Mesu 200 mount

[astrocatinfo]

Good morning,

 

I am doing a bit of research on this mount in order to make a decission on my "mount upgrading". I have been using a tunned Neq6 pro II for a couple of years and now I want to upgrade to a premium mount for better accuracy, tracking, PE, payload, etc.

 

What are your thoughs on it? Some questions:

 

Is it esy to be fully computer controlled?

Has it got a multiple star alignment procedure? I don't see Polaris.

What about the GOTO precission? Anybody knows the arcmin precission?

 

I am also looking for picture with the exact dimensions in order to know how I will deal with it in my observatory.

 

Thanks in advance for your help,

 

Aleix

[swag72]

If you want to see a Mesu in the flesh and fancy a drive south then you are more than willing to come and see mine

[astrocatinfo]

Thanks Sara!! Your work is the best demostration that the Mesu can perform perfectly ;-) I will also use my FSQ85 on it. In my case I plan, in the future, to attach it to a 10" RC or DC... we'll see.

 

Do you know the lenght of the counterweight bar? I have to figure out if it propperly fits my observatory. It has a base of 140x140cm and 190cm tall. The mount just in the center.

 

Thanks so much!

[ollypenrice]

Since Lucas Mesu fitted the SiTech system to replace the Argonavis/Stellarcat system which I have on my older version the mount can be used in fully remote mode. I host one in our robotic shed, in fact.

Since I operate mine myself from a warm room I'm happy with the older system but the SiTech should do what you want it to do.

I regard our Mesu as not only the best mount I've ever used but as the best single piece of kit I use in astrophotography. It has worked flawlessly with a 14 inch scope at 0.66"PP and continues to work flawlessly with our dual Tak 106 rig.

If you let me know exactly what dimensions you need I'll be happy to go and measure up for you. Ours stands on a Mesu pier. The telescope part of the roll off observatory is 2.2M square which gives comfortable access right around the scope for imaging purposes but you would want more to use it visually. The wall height is 1.3 metres. We have dark horizons so I made the upper sides of the observatory roll off with the roof. Internal roof height is 2 metres which allowed the 14 inch ODK to go to any position without collision.

In our purely robotic roll off we used a 1.6M square floor plan which clears a 10 inch RC in all directions, just. Access is 'daytime only'.

Olly

[astrocatinfo]

Thanks Olly for the detailed information. Looks that this mount can perform perfectly and with accuracy. 

One of the mesures I would need is the counterweight bar lenght. Do you know it?

 

Thanks,

Aleix

[ollypenrice]

7 minutes ago, astrocatinfo said:

Thanks Olly for the detailed information. Looks that this mount can perform perfectly and with accuracy. 

One of the mesures I would need is the counterweight bar lenght. Do you know it?

 

Thanks,

Aleix

The stainless steel shaft extends beyond the mount castings by 45cm but the distance from the Dec drive wheel housing to the end of the C/W bar is 71cm. We did use a longer one once while experimenting with a huge dual rig.

Olly

[astrocatinfo]

Thanks Olly!

 

If I understood well it's 71cm from the axe or center of the mount (DEC Wheel)?

My observatory has a surface of 140 x 140 cm and a height of 190cm. Will it fit? I leave some photos to clarify the volumes. The pier is 140cm tall (pier + Eq6 minipier).

 

Thanks so much for your help.

 

Regards,

 

Aleix

[ollypenrice]

At my latitude (44N) it seems from an approximate measurement that my setup is oprating within a cylinder of radius 56cm.

Here's the setup.

As it stands the widest item defining the 'operating cylinder' of r=56cm is the counterweight bar. From your more southerly latitude this would be a little wider but not by much. Leaving room for the cables exiting the back of the camera the rear of the scopes also need about 56cm radius. The front end of the scopes needs a few cm less. 

So a lot depends on your scope length. I'm sure Lucas could make you a shorter CW bar on which you'd add an extra weight if necessary, but the Tak 106 is a short scope. A longer one would need a larger operating cyclinder, of course. However, with a full roll off you don't need an 'operating cyclinder,' you only need to be able park the scope, in which case the C/W bar is probably your limiting factor.

