Re: [CAD_CAM_EDM_DRO] CNC'ing both quill and knee

Polaraligned wrote:

>Have a Series II CNC that I am converting. Not my first as I have
>already done a Series 1 machine.
>I am looking to do a 4 axis conversion on this machine. So far I have
>never needed more than the 5" travel of the quill. So the quill will
>have the stepper replaced with a servo and be my primary Z axis. I
>would also like to use the knee like a 2nd Z axis to give me more Z
>travel. The knee should work nice as it is air assisted and has large
>box ways. So....is it possible to make the quill and knee work in
>concert with each other? Should I just make the knee another axis,
>say the B axis, and worry about how it will work with the software
>(mach 3) later?
>
>

The G-code definition of that axis is "W". U, V, W are defined as
linear axes that are parallel to X, Y, Z respectively.

I don't know of any controller (EMC2, Mach, DeskCNC, TurboCNC) that will
automatically move one motor or the other. I know for sure that EMC2
can handle all 9 G-code axes (XYZABCUVW), I don't know how the others
would need to be set up to do that.

One trick that can be useful is to move the knee for tool offsets (EMC2
has an option which will put offsets on the W axis instead of Z - it's
meant for 5-axis machines where the tool is tilted, but it works when W
is always parallel to Z also). This allows you to use the full quill
travel regardless of the length of the tool.

- Steve