Re: Mirror cells

resource@rahul.net
Tue, 18 Apr 1995 21:45:35 -0700 (PDT)

I agree with Dean. I put three garden hose washers on the cell, sunk into silicon, then set the mirror onto those. I have not found any movement in my primary. Of course, using Berry's design (although I modified it), I did put three support posts to hold the mirror in too. They also use silicon to secure them to the mirror. I have columnated once in the two months I've been transporting and using the scope since its completion. I would not like to have any metal in contact with the mirror.

Even when I had a Novak cell on my olf scope, I put some felt cushion between the retaining clips and mirror. No metal, please.

Mark

On Tue, 18 Apr 1995, Dean Ketelsen wrote:

> I like the idea of a set of "hard points" to define the axial
> position of a mirror, but don't like the idea of having a metal
> point contact on the back of the mirror. Any sharp impulse
> could transmit directly through the bearing and possibly damage
> the back of the mirror. Is there a chance of using nylon or
> delrin balls? One guy's opinion...
> -Dean
>