RE: [CAD_CAM_EDM_DRO] Re: RoboFac / Stewart-Gough Platform / Hexapod Milling Machine

Simon,

One of the major differences between plumbing pipe and electrical conduit
(besides the price) is that when plumbing pipe is "welded", the seam is left
on the interior because it does not impede the flow of water. When
electrical conduit is manufactured, there is another operation which is
reaming the seam out of the interior so that it will not cause snags or
additional friction on wires pulled in the pipe. You might find it easier
to get a good fit on your next revision by experimenting with electrical
conduit instead of plumbing pipe as it tends to be much smoother.

Just a thought,
Jeff


RoboFac's number one rigidity problem is in the linear actuators. They
have to be able to move smoothly, the insides of the plumbing pipe I use
is not smooth. Therefore, I have to compromise and make the guide for
the screw inside the pipe a little small. This causes some play in the
actuators perpendicular to the long axis.

I've tried to skirt around the rigidity issue so far by taking light
cuts. For hobbyists, I think this is fine.