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Anyone Else Running This Complete Meade/Terabeam?

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#1 CharlesStG

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Posted 04 January 2009 - 01:00 PM

I simply love this Meade/Terabeam complete set-up running the DobDriverII with PC link for full control and remarkable quiet and precision. Wondered if anyone in the world got in on this same set-up when they were available on ebay a few years ago. I'd love to hear from you! The stability of this 30# mount is pretty nice -- on a real sturdy tripod, I can focus at 150X with no image shake at all and even rest my left hand on the top of the scope while observing with no shakes. Hoping to hear from anyone interested in these or any who have the same mount or similar set-up :jump:

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#2 CharlesStG

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Posted 06 January 2009 - 12:13 AM

Second pic attached below:

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#3 GJJim

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Posted 06 January 2009 - 04:00 AM

Enjoy your gadget -- you probably got one heck of a deal. In the late '90s Lucent Technologies invested over $400M in Terabeam, and I'm sure some of that money helped pay for the development of this mount and optics.

#4 CharlesStG

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Posted 06 January 2009 - 08:55 AM

Yes Jim, The R&D for this mount was likely pretty high. I am told by one of the engineers on this Meade/Terabeam joint venture that these gimbal mounts were initially estimated by Meade to cost $8,000. each, but in the end Terabeam ended-up paying $20,000. each for them -- could be cancelling the project forced the amortization of R&D to be covered by only the 100 or so units produced. The OTAs cost Terabeam somewhere between $1200. and $2000. each. I was fortunate enough to have printed out the specs on these mounts a few years ago when I could still find them. One reason for the high cost was that they were built to pass stringent performance specifications for tracking accuracy, stability, etc. Building to a high spec is quite a challenge sometimes. All I can say is these mounts really perform and the drives have so much power that balancing the scope is hardly necessary for most uses. The mounts have fully adjustable stainless steel worm gears on spring loaded gimbals which allow the worms to tilt outward by twisting a motor which, in turn, allows immediate pointing of the scope to anywhere you like in Alt and Az. I haven't seen anything other than professional astronomy gear which performs like these mounts -- even my A-P 400 mount was wobbly by comparison though I did get the vibration settling time on the A-P down to less than a second. There is no settling time on the Meade mount - it never vibrates at all when focusing or even resting one's hand on the OTA at 150x. Hope to find a few others here who managed to get them working once they acquired them back in late 2004 when they became available for sale to the public.

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#5 Michael Miles

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Posted 09 January 2009 - 11:50 AM

How much did you pay for yours?

Michael

#6 CharlesStG

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Posted 09 January 2009 - 03:50 PM

A bit more than the ETX-125ATs I just bought - lol. Just had a private inquiry from a gent who agreed it was worth as much as a new Questar 3.5 package - and then some. Terabeam paid over $20K. The OTAs are available quite often, but the mounts are simply "gone" - haven't seen one for sale in over 2 years. When they were selling on ebay back in 2004, you could get a mount (not working, as is) for $300. to $700. I wouldn't sell mine with DDII roboscope tuned for less than $4K. -- It simply can't be replaced at any price and I like it much more than the $3K I just got for my 18 year old Questar 3.5. Hope that answers your question. Cheers.

#7 Michael Miles

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Posted 09 January 2009 - 04:25 PM

Hi Charles:

It's an impressive looking unit. However, I'm a machinist, so I wouldn't pay that much for something I could build for a fraction of the price. Still, if I charged for my time, I'm not sure I could do it for $4K...

Michael

#8 CharlesStG

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Posted 09 January 2009 - 04:49 PM

Wish I had machining skills - building a very special scope and I have to source out some of the machining work. Probably right on your time charge and that doesn't include the R&D which went into the design which I have to believe was pretty substantial because it works so well - the fitment of the parts really doesn't show in the photos, but there's some pretty impressive jointery and integration and choice of bearings to make this the most stable mount I've ever used. Wish everyone had one like this - there would be no more complaints on reliability, tracking and stability issues seen on so many commercial mounts. There's really about nothing to go wrong on a mount like this -- it's beautifully simple that way.

#9 PeterKA

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Posted 25 July 2009 - 10:04 PM

I found this thread while searching online for details on the Meade TeraBeam telescopes. The mounts are the main point of interest.
You describe using the mount for astronomy. I'd like to know more; as I had deduced from other web sources (see below) that it was a much more specialized mount: designed for use on buildings that sway back & forth - just a tiny bit, but the laser needed to be kept precisely on target.
If you have any scanned manuals or information, or other photos, I'd be very interested in seeing them.
Thanks, Peter Abrahams
http://home.europa.c...pe/binotele.htm
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Buildings tend to move back and forth in a sinusoidal path. The designers corrected this problem by altering the telescope gimbal and making some other changes in the telescope to insulate it from vibration. Sept. 2001
http://www.photonics...ArticleID=10264
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The Included gearboxes are manufactured by Harmonic Drive.
Here's how it works: The teeth on the non-rigid Flexspline and the rigid Circular Spline are in continuous engagement. Since the Flexspline has two teeth fewer than the Circular Spline, one revolution of the input causes relative motion between the Flexspline and the Circular Spline equal to two teeth. With the Circular Spline rotationally fixed, the Flexspline rotates in the opposite direction to the input at a reduction ratio equal to one-half the number of teeth on the Flexspline.
http://www.geocities..._telescope.html

#10 TimD

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Posted 31 August 2009 - 02:19 AM

Certainly solid looking mounts

#11 moynihan

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Posted 31 August 2009 - 10:33 PM

Very interesting, had never scene that mounting system before. I was curious how they were thinking of mounting them (having one of the Wegat type white tube OTA's myself)
Thanks

#12 CharlesStG

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Posted 08 October 2009 - 08:06 AM

Well, after asking the question more than 9 months ago on this thread, I must assume that no-one came across this thread who succeeded in making the Meade/Terabeam scope/mount combination work as my two units work. Mine use the Dob-Driver II pendant controller to run the drive motors and track the heavens with wonderful accuracy and stability.
Once again, this is the most stable portable mount I've ever used - simply no focus shake, so no damping worries -- puts my old A-P 400 mount to shame.

