New Mesu 200 mk2 mount at the observatory.

Ok, let’s go.

I receive the mount in a perfect package on Friday.

On the weekend I mounted on test (on a table) for start configuring the Sitech Ascom software and test the general behaviour, SGP integration, etc..

On Saturday, it was necessary to prepare a rj10 cable to serial db9 for the new controller and then use a usb<>serial converter. In my case usually I use the PL-2303 Profilic controller available in so many converters.




The USB cable will be included on next shipments.






Sunday, I went to the observatory to change the mount, you could see all the works on the video.

The initial idea was to use the same RC10 from the Astro-Physics Mach1 on the Mesu200 mk2 but it was not possible because the counterweight bar cannot fit my Geoptik counterweights.

The Geoptik counterweights are announced to use it on Mesu.

On Mesu 200 mk1, Geoptik counterweights are used for many people but the new bar is lightly bigger in diameter than the previous one and cannot fit them.

Of course, the original Mesu counterweights are compatible and I know that exists some contacts between Bernard from Modern Astronomy and Geoptik to change the specs on Geoptik Counterweight to 40.5mm.

To continue the installation, I decided to use the AP Mach1 counterweight bar on the Mesu (it was possible to adapt) but the leftover size of the counterweight bar is only about 30cm long and only could use 15kg.

I switch to my 107mm refractor to continue with the installation. The new pilar adarter was place and the wedge oriented to the north.

I sent the counterweight bar to the workshop to slim down 0.2mm and I received yesterday (really thanks to those colleagues who cares about that, on summer holidays and with not time frame to do it….)

It’s a big bar: 800mm x 40mm and in some cases maybe is better to increase the size of the center hole on the counterweights.

Sunday night I started the first test under the night sky, and I saw some problems when I try to check the goto all around.

I was run some PointXP models (16 positions) with the same unsuspected result.

After some investigations I notice that the Dec axis slips.

The telescope was perfectly balance and the problems seams to be on the axis because even without telescope slips in some positions.

On Monday we set several Skype video conferences with Lucas Mesu for understand what happens.

The mount was extensively tested on his workshop before sending it to me.

After several procedures (and hours), dissembling the brake system, cleaning the big drive wheel, etc. we saw that the problem was with the pressure of the motor with the drive wheel. It was adjusted manually following the directions of Lucas (is pending a more accurate procedure) and now the mount seems that is working well.

Further explanations of Lucas Mesu point to the way how the mount was sent to me. The mount was split in two packages, one per axis, and the internal block drive on Dec was not properly attached for transportation. For sure this will be solved on next shipments.

The polar alignment was easy, first you set the wedge roughly to the north and with the Polemaster on the telescope the alignment final was question of 5 minutes with an error of 0.3 arc-min.

I would like to say that it was a surprise to me how stable is the alignment process, when you are doing the fine adjustment on Polemaster (the green box and the red circle) the movement is quite smooth and using a proper wrench is really easy to do.

First real capture test with the mount starts on Tuesday and the results are really good.

With a polar alignment of 0.3 arc-min, I could obtain a sustain 0.33″ RMS with no especial configuration on PHD2, only long exposures of 8 sec. with the standard configuration provided by the wizard.

Sometimes I could see a 0.20″ RMS measures for a shorter period.

I don’t like to compare but sometimes it is necessary. With my previous mount, with same capture equipment (and skills) the RMS was 0.69″, not bad at all, really good I could say.

With my current config I think this is the limit, it’s an ASI174 on 546mm OAG at 2.2 ” per pixel and 1.53″ per pixel on the main camera.

I want to check the PointXP mapping with this mk2 version, some people don’t use it on the mk1 because the small slips inherent to this kind of mount. The sense of this mapping is to improve the guiding, the current goto are really ok and I use Platesolve extensively.

I have plans to create models with PointXP and check how it guide and see how much errors are introduced by the slips.

Also, it’s pending a PemPro test for look on the periodic error with no corrections.

I will share this info and further data from PHD2.

And finally, at some point, I wish to see the results with my 107 and RC10 in dual rig configuration (this was the main reason to change the mount).

On this dual rig config, the pixel scale of PHD2 will be smaller ( 0.8″/px ) and there we could see all the real potential of the mount, with 35kg on it and shooting on the the RC at 0.49″/px.

Last sentence is to state a deep thank to Lucas & co for their full support and total availability on my adventure. To understand on all my problems and find the best solution.

I’ll keep you updated!!

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