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Mount for 16" SCT

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#1 Tuugii

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Posted 07 October 2012 - 04:07 PM

Dear people,

I am starting a project to fix a Meade 16" SCT telescope in Mongolia. The telescope was originally donated to Mongolia almost 10 years ago from the Lunar Planetary Laboratory at the University of Arizona. They we're planning to use it for follow up photometric monitoring of asteroids.

Unfortunately few months after the installation it was struck by lightening and now when you turn it on the mount starts moving by itself, totally uncontrollable. We have called the 'best' electrical engineer in Mongolia and disassembled everything, didn't find anything burned or obviously damaged, so put it back together, but still doing crazy stuff when turned on.

So we decided to replace the whole mount. It was originally installed with the Meade fork mount on a permanent pier. Couple of days ago I gave a call to Meade, but they have told me that they don't sell mounts for 16" separately... so I am looking for other solutions.

Do you guys know anybody planning to sell his or her Meade fork mount? (I guess its very unlikely) or do you have any suggestions on what kind of mounts we shall purchase?

Any inputs would be greatly appreciated!
thanks,
Tuguldur

#2 Tuugii

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Posted 07 October 2012 - 04:52 PM

The telescope OTA weight seems to be around ~60lb. So far I have found following 2 options:

AP 1600GTO GEM
Takahashi EM500

Anybody has suggestions on how to install the telescope on the GEM? I am guessing we need few solid dovetails?

#3 JoseBorrero

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Posted 07 October 2012 - 05:52 PM

They have been some months ago were on Amart they got for sale 16"LX200 mount without OTA. Is never bad to post it on Amart and see impressive result in such community.

#4 Mkofski

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Posted 07 October 2012 - 06:39 PM

There are at least 2 mounts made in Euorpe that would handle a 16" SCT. One from France you can see at http://www.skyvision...-mount/?lang=en

I'll see if I can find links to some others. These are WAY out of my budget so I'm not real familiar with them. Very expensive options I believe.

#5 Griffin!

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Posted 07 October 2012 - 07:07 PM

There are also the ASA mounts if you're looking for something in Europe.

#6 Mkofski

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Posted 07 October 2012 - 07:16 PM

The MI500 or MI750 would handle a 16" SCT.

http://www.mathis-in...com/prices.html

Have you talked to Meade about repairing your current mount. That may be less expensive than a new mount.

#7 orlyandico

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Posted 07 October 2012 - 07:22 PM

In theory you could replace the Meade mount motors with stepper motors and use something like this...

http://teleskopsteue...dex.php?cPath=1

I am far from the 'best' electrical engineer at anything but that's the path I took...

#8 frolinmod

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Posted 08 October 2012 - 01:24 AM

If I were you, I'd get either a Software Bisque Paramount ME II mount (best) or an Astro-Physics AP-1600 mount (second best). I would not settle for less.

#9 Tuugii

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Posted 08 October 2012 - 04:27 AM

Thank you very much everyone for replies! these are very helpful.

just as a note, shipping from U.S. to Mongolia through China turns out to be cheaper than shipping from Europe to Mongolia; even though the latter is a shorter geographic distance.

Meade could probably fix the mount, unfortunately as far as I understood the factories that do provide such services only located in U.S. So shipping the broken mount to U.S. and shipping back after fixing would cost way more than a new mount. We also don't have any guarantee that the Meade factory will be able to fix the issue, not to mention for a lower price.

So basically I think I will have to buy a mount from U.S. or Japan. AP 1600 GTO is certainly one of the top choices, and I have sent them an email for an estimate. I will also look into EM 500 if they have any available to ship straight from Japan to Mongolia.

The question now arising is, how people attach SCT's to the GEM? I am guessing through dovetails? I think similar large aperture celestron SCTs come with the dovetail, but has anybody tried attaching large Meade SCT to the GEM?