The bottom line is that, with a custom CW bar, I can't see why the Mesu should take up more room than the EQ6.

Olly

[astrocatinfo]

Thanks again Olly for your keen help.

When arrived at that point I'll talk to Lucas Mesu to set the sizes.

Regards.

[astrocatinfo]

Nice setup indeed!! Two Taka's on a Mesu. Wow!

About the "operating cylinder" just say that I have all the space I want. The "house" that covers the mount-scope has wheels, so it moves to leave the setup uncovered. I just have to figure out what's the limit size for a scope to fit there. I think the limit will be an 12/14" OTA (RC).

 

Regards,

 

Aleix

[kirkster501]

Original poster, forgive slight thread hijack.

Olly, what is going on with the FSQ nearest the camera in your picture please?  How may saddles and whatnot...???!!!!!!

You've got a large silver Losmandy Dovetail (it appears?) screwed on the mount plate (with another silver spacer of of some kind?) then two Losmandy saddles for both scopes bolted onto that silver bar.  Then, in the one nearest picture seems to have two additional saddles..... Is that a tilting mechanism to get the two scopes aligned on the same object?  If so how robust is that?

Also, what is that tube thingamabob with the gold top underneath the mount plate?

Appreciate a run down on how you have done this?

You've got about £1000 worth of saddles and bars in that set up!

Back on topic, Lucas is behind schedule on his current production due to there being a delay in his suppliers of the high quality metals he uses run and I wont get mine now until at least mid January   Would not be a problem but I have sold my lovely NEQ6 now in anticipation! That NEQ6 never missed a beat!

So my lovely FSQ85 and TEC are mothballed and it's visual with the Dob for a month at least!

[Zakalwe]

Its a Robin Cassidy tilt plate isn't it?

http://www.robincasady.com/Astro/TGAD.html

 

The tube is the DEC motor.

[ollypenrice]

3 hours ago, kirkster501 said:

Original poster, forgive slight thread hijack.

Olly, what is going on with the FSQ nearest the camera in your picture please?  How may saddles and whatnot...???!!!!!!

You've got a large silver Losmandy Dovetail (it appears?) screwed on the mount plate (with another silver spacer of of some kind?) then two Losmandy saddles for both scopes bolted onto that silver bar.  Then, in the one nearest picture seems to have two additional saddles..... Is that a tilting mechanism to get the two scopes aligned on the same object?  If so how robust is that?

Also, what is that tube thingamabob with the gold top underneath the mount plate?

Appreciate a run down on how you have done this?

You've got about £1000 worth of saddles and bars in that set up!

Back on topic, Lucas is behind schedule on his current production due to there being a delay in his suppliers of the high quality metals he uses run and I wont get mine now until at least mid January   Would not be a problem but I have sold my lovely NEQ6 now in anticipation! That NEQ6 never missed a beat!

So my lovely FSQ85 and TEC are mothballed and it's visual with the Dob for a month at least!

'You've got about £1000 worth of saddles and bars in that set up!' And the rest! Tell me about it...  Mercifully some bits were beta testing items and the rest were second hand.

So the side by side bar in plain alloy is by Robin Casady and is intended for heavy scopes side by side. You could use a standard long Losmandy but it might not be stiff enough. At the far end, carrying the more distant scope (Tom's), is a short Robin Casady dovetail clamp holding an ADM Losmandy plate to which the tube rings are fastened.

The near scope (mine) rides on a blue Altair Astro Losmandy plate and attaches to the big alloy side by side bar via (as Zakalwe says) a Robin Casady T GAD tilt-pan adjuster. This is a fatastic device, brilliantly conceived and constructed but now out of print, so to speak. Fortunately Yves chanced upon this one second hand in the Netherlands and grabbed it for me. Even so the Cassady stuff came to 6OO euros. (Monique does not read SGL...) http://www.robincasady.com/Astro/TGAD.html  It allows precision, long lasting alignment of the two scopes and, believe me, this is very necessary. It is also stiff enough not to allow any differential flexure between the 'guided' and the 'slave' scopes. The downside is forking out 600 euros for an adjuster which works so well that you only use it once... FLO now offer a similar device. 

