Mesu200 mk2 as my travel mount?

[matija]

Hello!

 

I've had an EQ8R for a while now but I want to upgrade as the guiding performance is not good enough for my 2000mm telescope.

A while back I came across mesu200 while browsing some stuff for my other big telescope that uses SiTech, and it got me thinking.

Is the mesu200 easy enough to polar align from scratch every night? I can get within a few arcmin with a laser but then its onto the screws. I've been traveling with the EQ8R for over a year now so I'm used to the weight(I think the mesu is even lighter).

 

My only real concern is the polar alignment and maybe balance. Can it be done quickly?

Thanks!

Matija

[Elp]

This is down to you. Credit to you if you consider an eq8r as travel friendly, if it works for you then it's okay. I personally don't consider mounts above a 12-14kg payload as travel friendly, especially if they need counterweights.

Regarding your alignment question, I setup and breakdown pretty much every session and alignment and balance probably takes up 10 minutes of time, so not much at all. Physical setup from fresh takes around 20 minutes and add another 10-15 for focus routine, guiding calibration and plan setup. So just under an hour, if the rig is already pre setup from a previous night we're around the 20-30 minute mark before imaging go time.

[matija]

@Elp

Thanks for the reply,

Yeah, I don't mind the wight.

Do you use the 3 screws on the canter of the wedge to PA? And what software do you use?

Thanks!

[Elp]

I don't have either mount but with my gem28 in its closed position so it fits into its flight case I know it takes around 12-13 half turns of the altitude adjustment knob using the Allen key to do the half turns and it pretty much gets the altitude very close. Azimuth is done with the built in knobs. It's very easy to PA my gem28. My hem15 is already set at altitude as it's small enough to store like that but due to its construction takes slightly longer to PA than the gem28. My azgti is quick to PA because I'm using a William optics wedge which is quite precise in its thread machining so altitude and azimuth are quite easy to adjust.

The time all depends on how well the product is put together, Ive read mesus are extremely good but note the weight of the 200 head alone is something like 25Kg, more weight may take more time to adjust just because you're being more careful, but will likely allow for more precision like I experience with my gem28 compared to the lighter setups so in fact may end up being quicker to do. I'd anticipate the mesu being very precise to setup and operate.

If you consider a full (HD motors on both axis)  harmonic drive mount you don't even need to balance the RA and DEC, if you're within the non counterweight payload you don't need counterweights either.

I use an Asiair, it's PA routine is extremely easy and quick to follow, and all you need in addition with you is a mobile phone and power bank (you can even use a usb power bank for the asiair mini). It's better than PHD2 and ioptrons ipolar software from experience trying them both, though I still reserve judgement on how accurate its PA figures are, it's never caused star trailing issues when imaging which is the most important factor, the convenience factor of carting around less equipment is the main consideration for using it.

Edited August 29, 2023 by Elp

[ollypenrice]

I've polar aligned the original Mesus several times and a guest brings one here every year. However, these are not on the angled pier, which has a limited latitude range, I presume. Which one are you using?

Alignment is, in my view very easy. The Alt-Az adjustments bolt are beautifully made in stainless steel and are hefty and free from flex. Our guest just uses the Mesu polar scope, which is actually the Losmandy optical tube on a Mesu bracket which simply bolts on and off. He says it works fine and is all he uses. No need for drift refinement.

I've never had any issues with balance. I have no clutches but it doesn't seem to matter. Just balancing by feel has always worked fine. My oldest Mesu has the proud boast that it has never, ever,  lost a sub to guiding error and that's in commercial use over a ten year period.

Olly

[matija]

@ollypenrice,

I'm looking at the Mesu200 variant that has three screws in the middle of the angled wedge. No other form of PA. Is it still easy in that case?

 

Matija

[ollypenrice]

48 minutes ago, matija said:

@ollypenrice,

I'm looking at the Mesu200 variant that has three screws in the middle of the angled wedge. No other form of PA. Is it still easy in that case?

 

Matija

I'm afraid I don't know. I've never seen one of these. Lucas Mesu is an excellent engineer, however.

Olly

[tomato]

I set up and took down a Mesu 200 Mk 1 for 5 years before building a permanent observatory. Note the Mk 1 has more user friendly alt/az adjustment than the Mk 2, which I think is designed to be used with a dedicated 3 bolt wedge, I can’t comment on how easy this is to adjust.
I always put the tripod in the same place and could polar align with Sharpcap in about 10 minutes.

Putting it up was always OK (motivated by the imaging session to come) but taking down at 2 or 3 in the morning when I was cold and tired was getting a bit of a bind.

[matija]

@tomato Yeah I'm looking at the mk2 as i'm buying new. The bolt system scares me a lot.

 

[Elp]

This offers some insight:

https://www.cloudynights.com/topic/779640-mesu-200-mkii/

[dan_adi]

On 29/08/2023 at 13:08, matija said:

Hello!

 

I've had an EQ8R for a while now but I want to upgrade as the guiding performance is not good enough for my 2000mm telescope.

A while back I came across mesu200 while browsing some stuff for my other big telescope that uses SiTech, and it got me thinking.

