Dennis Schmitz wrote:
All of this talk of water jet cutters and occasionally lasers led me
to this website.
Apparently you're supposed to buy your own plasma torch, but in any
case, it's a very spartan design of an xy table with a little bit of
z. They claim accuracy of 0.0005 in the xy, making me curious how they
built the actuators and bearings.
This is the classic confusion between resolution and accuracy. There's no WAY
they can provide ACCURACY of .0005" in a machine that size. It would be
VERY expensive to provide such accuracy in a coordinate measuring machine
that size, if built of granite and air bearings, and kept in a temperature-controlled
room. OH, but wait! They DO NOT claim such accuracy. The specs say "resolution",
and that is perfectly reasonable.
I would guess an initial accuracy over the whole work envelope of .1" at best, as I'm
sure they do the minimal amount of calibration. They probably use a square to
set the orthogonality of the axes, and that is ALL.
I'm pretty sure the linear actuation is rack and pinion, and the axis looks like
bearings roll along steel channels.
Jon