Guide rings are Altair Astro. I don't normally use guide rings but these are good ones. (We had an unresolved query over whether dual rigs like the guider to be centred with the imaging scopes. We played it safe and did align the guidescope, though I never do so on single rigs.)

I think the thingumabob is the dec motor?

And finally, in this quirky setup, there's the home made microfocuser on my scope. Tom hates it. I love it! It is by far the best microfuser I've ever used and it cost about 2P. You can see how it works here. The smallest turn you ever make is 180 degrees and that is a tiny movement for the draw tube. It also holds the position against sag.

Quirky or not, this rig is fast, easy, reliable and really does knock out data. The Mesu lies at the heart of it and 'just does it.'

Apologies for the digression, Aleix.

Olly

[kirkster501]

https://www.firstlightoptics.com/adm-losmandy-type-d-series/adm-losmandy-style-dual-mounting-bar.html

i think this is the FLO ADM version Olly refers to.

Sorry for hijacking your thread OP. 

 

[steppenwolf]

On 04/12/2016 at 10:12, astrocatinfo said:

Is it esy to be fully computer controlled?

I am a little late to this discussion but I have a fully automated observatory and a Mesu mount at the heart of it. The SiTech controller makes this mount very easy to operate either remotely or automatically. Although there is plenty of information that won't be directly of relevance to you, you may find it worth having a look at my automation thread here for some insight into the automation of the Mesu mount.

 

 

 

[astrocatinfo]

Thanks Steve! I appreciate your feedback. I won't be using remote right now but yes in a near future. Now just automatic use from inside home.

 

Thanks to all of you!

[iansmith]

I have been using a Mesu 200 since June this year and am really happy with it.

I have a Edge 11 mounted with various cameras and associated equipment and it handles all this with ease. I control my observatory from the house, so it is remote (if 6 foot from the back door counts as remote!) and was easy to set up. The mount has worked without problems being guided by PHD2 and also controlled by SGPro, both via ASCOM. PHD2 routinely reports a guide RMS of approx 0.5" which I think is pretty good considering the 2.8m focal length I'm imaging at.

My only quibble with it is that with such a heavy scope it can be hard to make fine adjustments for polar alignment, but this can be overcome by either using a smaller scope for PA or use something to give you more leaverage when turning the axis adjustment knobs. Having said that I got my PA to about 1' which is plenty good enough.

when I was thinking of buying the scope I found Modern Astronomy to be very helpful, answering my questions on dimensions and so on.

Cheers, Ian

 

[ollypenrice]

 

2 hours ago, iansmith said:

 

My only quibble with it is that with such a heavy scope it can be hard to make fine adjustments for polar alignment, but this can be overcome by either using a smaller scope for PA or use something to give you more leaverage when turning the axis adjustment knobs. Having said that I got my PA to about 1' which is plenty good enough.

 

Cheers, Ian

 

Ian, we found the adjusters worked superbly when doing PA with a 14 inch ODK. I wonder if all you need is a drop of lubricant, not that we applied any. In fact our PA experience was slightly surreal: I aimed at Polaris by naked eye and we went to the south for a first drift iteration, which we performed over about a five minute run. We made a second adjustment in Azimuth and sat back. Five minutes went by, ten minutes went by, and the star didn't budge. I remember Yves and I looking at each other and wondering what we were missing. So we went off the the east and exactly the same thing happened. Two iterations and the job was done. Pure fluke, mostly, but the adjusters really did work sweetly.

Olly

[iansmith]

Thanks for the tip Olly, I will remember that for the next time I need to adjust the PA. So far it seems to be holding it pretty well so it maybe next summer before I get round to doing that!

