Anyone Else Running This Complete Meade/Terabeam?
Posted 04 January 2009 - 01:00 PM
Posted 06 January 2009 - 04:00 AM
Posted 06 January 2009 - 08:55 AM
Posted 09 January 2009 - 03:50 PM
Posted 09 January 2009 - 04:25 PM
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...
Posted 09 January 2009 - 04:49 PM
Posted 25 July 2009 - 10:04 PM
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
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
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.
Posted 31 August 2009 - 10:33 PM
Posted 08 October 2009 - 08:06 AM
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.
Posted 14 December 2009 - 09:24 PM
Posted 01 March 2010 - 07:23 PM
Wile E. Coyote School of Telescope Making
ACME mailorder kit in a box -- (karolus rascalius) :dabomb:
ROADRUNNER BLIND - "hehehehe!"
Posted 13 March 2010 - 08:21 PM
Posted 14 April 2010 - 09:16 AM
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!
Posted 16 May 2011 - 01:27 PM
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.
Posted 25 June 2013 - 06:38 AM
Posted 25 June 2013 - 02:13 PM
The worm gears look like Meade LX units. Meade made these in 180 and 360 tooth varieties. The PICGoto++ should drive this pretty well,
Posted 25 June 2013 - 02:52 PM