Re: Stereolithograpy revisited

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@...> wrote:

> Actually, galvanometer-mirror drivers can be found on the surplus

market (they used to use them in direct-writing oscillographs 50 years
ago) and they wouldn't be that hard to make, either. I have some
little ones, basically two wires suspended in a magnetic field, with
a tiny mirror glued in the middle of the wires.

You are right, you can get galvos surplus but that is only half of th
story. You also need amplifiers and more importantly software. If
you want to do precise work you also need to correct for the focussing
lens, the lens is normally put after the mirrors so that the angled
beam at the back focal plane causes an offset at the focus but one
which is still relatively vertical. Laser light show software doesn't
have this facility although I am sure the CAD could be suitably warped
or the g-code generated in a special way.

The type of galvos used for this sort of work tend to be servo types
with a PM rotor and a capacitive feedback sensor IIRC, there is a
great site showing some homemade ones of these doing a nice laser
light show but again a light show is not quite the same as STL.

Anything is possible

Graham