Cheers, Ian

 

[astrocatinfo]

It looks promising. Today I am at my observatory and I'll mesure exactly all the dimensions of it. I want to make sure that the Mesu fits and how tall has the pier to be.

 

In a short time a full equiped and tunned NeqproII + pier will be for sale

[ollypenrice]

26 minutes ago, iansmith said:

Thanks for the tip Olly, I will remember that for the next time I need to adjust the PA. So far it seems to be holding it pretty well so it maybe next summer before I get round to doing that!

Cheers, Ian

 

Ours tends to last about two years. We have the Mesu pier with adjustable feet but it has straps which hold the feet down firmy onto the floor.

Olly

[swag72]

There's two points about this mount that I don't really like...... no that's too strong.... One thing that irks me a little and one thing that bugs me quite a bit.

I don't like balancing the mount...... I much prefer the instant feedback of a de-clutched mount that can move freely. The balancing is something of guess work in a way and I don't really like that. The second thing is Polar alignment. I find this a particular chore.... the single bolt that holds the mount into the mount plate seems to allow considerable movement when tightening up after getting the polar alignment just right. I find this very frustrating indeed.

But neither of these things has actually affected the accuracy of the mount for guiding as far as I can tell... they're just things that I don't really enjoy about an otherwise excellent mount

[iansmith]

2 minutes ago, ollypenrice said:

We have the Mesu pier with adjustable feet but it has straps which hold the feet down firmy onto the floor.

Olly

I have the Mesu pier with adjustable feet, but I haven't strapped them down. I built some wooden "shoes" that go round the feet and are fixed to the observatory floor. Stops me from knocking the mount out of alignment when I have to go in to open/close the roof and turn everything on and off.

8 minutes ago, astrocatinfo said:

It looks promising. Today I am at my observatory and I'll mesure exactly all the dimensions of it. I want to make sure that the Mesu fits and how tall has the pier to be.

 

In a short time a full equiped and tunned NeqproII + pier will be for sale

Good luck, I still remember the joy of zero backlash when I first got my Mesu

Cheers, Ian

[ollypenrice]

1 hour ago, swag72 said:

There's two points about this mount that I don't really like...... no that's too strong.... One thing that irks me a little and one thing that bugs me quite a bit.

I don't like balancing the mount...... I much prefer the instant feedback of a de-clutched mount that can move freely. The balancing is something of guess work in a way and I don't really like that. The second thing is Polar alignment. I find this a particular chore.... the single bolt that holds the mount into the mount plate seems to allow considerable movement when tightening up after getting the polar alignment just right. I find this very frustrating indeed.

But neither of these things has actually affected the accuracy of the mount for guiding as far as I can tell... they're just things that I don't really enjoy about an otherwise excellent mount

I agree abut balance, though just doing it by feel has always proved satisfactry for me.

Regarding the PA shifting as it's tightened down, I've never found this. On the Mk1, at least, you have big finger-type nuts on both sides to move the mount in Alt and Az. I keep all the locking nuts on the firm side even when moving the alt or az adjusters and then I firmly finger-tighten both the lock nuts on each adjuster before clamping the main locknuts.

Olly

[kirkster501]

5 hours ago, swag72 said:

There's two points about this mount that I don't really like...... no that's too strong.... One thing that irks me a little and one thing that bugs me quite a bit.

I don't like balancing the mount...... I much prefer the instant feedback of a de-clutched mount that can move freely. The balancing is something of guess work in a way and I don't really like that. The second thing is Polar alignment. I find this a particular chore.... the single bolt that holds the mount into the mount plate seems to allow considerable movement when tightening up after getting the polar alignment just right. I find this very frustrating indeed.

But neither of these things has actually affected the accuracy of the mount for guiding as far as I can tell... they're just things that I don't really enjoy about an otherwise excellent mount

You need to deploy "Steve tightening".  It will never move again Sara, rest assured.  No one can get jar lids off in our house....

On a more serious note, how do you balance it then?