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Coord issue?


jaspal
 


Hi all,
                Can I please pick your brains? so as you are aware I have been having issues with my Mesu Mark 2 mount  drifting every second in RA making it unusable or guidable at times. After in contact with Lucas Mesu and problem solving I changed to a new computer, rebalance and cable management, it's early days to say 'WHOOP WHOOP problem solved' but yesterday it went fine for the hour and half i had ( only tested in the WEST )

I use Voyager software that controls everything and all the drivers are up to date

I start voyager, mount is pointing WEST

Sitech showed the mount as tracking.... 'I completed a Plate Solve Actual Coord' and the Sitech box appeared and press INIT to confirm ( making sure the bottom bit showing WEST) and then press SYNC in voyager and the RA and DEC readings are the same... 

Voyagers allows you to search for target and uses ALADIN to show what image looks like in your pre-defined FOV setup, You can also free search around sky screen and do a precise Goto which will plate solve the target.   

Last night I choose target NGC457 and it slewed in bang onto to my FOV I then began PHD2 guiding and was at around TOT 0.50. 

After consistent frames  perfectly centred  I pressed the 'Get telescope position' It showed that the scope had moved considerably away from the target, however each frame it was still bang in the middle of the FOV and guiding graph good.

see images below ( first image shows R.A 01:18:11:8 and DEC 58:23:41 in SITECH ) and the in Voyager RA 01:18:12 DEC 58:23:41)




Second image shows actual telescope position within 30 mins or so of imaging




Third image shows the actual sub frames coming out which is dead centre and not repsentative of image 2 (above)  




The developer of Voyager states, usually mount work in JNow or you have done a wrong sync or not right epoch seems & can't help further 

Could this possible be causing RA drift, something clashing? 

Thanks in advance 


Don W
 

Hi Jaspal,
I don't see your problem.  You said you setup on NGC 457 and took images all centered on it.  Then 30 minutes later you pressed "get telescope position" and Voyager showed you image two, which is clearly marked J2000 coordinates and is a projection of the FOV by Voyager.  It is not real.  The J2000 coordinates are way over right of the JNow coordinates, as your image shows.
Don W


Jaspal Chadha
 

Ah thought telescope position would be in real time, so it wouldn’t off move that far of the original goto, like shown in image 2. I thought it would stay there as it’s still centre in image 3  


On 11 Feb 2021, at 20:05, Don W <westergren@...> wrote:

Hi Jaspal,
I don't see your problem.  You said you setup on NGC 457 and took images all centered on it.  Then 30 minutes later you pressed "get telescope position" and Voyager showed you image two, which is clearly marked J2000 coordinates and is a projection of the FOV by Voyager.  It is not real.  The J2000 coordinates are way over right of the JNow coordinates, as your image shows.
Don W


dan adi
 

So everything tracked well? 0.5" RMS seems reasonable.


Jaspal Chadha
 

Yes tracked well but the issue is so intermittent


On 11 Feb 2021, at 21:06, dan adi via groups.io <cioc.adriandan@...> wrote:

So everything tracked well? 0.5" RMS seems reasonable.


dan adi
 

I for example had some issue with the mount starting slewing on its own, with no input from me. Scope hit the pier, ccd fell down but luckily no damage done. After I reinstalled sitech.exe the issue went away.... Didn't happen again. That said now I have a big refractor and I worry the issue will reappear, hope not :)) 
If things start to go wrong again, I will reorient myself towards 10 micron.