Waiting the new Mesu200 (mk2?)

[Jonk]

Latest from Modern Astronomy is that pricing will be added to the website, maybe as early as next week.

[Davey-T]

Guess you only need to make one cut at the right angle then rotate it 180 degrees and weld it.

Dave

[Jonk]

1 cut at 22.5 degrees and one at 2.965 (to be close to exact) degrees!

Then rotate and weld, yes.

[carballada]

Ok, lest do a small update.

At the moment only the video of the event 😀

Soon I will publish my first impressions and details.

 

[vlaiv]

23 minutes ago, carballada said:

At the moment only the video of the event 😀

Soon I will publish my first impressions and details.

Brilliant!

Please do include as much info as you can on mount mechanics / behavior.

[Jonk]

Now I have watched that it is very clear that my observatory also needs a bed!

Seriously though, thanks for the vid and good luck with it, I'm sure I'm not alone in waiting for positive reports.

[carballada]

I will explain all the details soon, just I need to write on a understood way 

In the meantime the weather of course, punish me with some delightful fireworks....

 

 

 

Edited August 2, 2019 by carballada

[carballada]

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 Prolific 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 adapter 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. https://postimg.cc/tY4Cjb6v

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!!

 

[carballada]

Now a short video with a slew.

 

It's a temporary set up, waiting the dual rig with an additional RC10

 

please, look how clean is the cable management  

[mrpizza]

Thank you for the review.  My motivation to pull the trigger just went up a few notches since the wedge allows for mounting on existing pier.  Did you order the saddle from Lucas? Was it accessory or did it come standard?  I see the need for that design to take advantage of through cabling.  I look forward to follow ups.

Chris

 

[carballada]

11 hours ago, mrpizza said:

Thank you for the review.  My motivation to pull the trigger just went up a few notches since the wedge allows for mounting on existing pier.  Did you order the saddle from Lucas? Was it accessory or did it come standard?  I see the need for that design to take advantage of through cabling.  I look forward to follow ups.

Chris

 

The saddle is optional and highly recommended in my opinion because it fits perfectly with the new internal cable management.

 

And regarding the wedge, I ordered the wedge for my latitude (it's possible to use it with the Barlebech tripod as example) and an adapter to my pier.

This is what I received (top right: pier adapter)

This is my pier with the Mach1

and the pier with the adapter and the wedge

 

 

 

 

 

 

[carballada]

also another view

[mrpizza]

The setup looks great but I'm sure the pictures don't do justice.  It looks like Lucas went with the original SiTech Telescope Controller I vs the Controller II that was included in the previous version of the mount.  Did he offer a reason for this?

 

Chris

[carballada]

13 hours ago, mrpizza said:

The setup looks great but I'm sure the pictures don't do justice.  It looks like Lucas went with the original SiTech Telescope Controller I vs the Controller II that was included in the previous version of the mount.  Did he offer a reason for this?

 

Chris

You are right, I take pictures to show what I am doing, not marketing pictures

He explain several reasons, but basically it was that servo I it’s enough for manage this mount, it’s cheaper and easy to connect to the computer (he received some complains with the II usb connections) and the connections to the motors and encoders are easy to manage (using rj connector) in a portable setups .

Also I ask for myself on the Sitech forum and this was the answer:

Both controllers use the same operation software SiTechexe.  The differences are :

1. Price

2. Power to servos (Servo 1 is limited to about 2.5 amps, Servo II can handle about twice that.)

3. Processor speed - Servo I can handle mount encoders up to about 1 million tics/rev while Servo II can handle encoders up to 67 million tics/rev

4. Inputs on Servo I are modular cables, Inputs on Servo II are all screw terminals

5. Servo I can connect to PC only with a serial cable (4 pin modular plug) while Servo II can use either serial or USB cable.

6. Servo II has a guide port, Servo I does not but servo I can use a radio handpad to provide a guide port.  Note that a guide port is not needed if you connect the guide camera software to the SiTech mount using ASCOM.

7. The setup software "ServoConfig" are different because the controllers use different processors internally.

I evaluate seriously the option to ask the upgrade to servo II but finally I prefer not to do it, not enough differences because I am interested on PointXP model and home switches and both are possible with my controller.

regarding the esthetics... ok, servo II is much beautiful / industrial finish but I have plan to cover the controller in any case to reduce the dew and dust.

 

[carballada]

First light

SH2-86 Cloud Sculpting Star Cluster (NGC6820-3) in HST

 

all info at Astrobin
https://www.astrobin.com/420032

and Flickr
https://flic.kr/p/2gTvVf1

Edited August 12, 2019 by carballada

[Jonk]

Although your PA is already set well enough for your needs, would you be able to do a video of the PS setting please?

I'm interested to see how it's done with the 3 bolts, especially the drift alignment method rather than with a polemaster.

[carballada]

18 hours ago, Jonk said:

Although your PA is already set well enough for your needs, would you be able to do a video of the PS setting please?

I'm interested to see how it's done with the 3 bolts, especially the drift alignment method rather than with a polemaster.

I did a PA only with Polemaster. After some days I check again the polar alignement with phd2 wizard and here you could see the results.

It's 0.4 arc-min, something that I need to improve with Sharpcap and enough time.

I plan to go to the observatory on the next days to change the counterweight bar and the telescopes adding the RC10 to the current TS107.

After that I will use the Sharpcap routine to find the better PA. I will try to take a video, specially showing Sharpcap routine and how easy (I think) could be the movements to achieve the better PA.

