[ATM] Re: Second Thoughts on Mirror Support

[gjnelson at absamail.co.za (gjnelson@absamail.co.za)]

> The original John Dobson style scopes use carpet, not wiffle trees 
to
> support the mirror.  Thus it does appear to work to some (as yet
> unquantified) degree.  Think of  it as a 10000 point variable force
> cell.


This is a compliant support. Where you have the most force you have 
the most give thereby increasing the area of support and reducing the 
point forces. This would give you instead of three points of contact 
three areas of contact that would essentially merge not each other 
seamlessly dependent on how flat the support of the carpet is.

I guess it could be modelled in PLOP but setting it up or even an 
approximation of it would be quite a challenge.

Now what would happen if you RTV'd the mirror to the carpet? No sling 
would be required and you will still have a large support area. 

Geoff