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Posts Made By: Walter Hamler

October 5, 2003 08:39 PM Forum: CCD Imaging and Processing/Solar System

Re: Saturn: 12.5" f/6 Cave

Posted By Walter Hamler
Tom Cave would be proud of you!! Great image.

Walter

October 20, 2003 08:21 PM Forum: Equipment Talk

Cassegrain Question for Rick and Vlad

Posted By Walter Hamler
Guys (Guru's!!)
The local university has an astronomy club. One of the members has found the remnants of an old Tinsley 12" cas.
It is missing the secondary. What do they need to know in order to determine the size, radius, figure of a secondary before one can be made? I suggested to first determine the fl and figure (sphere, paraboloid, other?) of the primary and then the length of the tube (they have the origional). That should give them some starting info.
Also, will a flat be necessary to figure or can a foucault and or star test be done allowing a setup to hold everything in position?

Walter

October 29, 2003 08:13 PM Forum: CCD Imaging and Processing/Solar System

Sun just now

Posted By Walter Hamler
It cleared up here in Central FL so I grabbed another few shots. I think the focus is better on this one. 4" refractor and Coolpix 4000.

Walt

November 26, 2003 11:12 PM Forum: Equipment Talk

Saddle Plates and Mounting Plates

Posted By Walter Hamler
I have an older GEM that I need to replace the ring mounting system with a better design. Am thinking of the Williams Optics Dovetail and Saddle Plate combo. Has anyone out there seen this version, and does it use the "standard" Losmandy plates?

Walt

December 3, 2003 02:23 AM Forum: Equipment Talk

Mounting Encoders for Digital Setting Circles

Posted By Walter Hamler
I am tweaking a GEM and want to add dsc's. I have decided that I want them geared to the dec and ra shaft. Are there any guidelines out there for gear ratios or is that something you tell the setup program when you first fire up the computer or controller?

Walter

December 6, 2003 01:35 AM Forum: Telescope Making

Painting over Polyurethane

Posted By Walter Hamler
I am redoing the tube for my 10" f/6 dob with a new sonotube. I have coated it with numerous coats of polyurethane to seal it, but want to paint with a durable paint. In the past I have had a terrible time getting paints, especially latex, to adhere properly to the poly, even after sanding completely. Any suggestions from the paint pros out there. I do not have access to a spray painter so I need suggestions for brush and/or spray cans.

Walt

January 1, 2004 02:50 PM Forum: Telescope Making

Made some Modifications

Posted By Walter Hamler
I have had a TAL-2M gem for a few years and have been unhappy with the drive motor since it is a 12vac synchro motor with not much torque. Other than that it is a very robust mount that can easily handle 30 pound loads. I recently acquired the complete drive system from a Celestron CI700 that the owner had replaced with a goto option. I hoped that adapting it to my mount would be fairly easy as both mounts utilizes a 180 tooth worm wheel.
I finished the project yesterday and here are the results.
For those familiar with the TAl-2 it uses a tangent arm for the declination axis. I had to modify that to use ball bearings and a 1/4x20 lead screw so that the motor would be able to work properly.
I haven't had clear skies yet but so far it seems real smooth and the availability of pec, dec backlash adjustment, and an abundance of drive speeds and correction rates is a BIG plus!!

Walter

January 1, 2004 02:54 PM Forum: Telescope Making

Made some modifications 2

Posted By Walter Hamler
Another pic of the RA motor installed. It is really clean as compared to the Russian motor. The gear was easily obtained from SDI and I was even able to use the origional motor bracket.

January 1, 2004 02:59 PM Forum: Telescope Making

Mods 3

Posted By Walter Hamler
This is the Dec motor. The origional tangent arm used a big knob on a spring loaded lead screw. The spring pressure was pretty high and the motor wouldn't turn it properly. I changed it to a 1/4-20 threaded rod running in ball bearings. MUCH smoother. The gearing works out to give a basic dec rate of 2.5 arc sec/sec at the lowest rate speed of .3 siderial. I think that will be plenty fine enough for smooth dec corrections but when you bump the rate up to 16x that puppy flies!

Walt

January 2, 2004 10:26 PM Forum: Equipment Talk

Refractor Collimation

Posted By Walter Hamler
I spent some time collimating my 4" refractor today with our club's new collimator. Basically I was squaring up the focuser and I first did so without the 2" diagonal. Then I put the diagonal in and re-tested. It is off about 1/2". No way to tweak the diagonal and it stayed the same no matter which way I turned everything. So, me thinks, since I always use the diagonal, I will square it up with the diagonal in place. Did so, but now I am wondering, "is that really the best alternative?"
What say the experts out in Astromart Forums Land?
(I've still got the laser and time on my hands! HA!)

Walt

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