Is the mesu200 easy enough to polar align from scratch every night? I can get within a few arcmin with a laser but then its onto the screws. I've been traveling with the EQ8R for over a year now so I'm used to the weight(I think the mesu is even lighter).

 

My only real concern is the polar alignment and maybe balance. Can it be done quickly?

Thanks!

Matija

If weight is no problem then go ahead. Polar alignment is easy

[Stuart1971]

On 29/08/2023 at 17:24, matija said:

@tomato Yeah I'm looking at the mk2 as i'm buying new. The bolt system scares me a lot.

 

You are not on your own, I think the Mk 2 Mesu, has a pretty poor system for polar alignment, compared to the original, and to other mounts of similar quality, it seems a real shame and IMHO a backwards step.

Have you looked at the JTW Trident friction drive mounts, these are very well priced 75kg payload, and the same PA adjustments as the original mesu…seem to be getting quite popular with more models on the way…

https://www.jtwastronomy.com/products/p75-trident-direct-friction-drive-telescope-mount

also much more user info here

https://groups.io/g/jtw-astronomy-users/topics

Edited August 31, 2023 by Stuart1971

[dan_adi]

22 hours ago, Stuart1971 said:

You are not on your own, I think the Mk 2 Mesu, has a pretty poor system for polar alignment, compared to the original, and to other mounts of similar quality, it seems a real shame and IMHO a backwards step.

Have you looked at the JTW Trident friction drive mounts, these are very well priced 75kg payload, and the same PA adjustments as the original mesu…seem to be getting quite popular with more models on the way…

https://www.jtwastronomy.com/products/p75-trident-direct-friction-drive-telescope-mount

also much more user info here

https://groups.io/g/jtw-astronomy-users/topics

They look like a cool Mesu :). Good to see more adoption of the friction drive. I also like they made a protective case for the motors, I'm always afraid I'll accidentally hit the motors on the mesu.

Looking at the guiding graphs the performance is equal to the Mesu, that's great.

Also I've noticed they recommend lower aggression and longer pause between guiding exposures, and this is what I also noticed with the mesu. Things settle down quite nice if I use 8 sec exposures and a couple of seconds delay

[lrsibb]

On 29/08/2023 at 10:24, matija said:

@tomato Yeah I'm looking at the mk2 as i'm buying new. The bolt system scares me a lot.

 

The Mesu 200 bolt system is excellent. I have used it on both tripod and now observatory settings. Get two reasonably long 19mm wrenches.  

Fine adjustments:  loosen a nut and then tighten the opposing nut - done - repeat as your PA measurement method dictates. The finer the adjustment required, the less loosening / corresponding nut tightening required.

The PA adjustments stay adjusted - separate adjustment/tightening steps that alter PA are eliminated. It is elegant in a completely engineering way. 

 

Edited October 12, 2023 by lrsibb

[tooth_dr]

On 31/08/2023 at 11:49, Stuart1971 said:

think the Mk 2 Mesu, has a pretty poor system for polar alignment

I have a mesu e200 (mark 2) and find the bolt system ok.  Not sure if it’s a backward step - it’s simple and mimics actions like collimation. Using a large 19mm spanner (as said above) it is easy to carry out the slightest of adjustments to any of the six bolts.  I think unless you’ve tried it, then it’s hard to be sure about how good (or poor) something is 👌🏻

My wedge was an off the shelf version made by Lucas as I didn’t want to wait months for a custom one set to my exact location, hence the angle of the mount compared to the wedge.  

Edited October 12, 2023 by tooth_dr

[Stuart1971]

1 minute ago, tooth_dr said:

I have a mesu e200 (mark 2) and find the bolt system ok.  Not sure if it’s a backward step - it’s simple and mimics actions like collimation. Using a large 19mm spanner (as said above) it is easy to carry out the slightest of adjustments to any of the six bolts.  I think unless you’ve tried it, then it’s hard to be sure about how good something is 👌🏻

 My wedge was an off the shelf version made by Lucas as I didn’t want to wait months for a custom one set to my exact location. 

I had a DIY steel wedge just like that for my old fork mounted SCT, 20 years ago and it was a pain to try and adjust on a cold night with spanner’s, it might work well for you but that system on a premium mount is very poor IMHO, the mount “deserves”  a much better system, and it’s certainly a backward step compared to what the MK1 had, especially when you have to pay over £6k.
JTW  have now adopted the old system from the Mk1 mesu, on there new friction drive mounts at a couple of grand cheaper 👍🏻

I realise you have one and I don’t, but the system is identical to what I had….

[tomato]

The Planewave mount (circa £20k) uses a similar bolt system for fine adjustment. I have to say the Mk 1 Mesu with knurled knobs is great for a lightly loaded mount, but when I have upwards of 130 kg all up weight on there I think I would prefer something that used a 19 mm spanner.

[tooth_dr]

@Stuart1971 I'll have to make do with my poorly designed wedge 🤣

 

@matija Is it easy to balance = yes very, it glides effortlessly with the clutches off.  Is it easy to polar align = yes, with Sharpcap Pro software it's is very straightforward.  Would I want to be setting one up each night = no I dont think so.