Re: ATM bearing size - fork mounts

[Tom Coan <tcoan@teleport.com>]

Gary,
 2" steel shaft is what I have on my 10" F6, a 19" length to be 
exact. The length determined by one's latitude and the height the
scope needs to be suspended so the bottom of the tube clears the
mount or ground.
 Its more than sufficient. If I had it to do over again.. I'd still
use 2" shaft. It adds a considerable amount of weight which is good
and bad. Bad for moving of course but good for one very stable mount
with weight added right where you want it, down low. My mount minus
the tube assembly weighs about 90lbs. This is also because the forks
are also steel. The other advantage to this is its nearly indestructable.
If someone trips or falls on my scope its not the scope that will
get hurt.
 Cost was another advantage with steel. If the length of the steel pieces
are under 2 feet they sell it as scrap by the pound. I obtained all the
steel for my fork mount, shaft included, for about $20. Just go to a
local steel fabrication outfit like U.S. Steel and ask.
 Go to my home page below to see a picture of it and another brief
description.

At 04:13 PM 9/3/97 +1000, you wrote:
>Hi all,
>
>I am considering building a fork mount to hold a 12" f5 newt. I have some
>brand new 50mm self aligning pillow blocks. Would this size ra shaft in
>either steel or aluminium be sufficient? If not what are your
>experiences/opinions of what size would be sufficient?
>
>Gary
>
>
Tom Coan                                 steelheader/amateur astronomer
Product Engineer/Programmer Intel Corp.  email:tcoan@teleport.com
Hillsboro,OR,USA                         homepage:www.teleport.com/~tcoan
      if myself((TN *)make(telescope->nightsky.dark)) return HAPPY;