From: "Jim Miller" 
To: "Orion105" ,
        
Reply-To: "Jim Miller" 


In spiders that I'm familiar with the "vane" are not responsible
to restrain twisting since other vanes are resisting movement through
tension that would otherwise be twisting the vane you are considering. You
can use wires rather than vanes which are tensioned to provide the support.
An offset four wire pair spider will offer the best support available.

jtm

----- Original Message -----
From: "Orion105" 
To: 
Sent: Thursday, February 20, 2003 4:15 AM Subject: ATM Spider design rules of thumb



Are there any rules of thumb regarding the length to width ratio of spider
vanes.  I see them made quite thin (10:1 or higher) and quite thick (4:1 or
so).  I guess you need width to stop rotation of the diagonal, but how much
is optimum?

I have seen spider vanes that taper in width markedly from the outside of
the UTA to the hub.  I have even seen a design that goes the other way.  Is
there any advantage in tapering?  It seems to me that resistance to
twisting is proportional to the width of the vane and so a tapered vane
would be only as good as its narrowest point.  Is this right?

Ado

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