Question

Ok, I was thinking today ( that's BAD! ) as I cleaned my Stargazer Steve
dob.

Could a mirror cell be made that mostly would be a single layer of something
like plywood that would fit inside a sono tube, instead of having all the
adjustments, dry fit the cell in and mark the tube where the cell disk would
be totaly flat and 90 degrees. Pull it out and make a cardboard ring with
wax paper covering that would fit the outside of a mirror. Afix the ring to
the disk and fill it with RTV a nice level layer and then place the mirror
in the ring and let it cure for a few days. They you could either remove the
ring or just leave it on. Then place the mirror on cell into the tube to the
marks and fasten it in somehow.

Then use a spider ( not black widow!) and using a sight tube in the eyepiece
holder work the secondary mirror and spider until it was in total alinement
and then tighten it up checking to make sure you didn't mess it up doing
that.

This would then make for a scope that wouldn't need re-alineing all the
time.

I've not drawn this out, but for small scopes, say up to a 6inch mirror,
whould this work?

Now I'll go hide! ;{

Starlord wrote:
Ok, I was thinking today ( that's BAD! ) as I cleaned my Stargazer
Steve
dob.

Could a mirror cell be made that mostly would be a single layer of
something
like plywood that would fit inside a sono tube, instead of having all
the
adjustments, dry fit the cell in and mark the tube where the cell
disk would
be totaly flat and 90 degrees. Pull it out and make a cardboard ring
with
wax paper covering that would fit the outside of a mirror. Afix the
ring to
the disk and fill it with RTV a nice level layer and then place the
mirror
in the ring and let it cure for a few days. They you could either
remove the
ring or just leave it on. Then place the mirror on cell into the tube
to the
marks and fasten it in somehow.

Then use a spider ( not black widow!) and using a sight tube in the
eyepiece
holder work the secondary mirror and spider until it was in total
alinement
and then tighten it up checking to make sure you didn't mess it up
doing
that.

This would then make for a scope that wouldn't need re-alineing all
the
time.

I've not drawn this out, but for small scopes, say up to a 6inch
mirror,
whould this work?

Now I'll go hide! ;{


Theoretically: yes.
In reality: no.
The time you would save in not adjusting the primary you would loose in
centering the spider. The difference in time it takes to fabricate a
flotation cell without adjustment as opposed to with is negligible and
if its made properly it can stay in collimation for months under normal
use. the spider will not stay in collimation any longer.

Ian Anderson
www.customopticalsystems.com

It was just a "Shot in the Dark", what with the cold dry mojave winds
blowing outside, I was was just thinking and as I said, that at times can be
bad. ;

wrote in message
oups.com...


Theoretically: yes.
In reality: no.
The time you would save in not adjusting the primary you would loose in
centering the spider. The difference in time it takes to fabricate a
flotation cell without adjustment as opposed to with is negligible and
if its made properly it can stay in collimation for months under normal
use. the spider will not stay in collimation any longer.

Ian Anderson
www.customopticalsystems.com

The adjustments are really needed to get the primary mirror to point exactly
up the tube to the secondary and then to the center of the EP.
I put 3 blocks in my telescope tubes and bolt the mirror cell to those with
the holding bolts pointing up the tube. The blocks are glued and bolted to
the side of the tube so that they won't move. The blocks aren't quite at
120 degrees from each other so that the cell will only go in one way. This
allows me to remove the primary and replace it without losing the alignment.
The rest of making a telsecope so that it doesn't need frequent alignment is
to make everything good and solid so that the varous parts dosn't move about
when transporting

--
Why isn't there an Ozone Hole at the NORTH Pole?