Re: RoboFac / Stewart-Gough Platform / Hexapod Milling Machine

Guys,
I'm really not familiar with your project, but I know a little
about materials. Try looking at "seamless steel tubing", which is
available in dimensional sizes, and is not made for containing water
or electrical wiring.

Marv Frankel
Los Angeles

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Jeff Goldberg" <jeff@w...> wrote:
> 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.