Martin Eastburn wrote:

Polar ?
Martin

Axes 4,5,6 are typically rotary axes. I've only used a 4th axis a few
times and when I did I cheated and configured it as a linear axis based
on the circumference of what I was machining to simplify the CAD/CAM
work.



On 7/21/2012 7:14 AM, Pete C. wrote:

Jon Elson wrote:

DoN. Nichols wrote:


Non-Cartesian? -- You mean like the hexapod? I believe that was
one of the early experiments built around EMC (what LinuxCNC used to be
called.)
There's hexapods (Stewart platforms) and hexaglides, and 4- and 5-axis
machines, as well as robots and SCARA arms. There are also other schemes
that can be assembled from a combination of rotary and linear axes.

LinuxCNC can control all of these, although the more unusual ones
require writing some code. Also, this flexibility allows you to
correct for inaccuracies in the machine construction, as Stuart Stevenson
at MPM demonstrated with a 5-axis Cincinnatti mill in his shop.

Mach3 supports traditional 4th-6th axes just fine. No hexapods though.


The big difference between Mach and LinuxCNC in this are is LinuxCNC
can control all of these machines in Cartesian space, with standard
XYZ G-code, and let the kinematics routines figure out what crazy
angles the joints need to be in to reach each position. So, you can
even JOG a robot in Cartesian coords. Mach just treats all axes
as numbers, so you'd have to program all axes of a robot numerically.

Jon

Yes. I'll worry about that when I try to run a hexapod. Not holding my
breath on that one though, I expect I'll remain in the traditional
cartesian space for the foreseeable future.