At 14:54 04/27/99 -0700, Brian Whittaker wrote:
>  What this all means is that to do it right you must store a lot of
>information about the galvo's performance to improve on the
>basic PID algorithm.

when i proposed a non-pid scheme, i didn't mean to =improve= on the pid
algorithm, but to =simplify= the thing by avoiding feedback. but i must
admit that i don't know enough about the construction of the devices
involved to be able to tell whether this would be possible. whether and how
depends, as you say, a lot on the particular construction.

ge