Building an Equatorial Mount
September 2009 :
This article will end up on the subject of a German equatorial telescope mount after I give you a little background.
It seems to the best of my memory that it started when I was 9 or 10 years and saw a go-cart for the first time. Naturally as a kid I had to have one, so I told my father and he said let’s build it! So this could let’s say be the beginning of it.
Since the sixties there have been numerous internal combustion projects, some good some not so good, but good or bad you retain the knowledge, experience, and hopefully the patience for the rest of your life. When I joined Skyscrapers I found out I had a long way to go to be patient. I found myself looking for stuff that I could not see! How do you find stuff if you cannot see it? Being a member now for four years my fine friends of Seagrave have taught me a whole lot.
I have seen a lot of fine instruments produced by our members and thought I might want to try my hand at a couple of projects. I had already built a tripod for my 35mm camera, then a half dozen or so telescope piers, then there was the bino mount.
The next project proved to need a little more accuracy, it was my black walnut tripod and its altazimuth mount which contained some close tolerances. I have been thinking about a GEM for a while, but there was much I did not know or understand—more patience.
If I remember correctly it was at the Womens’ Wilderness Weekend earlier this year that club member Jack Szelka said why don’t you just build a GEM? Not long after that I was buying materials and getting started. I did not have any plans to go by, nothing telling me what size to make anything, but I said I don’t think that should hold me back. I went on the Stellafane web site an copied a picture of Al Hall’s and Dick Parker’s mounts and said I will build something that resembles them but just smaller. Let me say there were many more trips back to that website for the mounds of information it provides.
Being smaller I had some aluminum tubing that measures 2.5 inches in diameter, that was to be the holders for my bearings and my 2 main shafts. Quite a bit of the measurements after that are all relative to those two sizes—something will look wrong if the sizes are not relative.
My main reason for doing this project was to have a mount that tracks and does not have to be manually moved to follow an object. I knew if it was accurate I would possibly be able to do some time exposures with it. After talking to Bob Horton about tracking he suggested a Byers Drive unit would fit my needs. I advertised on Astromart for one and couple of weeks later it was in my possession, but unfortunately it was geared wrong. With a few e-mails to Al Hall he had the unit tracking very well with a change to the gearing ratio.
I do believe if you come AstroAssembly I will have it there. What did I get out of building this? I now have more patience than when I started. What else did I learn? Probably nothing because I still look for stuff that I cannot see!
