Hi Folks,
I started a thread over in sci.astro.amateur about an idea I had for a
tracking platform for Dobs:
http://groups.google.com/group/sci.a...d7cb66/?hl=en#
And then another thread in the Yahoo Eqplatforms group:
http://tech.groups.yahoo.com/group/eqplatforms/
(I think you'd need to be a Yahoo member to read these ones.)
I put my (evolving) thoughts (including Lego mockups!) on a page at:
http://cluton.googlepages.com/equatorialcradle
Going by some of the discussion in the Yahoo group, it seems like the idea may have some uses. It wouldn't be as compact as I was hoping, but one might be useful as a permanent structure (eg. in the backyard).
In summary, it uses 2 ball joints to form an axis - but variations
could use spherical bearings, plain bearings or even a shaft through a
block. It eliminates the roller-arc of the existing platforms I've seen
(which I think would make it much easier to fabricate). I suspect it would be smoother too.
Cheers,
Chris.