#10 frolinmod

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Posted 08 October 2012 - 05:09 AM

Attach the OTA to the mount with either an Andy Homeyer Scope Cradle (best) or Parallax rings (second best).

#11 Awesomelenny

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Posted 08 October 2012 - 10:21 AM

Hello Tuguldur,

I had the same dilemma as you with my Meade 16" LX200GPS. The electonics on the forks are very delicate. The slightest electrical short will just ruin them.

Meade has a horrible policy regarding selling parts. I am convinced that their belief is that the public is dumb and would not know what to do to fix their equipment. But that is only my opinion.

After having the electronics go bad twice, I gave up on Meade for repairs. I sold off the forks and purchased a used Astro Physics AP1200 mount. That mount was superb and had no problems carrying my 16 Meade along with a Takahashi FSQ 106 riding atop it.

As for mounting, I used the AP saddle (DOVELM162)
and a Losmandy dovetail with Parallax Rings.

The tracking was just impeccable with that mount. Today the AP1600 would easily handle this!

#12 EddWen

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Posted 08 October 2012 - 11:34 AM

I have a 400 mm Mak-Cass-Rumak which weighs 52 Kg mounted on an Astro-Physics 1200GTO. Works well for visual, but I cannot speak of imaging, as I don't image.

Here is a picture that shows the relative sizes.

Good luck!!

Attached Files



#13 lambermo

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Posted 08 October 2012 - 02:37 PM

Tuguldur, feel free to use my list of mounts and look for those with payloads over 50 kg.

#14 Tuugii

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Posted 14 October 2012 - 04:13 AM

Guys, thank you very much for your replies again! especially lambermo, that list was very useful!

I have one last thing to ask you all. I recently found out that before even the lightning strike, the mount's (original Meade fork that comes with 16") servo motors had some issues with the very cold temperature of Mongolia. At the observatory it gets down to below -40C easily during the winter times (oct-mar) and we want to make sure our new equipment survives this climate.

Anybody has any experience using AP1600GTO or other mounts in very cold temperatures?

thanks,
Tuguldur

#15 orlyandico

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Posted 14 October 2012 - 04:40 AM

There are AP900 1200 and 3600 in Antarctica. You need to order them from AP with a special low temperature grease.

http://www.company7....nts/900gem.html

#16 Tuugii

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Posted 14 October 2012 - 03:11 PM

Wow that is really cool! so I should not be worried about that.

I have been in touch with a guy from AP and he has told me that I need following items in order to use the mount with the 16"SCT. What do you guys think? anything missing or anything extra?

German EQ mount with low-T grease (AP1600GTO)
$12,800
Dovetail plate (LMDM16)
$330
Saddle (DOVELM162)
$265
Power Supply (13.8V DC)
$65
Adapter to Pier (1612FSA)
$154
Counterweights (4 x 18 lb)
$760
Shipping (DHL estimate for 200 lb box)
$~700

I can afford few extra things if they're really necessary, but the most important thing is I need to have literally everything, all small pieces, parts and bolts with me there next summer. It is hard to find things in Mongolia, so if I don't have everything with me it might delay the work significantly.

thanks,
Tuguldur

#17 orlyandico

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Posted 14 October 2012 - 07:19 PM

wouldn't you also need Parallax rings or something?

I don't see how you could attach the dovetail plate to the Meade 16" OTA..

#18 Tuugii

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Posted 14 October 2012 - 08:44 PM

wait I have double checked everything, and it seems like that Losmandy Dovetail has radius blocks on it so it attached to the scope directly.. I am not 100% completely sure..?

#19 TxStars

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Posted 14 October 2012 - 10:21 PM

Using the radius blocks and dovetails seems like a lot of weight would be held with small screws and an aluminum casting.
I would opt for the Parallax rings with dovetails to increase the stability of the scope.

Only down side is added weight, not that it would be a problem for the AP1600 mount.

