New scope.

"Etok" wrote in message
...
My new scope is an old scope--a mid 90's Sky Designs dob, 18".
It doesn't weigh much more than my Tak 102 and G-11 mount combined (and of
course, the truck I used to transport them).
It's travel worn, to say the least. The fellow who owned it did what one
is
supposed to do with a big dob.
He went where the sky is dark. Lots of times. Lots and lots of times. So
the loading and unloading and
general wear and tear make it a little creaky and a bit wiggly in the
collimation department.
The old scopes use an aluminum ring running in teflon bearings for az.
The
teflon loads up with aluminum in a few minutes, and it gets kinda sticky.
The mirror box whacks the az encoder. And so on. But the price was
modest..
In fact all the scope's problems are fixable with a few trips to the
hardware store, a couple of astromart deals a few hundred bucks and a
pound
or two of Peet's coffee. The optics appear good at this poing. I'm going
to
test the mirror on Friday, I think, so we'll see. Anyway, it's good
treatment for a bad case of aperture fever.

One thing is for sure. You look at mars with this and it burns a hole
through the back of your head. But I find I can work around that by
wearing
light welder's goggles. Looking at M57, you only need RayBans.

I had the 18" f/4.5 mirror tested last night, first with ronchi and second
with foucalt knife edge.
90% zone was .0056 error
80% zone was .0056 error
70% zone was .0331 error
50% zone was .0310 error.

Looks like a 1/10th wave or better. I want to run the test again after the
mirror has been completely stabilized thermally and see what the difference
is. I don't think I'm going to have to refigure this one.
Heh.

Now I need to spend some time on the mirror cell and scope structure.
Sometimes you just luck out.

Regards,
Etok



__________________________________________________ ____________________
Posted Via Uncensored-News.Com - Still Only $9.95 - http://www.uncensored-news.com
The Worlds Uncensored News Source

Etok wrote:
The old scopes use an aluminum ring running in teflon bearings for az. The
teflon loads up with aluminum in a few minutes, and it gets kinda sticky.
The mirror box whacks the az encoder. And so on. But the price was modest..
In fact all the scope's problems are fixable with a few trips to the
hardware store, a couple of astromart deals a few hundred bucks and a pound

Do what I'm doing (or will be when it arrives) with my "new" SkyDesigns
14.5" - Get an AstroSystems TeleKit to house the optics.

--

-- Len Philpot --
-- http://philpot.org/ --
-- (alternate email) --