Hexapod- Hexaslide

I just found a VERY interesting link while doing a Google image
search.

http://www.iwf.bepr.ethz.ch/web/de/forschung/wzm/hexa1.shtml#Resultate

The site describes two interesting ideas, first is the Hexaslide. In
this case rather than have 6 linear actuator legs there are six fixed
legs and 6 normal linear slides fixed to the "ceiling" of the "box".
Sorry am lacking vocabulary. Each leg is connected to a slide at the
ceiling end and a corner of the table at the other. Imagine two of
these legs, if they move together that corner of the bed wants to
move downwards etc..

That seems a pretty interesting concept to me. Most people especially
those with a little cash to spend at least can manage a straight
forward two rail and lead screw type actuator. It should also pack
away nicely.

Now I said there were two ideas of interest. The second in some ways
is even more exciting. This is the triaglide and there is a picture
of one on the site. It looks like a smallish unit but is weilding
quite a large router. This design still has 6 legs but these are
paired up and go to only three actuators in the roof. This gives
three axis machining but to quote the site:

"Likewise a kinetics variant with three degrees of freedom, the
Triaglide is examined. With this mechanism the rotation degrees of
freedom are specified by the fact that the carriages are connected
with the platform with parallelograms. Thus the Triaglide is
interesting as "Low Cost" variant, if no rotation degrees of freedom
are needed. It could be already proven that the Triaglide with very
good repetition accuracy within the range of 1 µm approx. 1/3 more
economically be manufactured can than conventional 3 oh itsnesses."

Sorry for the translation but have a look at the machine and the size
of that router. I for one would prefer to make a machnine like that
then try and build an equivalent conventional three axis mill.

Again software is an issue but less so than for the 5 axis machine.
I think the triaglide is definately in the hobbiest league and with
so little weight to throw around should maximise speed and minimise
stepper/servo sizes.

Graham