#20 Christopher Erickson

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Posted 14 October 2012 - 11:21 PM

One of my observatory clients has a set of brand-new Software Bisque TCS motors and GOTO electronics left over from an upgrade project that changed direction mid-stream. If you are interested, send me a PM and I'll put you in touch with them. That would allow you to retrofit the mount you already have with new Software Bisque motors and electronics. Some minor machining for new motor brackets and such would be required.

They decided to go with the Sidereal Technologies servo motors and GOTO system instead, and that is also an option for you.

Both the Software Bisque and Sidereal Technologies GOTO systems use servo motors, which I believe are greatly superior to stepper motor solutions.

At any rate, either solution would be a much cheaper and more painless upgrade path than replacing the entire mount.

I hope that helps.

#21 Christopher Erickson

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Posted 15 October 2012 - 12:29 AM

Using the radius blocks and dovetails seems like a lot of weight would be held with small screws and an aluminum casting.
I would opt for the Parallax rings with dovetails to increase the stability of the scope.

Only down side is added weight, not that it would be a problem for the AP1600 mount.


I have used radius blocks on Meade 16" SCT's a fair number of times without incident. There are threaded holes for them already in the OTA. It makes for a very strong mounting solution. The Astro-Physics and Losmandy radius blocks and dovetail bars for Meade's 16" SCT's are big and beefy.

Be advised that the Classic LX200-16 OTA's are slightly longer than the LX200GPS-16's and the dovetail bars are different lengths. The radius blocks are the same. Make sure to get the right bar.

If you have a Classic LX200-16, you also have the option of sending your existing electronics to Ron Sampson in the USA for repair. Ron has been repairing the electronics for the Classic LX200's for a fair number of years and a typical repair is about $350, the last time I checked. Ron does not have a web site but he can be reached at rsampsonus@yahoo.com

There is also a Yahoo group dedicated to the LX200-16 scopes (both Classic and GPS) and you might benefit from checking it out.

http://tech.groups.y.../group/16-LX200

The Astro-Physics 1200GTO and 1600GTO are both excellent mounts and you wouldn't go wrong with either of those choices. Astro-Physics has top-notch customer support and they will sell you whatever parts you might need in the future.

I am not a fan of Software Bisque Paramounts. Proprietary software and proprietary/undocumented serial commands.

If you go with a GEM mount, I would certainly use radius blocks and dovetail bars instead of going with rings.

I hope this helps!

#22 Tuugii

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Posted 15 October 2012 - 01:05 AM

Chris, thank you for the suggestion. But in the meantime I think a new mount is the way to go. (I have already submitted the proposal)

But there are couple of other equipments where in the future we could do upgrades as you're suggesting. I will let you know!

TxStars, thats what is feels like I agree with you. But those small bolts and screws could be just fine, check the attached picture, it shows the 16" sct ota on the fornax mount.

Attached Files



#23 Tuugii

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Posted 15 October 2012 - 01:16 AM

Dear Chris, we will fix that old fork mount eventually and will try to make use of it. It's issue with the 16" OTA is not just the damaged electronics but it just not suited for operation in cold weather. As I mentioned previously, even before the lightning strike its motors were acting weird. Plus we have tried sending the motors to U.S. for fixing, but without any success.

There are couple of old russian otas of ~12" size, where we could use the fork mount in the future for just public EP viewing. I will definitely keep in mind your suggestions on that.

And thanks for the heads up on the difference between the classic and gps versions of the 16". Ours is about 10 years old, I am sure it is the classic one.

#24 TxStars

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Posted 15 October 2012 - 08:35 PM

TxStars, thats what is feels like I agree with you. But those small bolts and screws could be just fine, check the attached picture, it shows the 16" sct ota on the fornax mount.


If you look close at the picture you will see that they used "Rings" on the 16"

#25 David Pavlich

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Posted 15 October 2012 - 09:32 PM

I have to agree with the rings. I did this for a C14 for the added stability, not to mention that loading it into the "cradle" that having rings on the mount opened up becomes sure makes installing the scope easier.

David






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