Re: ATM Ball-and-Socket flotation for mirror cell

["Jim Dolson" <jdolson@iserv.net>]

My 6" dob has a somewhat similar joint which works quite well.  It is a
knuckle-joint and is based upon the one that Mr. Cox described in an article
in the old ATM magazine on mirror cells.  The only difference is that mine
was done in wood.

 Jim

----- Original Message -----
From: "Edwin Spector" <ems@lucent.com>
To: <atm@shore.net>
Sent: Thursday, March 15, 2001 9:31 AM
Subject: Re: ATM Ball-and-Socket flotation for mirror cell


>
> From: don clement <donald_clement@yahoo.com>
> <<
> An alternative to using Teflon ball and socket could
> be to use a solid machined compliant (flexural pivot)
> universal joint. The compliant universal joint would
> be simple to make: mill a solid shaft such that there
> are two thin rectangular sections at right angles to
> each other. [...] >>
>
> I used a simpler system - a single nylon screw. It allows a few degrees of
> flexing, but is stiff enough not to shear. Screw is 6mm (1/4 in).
>
>        |nut|
> ---------------------
> ////////| |//////////  plywood (supporting mirror)
> ---------------------
>        |nut|
>         | |  exposed bit of screw
>        |nut|
> ---------------------
> ////////| |/////////  plywood (fixed)
> ---------------------
>
> Edwin
> Bath, UK.
>