Bob
):-{])) <---- madden@netcom.com madden@svpal.org Remember amateur astronomers: "keep looking for the next Universe"
On Mon, 17 Apr 1995, Mark VandeWettering wrote:
>
> 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
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