Re: ATM 2001 Oregon Star Party telescope walkabout

["Jim Miller" <jim@jtmiller.com>]

Mel
Some questions below:
tnx
jtm

----- Original Message -----
From: "Mel Bartels" <mbartels@efn.org>
Cc: <atm@shore.net>
Sent: Thursday, August 30, 2001 4:21 PM
Subject: Re: ATM 2001 Oregon Star Party telescope walkabout



Flex rockers have 3 characteristics:

        1. the 4 altitude support points each sit directly above the 4 (not
        3) azimuth support points

        2. the rocker is made from thin plywood or metal tubing such that
you can
        easily flex it with your hands, ie, Greg Babcock's is only 1/2 inch
thick
        or so and made from a single sheet of plywood

I assume "flex" was not a design objective but a result of an optimization
for light weight without reducing effectiveness?  Doesn't the flexibility
cause an error in ALT tracking and guiding or is the flexibility in another
axis?  By rocker do you mean the nearly semicircular part of the ALT
assembly?  I'm interested since I'd like to reduce my ALT rocker (if same
terminology) mass.  (see scope at www.jtmiller.com)  I'd assumed that any
ALT errors were a no-no.

        3. the altitude rim extends down past the outside of the flex
rocker,
        almost touching the ground
Could you define altitude rim?  Do you mean the rim of the assembly
including the primary which in Greg's case drops inside the ground ring?

        Typically the ground board is a ring of wood or foam core or metal.
It
        needs to be rigid since the rocker is not.
I don't see how one compensates for the other.  I'm in the middle of a scope
design and could potentially take advantage of some of this

tnx
jtm