Re: ATM Wiring Spiders

["Edmund Stevens" <ed@flyingscopes.com>]

----- Original Message -----
From: "Mark Gray" <mark.gray2@btinternet.com>
To: <atm@shore.net>
Sent: Wednesday, February 13, 2002 6:57 PM
Subject: Re: ATM Wiring Spiders


>
> If the main point of using a wire spider is to minimise diffraction (and
> reduce weight),
> would the added complexity and vibration proneness of this type of spider
> not outweigh
> the pros, on a fast newtonian, as they are not generally optimised for
> planetary use anyway?
> That is would this type of spider design not be best suited on a long f.l.
> newtonian?
> As far as saving weight, is it worth saving 150g of total scope weight for
> reduced diffraction
> and a host of engineering problems? I just need convincing before I race
> down to the local
> music shop for some guitar strings!!! (Also i've just started making my
> spider from crate strapping. There seems to be a few supporters of this
> material)!

If you start the strings from an offset position on the diagonal holder you
will find that there is no vibration at all.  I get more vibration from
accidently bumping the scope and the upper cage vibrating.  The offset
design is extremely stable.  Mel has a page with pictures and text about the
offset design somewhere on his site.

Ed