As I told you, the Polemaster alignment was really easy with the three bolts, with very consistent movements to center the the green box and the red circle.

How to explain, did you level a pier base with three bolts? it's a similar process, usually you could push and pull the right bolt to level with no troubles, with that is the same.

Another example could be the collimation process with three bolts in any RC or SC...

[vlaiv]

5 hours ago, carballada said:

It's 0.4 arc-min, something that I need to improve with Sharpcap and enough time.

I would not be too much worried about that. 0.4' PA error will cause max of 0.1"/minute drift rate - that is something that can easily be guided out.

What I am slightly worried about is this:

I would expect less of measured backlash for friction drive and I wonder why is it so?

 

[carballada]

16 hours ago, vlaiv said:

I would not be too much worried about that. 0.4' PA error will cause max of 0.1"/minute drift rate - that is something that can easily be guided out.

What I am slightly worried about is this:

I would expect less of measured backlash for friction drive and I wonder why is it so?

 

graphically is like this (is from the same phd2 wizard session)

I am not really concern (yet) because I need to check again the proper balance on Ra due to my problems with the counterweight bar, or could be something related to the seeing (test was done with 2sec when usually I use 10sec or 15sec for guiding). Anyway on the last pic.. I prefer the red line than the white, seems better? 😀

Due the nice moon, last two nights I run several long Pempro test that I am working on Pempro log viewer.

If the weather allows, tonight I plane to do a long run phd2 wizard (with 10s frames) and another long run without guiding to analyse too.

And I am thinking to concrete plans next 15th to go to the observatory and do the full mount load with the dual rig.

All these previous test are ok, but the real ones will come with full load.

Edited August 11, 2019 by carballada

[Jonk]

On 10/08/2019 at 16:32, carballada said:

How to explain, did you level a pier base with three bolts? it's a similar process, usually you could push and pull the right bolt to level with no troubles, with that is the same.

Another example could be the collimation process with three bolts in any RC or SC...

Yes, the same method also applies to a newtonian mirror which I have done countless times - I was more interested in seeing drift aligment using 3 bolts, as that is likely to be what I end up having.

I don't plan on using a polemaster and have tried a lot of software PA routines, but for me, nothing beats pure analogue drift aligment without software errors to worry about.

Vlaiv is right, the backlash reading seams odd (1/4 of a second?), so unless you have slippage, that could be software not telling the truth, or maybe the motors aren't responding quick enough to the command?

Good luck with your dual rig tests, I'll be watching for the report!

[carballada]

1 hour ago, Jonk said:

Yes, the same method also applies to a newtonian mirror which I have done countless times - I was more interested in seeing drift aligment using 3 bolts, as that is likely to be what I end up having.

I don't plan on using a polemaster and have tried a lot of software PA routines, but for me, nothing beats pure analogue drift aligment without software errors to worry about.

Vlaiv is right, the backlash reading seams odd (1/4 of a second?), so unless you have slippage, that could be software not telling the truth, or maybe the motors aren't responding quick enough to the command?

Good luck with your dual rig tests, I'll be watching for the report!

Thank you Jonk, I am agree with you and Vlaiv I need to do more test with the backlash and see what happen.

Regarding the PA, I am afraid that if you want to use the phd2 drift alignment process is not the best tool to choose because these 3 bolts, that's the reason to use Sharpcap. As you could imagine, with three bolts you never are moving the mount in one axis, only with the top bolt on Altitude. Still If you want to do only the alignment with phd2 drift routine probably it's necessary to do more iterations due this movement in Altitude when you try to adjust your Azimuth with the two bolts on the bottom. When I did the Polemaster routine I saw clearly how the two lower bolts move the alignment point in 2 axis.

But, what I saw is a really good results with Sharpcap.

Of course, at the end I could check the PA with drift routine in phd2 or the phd2 wizard. Also with the PointXP modelling is possible to obtain the accuracy of your PA. 

My plan is to record a PA routine with Sharpcap and I could add the results with the phd2 drift, maybe a super-fine adjustment could be done with phd2 but probably it will need to much time for not to much benefit in my case. Will see in three nights.

 

[kirkster501]

Mine has sat permanently in my obs and run perfectly for the last two years.  It currently has the Meade 14" ACF and TEC 140 in a side-by-side arrangement.  Very heavy approaching 100kg with counterweights.  Seems fine for visual and imaging.

Some day I hope to have two mounts in my obs so I can do two different things.  Would I buy another Mesu 200?  Yes.

[billdan]

This is the backlash I'm getting with the Mesu 200 Mk1, which is very low. You may want to check your DEC balance and make sure its OK.

 

[carballada]

4 hours ago, billdan said:

This is the backlash I'm getting with the Mesu 200 Mk1, which is very low. You may want to check your DEC balance and make sure its OK.

 

Thank you, I'll do this check, sure!!

[carballada]

4 hours ago, kirkster501 said:

Mine has sat permanently in my obs and run perfectly for the last two years.  It currently has the Meade 14" ACF and TEC 140 in a side-by-side arrangement.  Very heavy approaching 100kg with counterweights.  Seems fine for visual and imaging.

Some day I hope to have two mounts in my obs so I can do two different things.  Would I buy another Mesu 200?  Yes.

Exactly for that reason I want a Mesu, not limited weight capacity and really good guiding!  my plan is set less weight, a RC10 and TS107.