FYI. I came upon two interesting goniometer designs.

For the record, a goniometer is a kind of stage that rotates about a
center well outside of the goniometer body, and is used for such things
as rotating crystals whose x-ray diffraction patterns are being
measured, or for rotating an optical lens about its physical center (or
perhaps about one of its optical nodes) in pitch and yaw.


Kinematic: US Patent 6,705,019 to Mauro.

Figures 21 and 22 cover a variation that a HSM could make. Two
cylinders whose radii differ by the ball diameter, three or four balls,
and a carrier. Yes, four balls. Why it works kinematically is
described in the patent.


Elastic: 4,759,130 to Goldowsky.

This has to be the shortest modern patent I've read. Anyway, this is
buildable by a HSM, and allows one to adjust angle to 0.001 degree
resolution without the stage moving sideways.


Patents can be obtained in pdf from www.pat2pdf.org or Google Patents.


Joe Gwinn