Sorry,  but I somehow lost his original mail.   He just needed more
clarity on my special rubber bottom truss pole connections.


From wpk@saao.ac.zaSat Jul 18 16:21:03 1998
Date: Fri, 12 Sep 1997 09:38:01 +0200 (GMT+0200)
From: Willie Koorts <wpk@saao.ac.za>
To: Paul Shankland <pshankla@jiatfe.org>
Cc: pshankland@flakeysol.com
Subject: Re: Truss pole connections on your 9"


Hi Paul

Thanks for the nice words on my telescope and website.

Your mail prompted me to do something which I have been meaning to do for a
long time now, but just never got around doing it, ie. to add a drawing of
the bottom truss mounting arrangement to my telescope page.  Please have a
look at   http://www.saao.ac.za/~wpk/scope/rbox.html   and see if it is 
clear enough to see how the overcenter mechanism was made. 

As far as your other questions go, in hindsight, I was probably luckey to
have found the right size rubber after I already bought the Al. tubes for the
trusses.  I would reccomend going to rubber suppliers first (in Cape Town we
have two that sell rubber in almost any shape and size) to see what sizes are
avaliable and then select the truss tube (ID) size to match the rubber. 
BTW, I got my rubber from Cape Town Rubber Co. but that probably won't 
help you at all.

I am very happy with this design and found no movement (flexure) because of
the rubbers when using the telescope.  As the rubber age one might find it
breaking up (perish) which might become a problem.  One might try silicon
rubber instead, but since it is less firm than normal rubber, flexture might
be a problem.  Just for good measure, I cut a very coarse "thread" on the
inside of the tubes for the rubbers to expand into, but it is probably not
necessary. 

Shout if you need any more info.

Regards
Willie

ps.  Where did you get to hear of my site?  The ATM mailing list?  
     I noticed that I had a sudden flurry of hits lately.


                       Mr. W.P. Koorts ( wpk@saao.ac.za )    
                     South African Astronomical Observatory 
                   PO Box 9   Observatory  7935  South Africa
                 Tel. (27) (21) 47 0025  Fax. (27) (21) 47 3639
               World   Wide   Web  ( Work ) http://www.saao.ac.za
             World Wide Web ( Personal ) http://www.saao.ac.za/~wpk/