Re: [ATM] Some advice on 18pt cell design

["Olivier Biot" <olivier.biot@versateladsl.be>]

From: Mel Bartels

>> The triangles on my 18 point cell are equilateral. The support points are 
>> not. Why should they be? No one says that the support points have to be 
>> at the vertices of the triangles.
>>
>> Any triangle will balance naturally if supported at its centroid, no 
>> matter how skinny or malformed it is. Right?
>
> It may balance, but the relative forces on each support point will not be 
> the same - disasterous!

I agree.

However, the error I "introduce" in my design is .6mm (1/40 inch) and as I 
am not using a point-like support but some "pad" (with a finite contact 
surface of approx. 3cm2) instead, I *guess* it's safe to use equilateral 
triangles for supporting the 18 points cell :)

Of course, I realize the 18 points cell is overkill for this mirror, but I 
like its design, and I am still playing with the idea of building an astatic 
support for it, similar to what Frederic Gea presents on his website.

I however still need to discuss some (mainly machining) aspects with someone 
who lives in my neighborhood (Antwerp, Belgium) whom I still need to find, 
as I have no machine shop :)

Best regards,

Olivier 


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