To: atm{at}shore.net
From: Andy Saulietis 
Reply-To: Andy Saulietis 


Re:
> > I'm planning a similar scope.  But the solution is pretty easy.  Have the
> > parts align using 3 balls fixed to one part drop into 3 radial V grooves
>in
> > the other part.  This is called a kinematic coupling, and you can get
> > *micron* level repeatability from it in metal.

Not quite...this would assume that the 3 grooves intersect the 3 balls
exactly. The true kinematic mount with 3 balls has a hollow cone for one
point, a radial v groove for the second, and a flat surface in ~ the plane
of the 3 balls for the third. The cone/ball constrains all 3 linear
directions, the groove/ball together with the cone/ball constrains 2 of the
3 rotational directions, and the flat surface constrains the 3rd rotational
direction.

In my earlier post today re collimating a folded refractor, I should have
added that after the mirrors are alined, the focuser must also be squared
to the resuling OA, one way would be to use a laser collimating tube
in the focuser, with a translucent center-marked screen in front of the
objective lens..just adjust the tilt of the focuser until the laser dot is
centered on the screen.




Andy Saulietis
ISS Enterprises
PO Box 19
Mayhill NM 88339


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