Re: [CAD_CAM_EDM_DRO] Alternative Linux for EMC?

Alan Marconett KM6VV wrote:

> Thanks Paul,
>
> It will be a while before I do anything. I would like to see the
> source code at some time. I'm interested in the g-code, and
> bresenham implementations. I've tried some code on a PC, not cutting
> anything with it yet.

Bresenham? The Bresenham line and circle generators are for raster
graphics
systems, and other discrete grid methods. They really don't have much
application to numeric control of motion. (You could make great use of
them
for crash protection, or making voxel maps of the remaining material
after a
cutter has moved over it, though.)

EMC does not use any discrete methods like this. It uses some methods
more like the ancient DA, where linear moves are interpolated by adding
small increments together, and I guess DA-type circle generating
routines,
too. I have not looked at that part of the code, because it was not
where difficulties might lie. Also, with so many variables such as
acceleration,
multi-axis velocities and the actual vs. desired position, plus blending
of
short moves, the code is bound to be deeply obscure!

I spent much more time looking into servo stability and following error
concerns, which has paid off quite well.

Jon