening trying variations from my original to the maximum suggested. Btw, this is not with a very heavy payload - a Stowaway with ASI2600MM/filter wheel/OAG.
 
I have examined the model building images and the stars appear round.
 
When I watch the Dec coordinate readout in APPC during the settle time, I can pretty much tell when I will get a slew warning by the amount of fluctuation of the reading. I guessing 0.5 arcseconds is the cut-off point to issue a warning? Sometimes my reading can fluctuate as much as 0.8 arcseconds but usually around 0.5-0.6 when I get the warning. The RA axis readings seem much more stable (even when multiplied by 15 to get the same units).
 
So my question is does this matter or am I chasing something inconsequential - do I uncheck "Require high accuracy slews" and be on my way? Or what would I try next? Is there perhaps a mechanical tweak I need to try with the Dec axis?   



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