Re: Open (i think) design for a parallel robot (reprap may be interested)

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dennis Schmitz"
<denschmitz@...> wrote:

>
> I'm not sure why the distinction. It's still the same number of
> operations. Matrices are just an easy form to work with in code as
> well as conceptually. Of course I spend a large part of most days in
> Matlab, so I might be biased.

What operations? In the marix formulation I assume you are solving an
equation system. I've basically done then directly for a specific
case (the machine's configuration) and I end up with an equation that
amounts to A^2 = b^2 + c^2 I don't solve it I just evaluate it.

I'm also a matlab user but my machines won't run on it :(

>
> I find the matrix to be a more general form, probably because I'm

used to it.

It is a more general form, you are representing a sytem of vectors
generally.

> I saw the stuff about the clevis, but I think the ball with
>self-lubed> plastic bushing is a simpler design.

Problem can be a lack of movement, the red delta at the bottom of my
page uses a pair of half sockets and a spring to keep them engaged,
that gives lots of movement. The igus ball joints don't have a lot of
motion as stock unfortunately, perhaps you know of better ones or
maybe I misunderstand the configuration. As it happens I don't intend
to use clevises in my triaglide model, I'll be using the bearing
cartridges from the arms of about 30 dead hard drives. Built like this:

http://www.designpreis.ch/bilder/medien/download_bilder/Force_Dimension_download.jpg

I assumed you were talking about hexapods because you posted a link to
a hexapod.

Graham