Re: Mesu 200 Mk2 Tracking stops close to equator

Yann-Eric Boyeau

Hi Torben,

Looking at the graph of the Guiding assistant, it is easy to see that you have a nice negative and constant drift of 5,8 arcs/min.
I think the ticks/rev configured for your mount are wrong.
If you show this graph to Mr Mesu, he will explain how to fix this. You have to use servoconfig.

I used to have some drift with my Mesu200 and I managed to correct the number of ticks.
This SGL post also explain how to do it : Ticks/rev can vary with temperature, load and tension. I iterated the correction until I got no more tracking improvement in guiding assistant.

I understand your frustration at this point. I live 22 000 km from Netherlands and did not have the option to sent back my mount... so I fixed it. And I am happy with it now.

Sorry you had a bad experience with Mesu.


From: <> on behalf of T. van Hees <torben@...>
Sent: Thursday, February 18, 2021 02:44
To: <>
Subject: Re: [Sitechservo] Mesu 200 Mk2 Tracking stops close to equator
Hello again. I am grateful for all the assistance I got in this community, so here is my most recent data. In the link you can find two of my recent guiding logs. Many of the log parts are with dithering because I just let Voyager run for the rest off the night, as I could not get the drift under control. I just took very short exposures with the RASA so got some data nevertheless. There is one run of Guiding Assistant, also attached as a screenshot. Within the logs, there is one run where DEC stops responding to guider commands: This is due to me not correctly tightening a clutch, not a mount error.

You will find RA drift between 2.5" and 14"/minute as well as some 20-30s spikes. I have tested again with a lighter and proven setup (my RC8 with OAG). I have currently no access to the log but I can describe the results: The 30s-spikes are far smaller, barely detectable (0.2" instead of 1"), but the RA drift was the same. DEC always seems to correct fine with both setups. That same setup works without problems on a Heq-5, so I think I can safely ignore a flex error. I realise longer logs might be beneficial to diagnose what exactly is wrong with the mount, but I can not present those. I have no more interest to tackle this problem and am in the process of contracting a Dutch lawyer to try and settle the whole mess for me and cut my losses. Dealing with Mr Mesu has been tedious and exhausting. I want nothing more to do with him and his business. I feel sorry that more people than just me are affected.

Links to logs:

Join to automatically receive all group messages.