Re: Fw: Coord issue? Video attached via dropbox

Dan Gray

Sounds like the guider was keeping it centered, and either there's a setting wrong in the SiTech.cfg file, or polar alignment/slippage.
Here's what to look for in the SiTech.cfg file.
Make sure you edit the SiTech.cfg file when SiTechExe is not running
Also motor ticks per rev could be wrong,
Balance and roller pressure are critical.

They should both be zero.
The reason I mention this possibility, is this got changed somehow in someones config file.


On Thu, Feb 11, 2021 at 10:12 AM jaspal <jaspaltheknight@...> wrote:

From: Jaspal Chadha <jaspaltheknight@...>
Sent: 11 February 2021 16:29
To: <>
Subject: Coord issue?

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 

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