Re: [CAD_CAM_EDM_DRO] Re: Open (i think) design for a parallel robot (reprap ma

Carl Mikkelsen wrote:

>Does EMC only handle trajectory planning in XYZ Cartesian
>coordinates, or does it also handle G-code interpretation and motion
>planning for 5 or 6 axes?
>
>

It does six, but they are not totally coordinated. By that, I mean that the
commanded move velocity is only calculated from the linear axes. So, if
you had a 3" round part on an A axis, for instance, and asked for a
velocity of
1 IPM, and the move was 360 degrees rotation of the A axis at the same time
as a 1" linear move in X, then the move would take 1 minute. But the total
move length would actually not be 1", but something like 9.5", and should
take 9.5 minutes if you are concerned about velocity through the cut.
The problem is that RS274-D has no way to specify the radius of the tool
to the rotary axis' center. I think there has even been a new feature added
to the interpreter to allow these radius calculations to be performed,
but I'm
pretty sure this is in the interpreter, NOT in the traj. planner. (If
I'm wrong
on this one, let me know.) Or, maybe I'm just thinking of inverse-time
specification of the moves. There was some discussion on the EMC list
of this
about 2 months ago.

Jon