SV: ATM 6" Dob: How Easy? How Cheap? How Heavy?

["Nils Olof Carlin" <nilsolof.carlin@swipnet.se>]

Brent wrote:

> For a 6" mirror in an 8" x 48" tube, is all that 3/4" plywood really 
> necessary? I checked Home Depot last week and a 4' by 8' sheet of 
> 3/4" birch ply cost 50 bucks and weighs more than my sofa. By my
> calculations, the sidewalk plans would use over 40 pounds of 
> plywood and that sort of argues against the convenience of a small 
> Dob for spur of the moment backyard observing. Surely something made 
> out of 1/2" or 5/8" ply, maybe with a 3/4" ground board would be 
> sturdy enough. What would be a target weight for a sturdy rocker box 
> for a 6" f/8 'scope, 25-30 pounds?

The total weight of my 6" (f/6) spur of the moment scope is 25 pounds -
including the battery-powered equatorial platform! (square tube from
1/8" ply, finder included, =11 lbs, rocker 5/8" ply =8 lbs, eq platform
=6 lbs, including 2 lbs of batteries).

The lighter the tube, the lighter rocker box needed, and the lighter
ground board, and the better damping of vibrations. The original Dob
design as on that web page just isn't optimized for weight.

 Maybe we ought to collect our common ideas on very light *small* Dobs?
I think they can be awfully handy and nice.

Nils Olof