I rather thought I might be the only one to have made this combination work because of the difficulty. First, I was lucky enough to get Jim Wegat's fully useable OTA with his custom machined back-plate -- ready to go (most people bought a messed-up OTA version with an epoxied mirror and no back-plate, scratched tube, etc). Then, I had to find a 2" diagonal which would fit both Jim's threading AND short enough to clear the bottom of this rather short mount. Not many would work, but I found a Russian diagonal which works perfectly. Then, perhaps most difficult was to get something to drive the stepper motors and track the stars. I happened to have a Dob Driver II pendant controller from another project and I played with it ALOT until I got it to work right. Testing the wiring by mostly trial and error with 16 wires takes a bit of time. Finally, I discovered that I could make the motors run not just quietly, but absolutely silent by running the Dob Driver II at 9V instead of 12V using a cheap variable voltage car lighter plug found at Walmart. At 12VDC, the motors worked fine but with a bit of a high pitched oscillating whine. At 9V, this totally goes away.

Kind of nice to have something so unique which works so well, but I'd honestly prefer to have a few friends with this same set-up to share the enjoyment.

To put this scope in perspective, I should say first it's the mount which is truly exceptional and the telescope is merely excellent. As a combination of scope and mount, I MUCH preferred it (even with its higher weight and bigger case for transport) to my exceptionally fine Questar 3.5 which I sold last year as it wasn't being used any longer.
The images in the Meade were obviously much brighter than the Questar as expected for a 5" scope and the sharpness and contrast were good enough that I preferred the Meade overall. And while the integrated mount on the Questar is very nicely done, the stability is merely average whereas the stability on this Meade mount is quite amazingly solid -- "like a rock" isn't much of an exaggeration. Stability means ALOT to me as I find focus shake and image wobble from touching the eyepiece or wind to be unnecessarily annoying. Add to this stability the ability to use 2" eyepieces, enough light to use a binoviewer and enough motor torque to hardly care about balancing the eyepiece load, and finally a look to the unit which is pretty much Star Wars "cool" and it was no contest. The Questar is a prettier jewel, but somehow not quite a cool -- to me, anyway. Cool is as cool does and this Meade does it for me.

A couple of good machinist gents have commented that they think they could make something like this mount for less than $4000., and it might look like this mount, but I must doubt it would be as solid and functionally perfect as this set-up.

Really DO wish there were more who succeeded with these mounts as they are definitely worth the effort and expense. I think there are at least 40 of these mounts out there and many more of the Terabeam OTAs. :rainbow:

#13 TimD

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Posted 14 December 2009 - 06:38 PM

I do love big machined chunks of metal!

#14 will w

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Posted 14 December 2009 - 09:24 PM

charles, that tower below your name. is that your observatory?? you have one of a kind scope and mount. clr skys

#15 CharlesStG

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Posted 01 March 2010 - 07:23 PM

Yes, sorry for the delay -- I haven't checked this thread in some time!

Wile E. Coyote School of Telescope Making


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ROADRUNNER BLIND - "hehehehe!"

#16 greedyshark

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Posted 13 March 2010 - 06:42 PM

One just sold today on Ebay with the "buy it now" option...

http://cgi.ebay.com/...#ht_1880wt_1167

CS,
Charles

#17 Nighthawke

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Posted 13 March 2010 - 08:21 PM

I look at spiral ladders and think I'm gonna get stuck halfway up it.

#18 binkt

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Posted 14 April 2010 - 09:16 AM

Wow, okay... I've been trying to get "verified" on the forum for what seems like months now just so that I can respond to this thread!

I've got several of these setups and would some day like to get them working by constructing a controller for these mounts. It is so nice to see someone else with this unique equipment. Since I can't seem to find any compatible backing plates for the OTAs, I'm setting off to machine some.

anyway, great forum here guys. I'm happy to finally be a part of it!

#19 astronomerroyal

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Posted 16 May 2011 - 01:27 PM

I have the mount (but not the scope) and use it primarily for time-lapse motion control.

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As you can see, I removed (unbolted) a vertical support as well as the tube cradle. I also changed the power resistors so I could run the (bipolar) stepper motors comfortably at 12v. The controller is a microntroller-based DIY effort. It has been a real privilege to possess such a mount.

#20 CharlesStG

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Posted 25 June 2013 - 06:38 AM

Very cool use for your Terabeam mount! I agree completely with your statement that it is a privilege to be able to use such a mount. Strangely, due to an extraordinary life change, I now have my Meade/Terabeam scope/mount/controller for sale here and on ebay. Someone is going to be a happy camper. Charles

#21 Geo.

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Posted 25 June 2013 - 02:13 PM

I think Terrabeam folded when the guberment sold all that wireless spectum. I have one I picked up for $32, but the drive systen is EXT125. May have been an effort to get the price down.

The worm gears look like Meade LX units. Meade made these in 180 and 360 tooth varieties. The PICGoto++ should drive this pretty well,

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#22 Hitech

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Posted 25 June 2013 - 02:52 PM

Charles - I gather that's your scope setup you have posted on eBay? The seller is named Charles and is from Kansas. I thought you'd be hanging on to it despite your move to a new location.






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