Re: Mirror cells
Mark VandeWettering (markv@tick)
Mon, 17 Apr 1995 11:34:48 -0700
On Apr 17, 10:57am, Rik Hill wrote:
> Subject: Re: Mirror cells
> >
> > I'm planning a 10" f/6, and here are my current plans: The mirror is
> > held to the mirror support a la Berry; with silicon cement. This provides
> > a strong yet flexible hold, support from the edge as well as the bottom,
> > and I can use as many points of support on the bottom as I want.
> >
> > If anyone has opinions or experiences to relate, I'd love to hear them!
> >
> I have a 14" mirror mounted this way and find that every time I
> move the telescope I have to refocus to accomodate the different
> compression of the silicone support. This would be disasterous for
> any long exposure photography. -Rik
>-- End of excerpt from Rik Hill
A quick tip, offered to me by Bob Schalk at our workshop. When you glue a
mirror down like this, put a ball bearing in each of the pads of silicone.
This keeps the silicone from flexing under the weight of the mirror.
Works like a charm.
Mark