From: "Mel Bartels" 
To: 
Reply-To: "Mel Bartels" 


>>> Theory aside, if I wanted to build one of these beasts (a wire spider)
how much tension is usually used to create a good stable setup?

Very little with my wire spider.  In fact, the wires are only slightly
tightened from a limp state.

>>> How do you go about making sure that the diagonal holder is centered
(and properly offset)

I built a little jig that holds the diagonal hub in position while I string
the wire and tighten it up.  You can actually collimate the diagonal
permanently as you tighten the wires.

>>> Also, isn't there more room for vibration in such a setup over solid
vaned spiders?

Well, one might think, but I find my wire spider more stable than any
traditional spider where the vanes meet in the center.  It's extremely
resistant to vibration, extremely strong (I can easily move the scope
around by grabbing the spider), and cheap cheap cheap to build.

My wire spider is at
http://www.efn.org/~mbartels/tm/trilateral/trilateral.html

Mel Bartels

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