Tripod

Three axis tripod 2D painting robot

Dear Graham Stabler and all:

I have been observing, I am a newbie, Andrew.

Please help I'm trying to determine the equations to be placed in
Mach 3 for two separate projects.

I want to build a three axis tripod 2D painting robot.
I read your article about kinematics for Mach 3. My 3 motors will be
placed 120 degrees apart with cable etc., could you explain and give
the formula for the equations for a b and c. This will be cable, wire
or toothed belt driven. I know a and b from your pdf I need to know c.

The next project would be 3-D.
Wouldn't a 3-D tripod use (mathematically speaking) three spheres
intersecting at 120 degrees, we then can use spherical coordinates to
determine the radiuii of the spheres for the end lengths of the
cables.
If I am correct could you give me the equations to be placed into
Mach 3.

Best regards,

Andrew