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Posts Made By: Walter Hamler

March 4, 2013 01:23 AM Forum: Equipment Talk

New Drive for an older Mount

Posted By Walter Hamler
I have a Byers 58 mount that had been converted to a stepper drive GOTO. Unfortunately the controller is toast and no support. I was wondering if anyone in this community has experience converting this or similar mounts to just a plain jane drive with basic sidereal rate and a plus/minus of enough to use for guiding?
I once adapted a Losmandy Digital Drive to a TAL Russian mount with great success. Are those drive readily available still?

Walt

June 22, 2013 10:03 PM Forum: Equipment Talk

Computing sidereal gear ratios

Posted By Walter Hamler
I just came into an old Cave Astrola GEM that is pretty old and beaten up, but once I took it apart it will clean up good.

The drive had been modified with a Pittman Servo motor, 24 v, about 1400:1 gear reduction according to the label. When I apply 12 vdc it turns at 1.3 rpm +\- a
second or two. The gearing on the motor is 46 tooth to a 144 tooth spur gear, attached to the worm shaft with a 100 tooth worm wheel.

Since the mount only came with an 8' f/8 ota and no electronics or controller, I have no idea what was driving the motor. Could someone explain the gear ratios
to me and tell me if they are close to being correct for a sidereal drive rate?

I thought I understood all that math at one time but it has since left the building!! :-)

Walt

October 3, 2013 11:42 PM Forum: Telescope Making

Cassegrain Assembly

Posted By Walter Hamler
Our club has received the gift of a 12.5" Cassegrain mirror set. I have determined that the primary is f/4 but don't know what the secondary magnification is. It is about 4 inches in diameter.
I have made quite a few newts and many I ground and polished the mirrors, but have no experience with Cassegrain optics.
What I would like to find out is how difficult it would be to assemble one and where would I get the proper parts like mirror cells and secondary holders for cass optics. I have looked at the obvious websites and none are listed that I could find.
Any hints would be greatly appreciated. Another thought is to simply sell the optics and purchase something else. Any thoughts on the possible value of the mirror set?

Walt

March 26, 2014 03:13 PM Forum: Refractors

Aftermarket focuser for Celestron 6" Refractor

Posted By Walter Hamler
What are some recommendations? I had a GSO on an Orion 120 that I wasn't happy with; too finicky to adjust. Does Moonlight make one for the C-6R?

Walt

March 26, 2014 03:13 PM Forum: Refractors

Aftermarket focuser for Celestron 6" Refractor

Posted By Walter Hamler
What are some recommendations? I had a GSO on an Orion 120 that I wasn't happy with; too finicky to adjust. Does Moonlight make one for the C-6R?

Walt

June 13, 2014 09:17 PM Forum: Solar System Observing

My best Saturn as a new imager

Posted By Walter Hamler
Shot this a few weeks ago but have been playing with Astrotrakker and Registrax. Shot through my C8 on a Byers mount.

Walt

June 23, 2014 07:08 PM Forum: Mounts

Remember these mounts from Richard Berry?

Posted By Walter Hamler
I recently acquired a 6" refractor and it may be a little too much for my Byers EQ Mount. So, I remember this mount from one of Berry's books. I had to buy another copy to get the compete plans but it went together fine and I just did first assembly and attached the OTA. Pretty smooth and very rigid if I do say so myself.

Walt

August 29, 2014 07:30 PM Forum: ASTRONOMY

Beta Scorpius A

Posted By Walter Hamler
I got two opportunities the past two nights to observe with my new ES 152 refractor. After observing Saturn successfully on both evenings I took a peek at Beta Scorpius A. According to Burnham it is a 0.5" separation. According to Wilipedia it is 3.6". Because of the magnitude difference it was hard to judge. I got definite separation at 130x but looked cleaner at 225. I looked at a couple of wider doubles like the Double Double. It was a clean split at around 60x.
I am having a hard time believing the 0.5" value but the 3.6" seems a little wide for what I saw.
Comments?

Walt

September 12, 2014 03:30 PM Forum: ASTRONOMY

Re: back to your roots

Posted By Walter Hamler
Well, I am almost 72 and started out with a small 3" newt that was advertised in S&T for 29.95. I got it for Christmas when I was 12 or 13. Great scope until I decided to polish the mirror with Brasso! Oh well, live and learn :-)

I got into atm when I was overseas in the Navy and most of my scopes since have been ones that I made mostly. Now I have three main scopes, a C8, and two 6" refractors. However, I have built many scopes for our club over the years just to stay with the atm hobby. Now I am finishing up a 12" f/5 truss tube dob that I will keep for me. It will likely be my last one to build, but I still enjoy taking them out to use as often as the weather will allow.

But, no, I don't want to go back to that 3" newt! :-)

Walt

September 14, 2014 12:50 AM Forum: Refractors

Re: 102 vs 102 ED

Posted By Walter Hamler
I'm not a guru but have owned several small refractors, all achromats, and have observed with many small and medium ed's. That said, I would venture to say that on most nights with average seeing, you would be hard pressed to really see much improvement from an ED or APO design over a good long focus achromat in the 80 to 102 range. When you get to the 120/127 and larger category the color defects of the achro will start to show enough that you can readily see the difference. Color aberration will be the first noticeable failing. The next will be softness at higher magnifications when the atmosphere allows those attempts. I can remember one night years ago when I was observing Saturn at approximately 300 x in my 127 f9 achromat. The image was actually very good, even confirmed by many others. Until a fellow club member put the club's Tech 140 on Saturn. Below 200 x there really wasn't much difference to be seen. As soon as the power went to over 350 the difference was very apparent. You really have to ask yourself how much time do you plan to observe at the high powers. If not much then be very happy with the nice scope you already have!

Walt

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