ATM 80/20

[Jeff Crilly <jeff@communities.com>]

At 11:38 AM 5/14/97 -0600, SWDuncan wrote:
...
>I was going to use sort of a truss tube design, only with one member. My
>company over-bought on some 80/20 aluminum extrusion that would make a good
>backbone - I could mount everything off of it, and then make a light shroud
>around it.
>
>This would also make it easier to experiment with baffles, etc. AND I don't
>have to hunt around for a tube of the right OD & wall thickness.
>
>The problem is that the 'stick' has a much lower moment of inertia (sort
of a a
>measure of stiffness) than a large, thin-walled tube. Since tubes are used
all
>the time that wouldn't be a problem, but with the bar, I wanted to check it
>out.
>
>

Fyi.. these 80/20 guys are at http://serv1.fwi.com/8020/

This 80/20 stuff looks great.  I'm thinking about building some
sort of 'yoke' equatorial mount for an 8" dob I have.  And I'm considering
building the whole thing out of aluminum and some bearings.
With this 80/20 stuff I could cut down on a lot of time cutting/drilling and
fitting.

Is this stuff expensive?  My guess is that its somewhat rigid.  Is it?

jeff