Re: minitetra?

[Fred Proctor <frederick.proctor-at-nist.gov>]

Till Franitza wrote:

> When i choose minitetra.o, the steppers move, but not in the way i expected
> them to. No matter what the trafo and its parameters are, when i go in
> x-Direction, i expect more than one motor to move.

The minitetra.o controller has the Stewart platform kinematics built in.
You can see this in emc/src/emcmot/Makefile, for the minitetra.o target,
which links in genhexkins.o instead of trivkins.o. These are the generic
hexapod kinematics instead of the trivial kinematics, respectively.

You should run "yemc" as the DISPLAY. yemc has the concept of world v.
joint coordinates, which you can select using a menu somewhere or via
the "$" key. In joint coordinates, the axes are labeled 0, 1, 2, etc. In
world coordinates, the axes are labeled X, Y, Z, etc.

Note that jogging only works on joint coordinates. The keys for these
are q/a for the 0th axis, w/s for the 1st, e/d for the 2nd, etc. See the
pattern?

If you want to see true X world coordinate motion, go into MDI mode and
do G0 X1.

Jogging in the world coordinate frame is another one of those things
that makes us want to redo the motion controller.

> Brian register might know this, but i dont have his e-mail-address.

Brian is at register76-at-yahoo.com or register-at-ufl.edu. He's graduating
with his masters degree from U of Florida, and taking a real job
according to his advisor, so he may be gone. Check out Brian working on
their hexapod:

http://SAMM2.me.ufl.edu/SAMM/members/brian/brian.html

--Fred