Re: [APML] Baffle tube grease

[Lorenzo Comolli <comolli@libero.it>]

Thank you Steve and all others for the useful comments, I've yet dismounted the
primary mirror and I found that 99% of grease was at the bottom of baffle tube,
so I redistribuited on the tube, but it was not sufficient. So I've
redistribuited only on the top part of the tube.
Then I've tested the scope and "discovered" that my 15' mirror shift (yes, half
a moon!) was really a lot smaller. So I thinked that if I put the grease all
over the tube, it will be even better.

About mirror flop you are right, grease is not sufficient, I've realized a
mirror block as described on Robert Reeves book (images on my website) that
resolved 90% of the problem. But now I've a crayford focuser and I'll modify the
tube to be completely lockdown. But when I unlock it I prefer not to have a huge
mirror shift!

Lorenzo


"Steve..." wrote:

> Lorenzo,
>
> Do as you wish but before you rip your SCT apart and grease it, try just
> "re-distributing" the current grease. This is done by simply turning the
> focuser continually until the mirror has moved all the way to the far end of
> the baffle tube and then reversing direction so as to move it all the way to
> the rear of the baffle tube. Do this 3 or 4 times.
>
> I have a 12" Meade SCT and once I learned how much better this made the
> movement of the primary, I started doing it every session out. It makes a
> very big difference with my OTA.
>
> I am not certain that any thing you do regarding grease will help mirror
> shift too much. It will make the focuser much smoother though. A mirror
> lockdown bolt is about the only way to solve that problem.
>
> My $0.02.
>
> Steve...



--
____________________________________________________________
Lorenzo Comolli
Internet: http://digilander.iol.it/comolli/
E-mail: mailto:comolli@libero.it

Socio del Gruppo Astronomico Tradatese
Internet: http://gwtradate.tread.it/tradate/gat/
____________________________________________________________



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