ATM A newbie's first success

[Fred Floberg <atm@cyphyn.nai.net>]

Hi all,

I just wanted to introduce myself and tell you all of my success.

My name is Fred and I live in light polluted Wallingford Connecticut.
I've been reading this list for a little less than a month via Mel's
web page (Thanks Mel) and have been absorbing (or trying to) all of
the great info that you've been sharing with each other. Your conversations
have been a great help to me.

I had been toying with the idea of building my own telescope for the past
several years, mostly hindered by money. Recently a friend of a friend
mentioned that he had an 8" primary mirror and secondary that he'd bought
but wasn't doing anything with it. It had been lying around for so long
that he couldn't remember the focal length or even where he got it.

Anyway, he loaned the set to me and I set out to build a telescope around it.
I first measured the focal length and found that it was an f/6. Using
a sheet of plywood that was lying around the house I build a square tube
for it. The altitude bearings are just 4" PVC floor flanges used as toilet
drain connectors. They ride on thin strips of what I believe is delrin -
go to the super market and find one of those plastic cutting boards - that's
the material.

The mount is a standard Dobsonain type, except because of weight distribution
of the OTA the trunion cradle is much taller than a standard Dob (about 3'
tall). This isn't very satisfactory, as you might imagine, but it will do
for now until I can make an OTA with the balance point nearer to the
primary mirror.

The scope uses a sliding focuser, which isn't finished yet, and is rather
clumsy at this point.

I've learned a lot from building this scope. I can see the changes that
are needed to make it perform better, and why. That was the point of building
it; to get a better idea of the concepts involved in engineering a scope that
performs well. It's sort of a "learning lab" so to speak.

I've been using/testing this scope for the past week or so as I've been
working on it, and I just got in from the back yard tonight after having
viewed, for the first time in my life, M13, the globular cluster in Hercules!
Prior to viewing M13, I had only viewed the moon and Jupiter through a
telescope.

I'm so thrilled that words fail me! Something that I put together in my spare
time, and for virtually $0.00 (I'm actually using a jewler's loupe in lew
of a real eyepiece :-)), has enabled me to view celestial objects
that no other (commercial) telescope I've ever owned has allowed me to see!

I'm very definitely hooked on making my own telescopes! I may even get up
the nerve to grind my own mirror one day :-)

By the way, I'm using the standard ebony star formica - teflon block type
of bearing for azimuth. I find that the PVC on delrin bearing has a _much_
smoother feel to it than formica on teflon. Could this have to do with the fact
that there is more weight on the azimuth bearing surface than on the altitude
bearing? I find the PVC/delrin to be much more satisfactory with respect to
the general feel and ease of motion. Has anyone else here ever tried PVC on
delrin as a bearing surface? And can PVC be purchased in sheets?

Fred
--

F.C. Floberg - N1GVA
Latitude 41.4498
Longitude -72.8194