ATM Misc. Ramblings

[Adrian Pederson <PEDERSON@uwplatt.edu>]

    After being out of town for the past week I'm now back and ready to fine
grind my 8" mirror. After quickly wearing down my solid glass disk, it was
about 1/4" thick and began chiping at the edges, I'm back to my quickly wearing
tiles. Hopefully I can finish fine grinding before I wear through these:)
Anyway at least I'm over my initial frustration with the whole process.

    I am also currently working on some of the mechanical portions such as the
mirror cell and a two-axis positioning table for the Foucault tester. My cell
design is a 9-point support system, but I have several questions. First, what
type of material is best for the triangular support plates, and how do I make
the pivots below the plates in order to keep them from moving laterially when
the mirror is tilted? In other words, how do I lock it in place while still
allowing it to pivot? Can these plates be glued to the mirror or should there
be low friction support points? For the collomation adjustment screws I see
most designs have a push-pull setup, but I was wondering if this is really
nessesary, I was thinking of having a set of T-nuts in the middle of a plywood
sandwich, with a little thread-lock to keep it in place, this should allow for
adjustment with only 3 bolts. Anyone out there try this yet? Comments?

    I have also been wondering about plywood for the tube. There has been
mention of birch and furniture grade plywood. What types are readly available
and don't cost too much?

    Enough for now, time to get back to grinding.

                                                Adrian Pederson
                                                pederson@uwplatt.edu