Mach2 RA Judder


Brent Boshart
 
Edited

An issue with my RA axis has developed with my Mach 2.  Everything starts off fine and then I begin to notice egg shaped stars across my whole image and are elongated in the same direction as RA.  It does not matter if I expose for 2 secs or 30 secs, the shape is the same.  Tonight I was imaging saturn and the same issue suddenly started.  In the video below you can see saturn juddering back and forth while the mount is sidereal tracking.  The last few seconds in the video, I slew in RA at 1x and you can see it smoothen out.  I am not using tracking correction in APCC, in fact if I don't use APCC and the ASCOM driver only I get the same results.  Counterweights and shaft are tight. I have an AP 18lb weight near the top of the shaft and a 10lb weight about halfway down. The issue is happening frequently but is intermittent. 

https://www.youtube.com/watch?v=5kTmXjHhtVk


Brent Boshart
 
Edited

Here is a single short 20s sub showing the elongated stars.  A sub from 5s to 60s showed the same shape. At first I thought it may have been vibration in the camera fan, but it made no difference with the cooling fan on or off and it is in the exact direction of RA.


Brent Boshart
 

Just a fyi- Astro-Physics have contacted me directly and we are troubleshooting.  Great support as usual.


Bill Long
 

The best!


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Brent Boshart <bboshart@...>
Sent: Saturday, September 25, 2021 10:07 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Mach2 RA Judder
 
Just a fyi- Astro-Physics have contacted me directly and we are troubleshooting.  Great support as usual.