RE: ATM Dob vs Equatorial bearing sizes

["Bertapelle, Ken" <Bertapelle.Ken@tci.com>]

Actually they're even bigger than that.  On my 10" dob, which I made
by following the design in Kriege's book, the diameter is close to 
18".  I've forgotten the exact line of reasoning, but the basic point
is that the large diameter allows better low friction performance, and
also simplifies balancing the scope.

- KenB

> -----Original Message-----
> From: lifedata@vol.com [mailto:lifedata@vol.com]
> Sent: Wednesday, June 16, 1999 11:24 AM
> To: atm@shore.net
> Subject: ATM Dob vs Equatorial bearing sizes
> 
> 
> 
> I see equatorial bearings of fairly small size, but Dob bearings get
> up to 10 or 12 inches.  Why the huge size?
> 
> Jim L
> 1 John 5:13
>