RE: [CAD_CAM_EDM_DRO] Re: Stewart Platforms...

Thanks, Ray!

>There have been a number of these built over the years since Stewart
>studied and published about the breed. Dave Anderson and I
>ran the NIST cable hexapod at NAMES for a couple of years. There are a

couple of photos of larger cable versions on the NIST site. The latest is a
30'

>triangular platform that moves around a couple of hundred foot work
>envelope using winches.
>

I've seen the photos online, looks very interesting.

>I also visited a friend who works in a rather amazing lab in
>Stuttgart, DE. There were a couple dozen Stewart platforms of various
>geometries. One of them stood 16' tall, used fixed length struts, and at
>least a 2' cube work envelope. A Swedish firm was installing an eight or
>nine axis machine with some Stewart characteristics while I was there.
>You can see just a bit of his work at
>http://www.isw.uni-stuttgart.de/personen/t_franit/primodell/index.html
>(There is a little English flag icon on the bottom of the left
>frame) One of these is in a display cabnet and visitors can press the
>button to see it run around and do it's thing.

Thanks for the link.

>The EMC has the ability to do the inverse kinematics required
>by stewart platforms to take in xyzabc commands and turn them into motion

splines for each of the motors. There are sample matrix files in the

>repository for at least two platforms. There is also the ability to do

forward

>kinematics and a sample matrix for one Puma robot.
>

It seems the EMC is quite the piece of software. I am downloading the CD
ISO right now. I hacked together a 200mhz pc to load it on. Hopefully I'll
get it up and running tonight. I'd seen Paul's setup online before. Very
impressive... does Paul frequent this list?

I've finally got my mind wrapped around the math involved with forward
kinematics... esp. why there can be so many solutions. So, if I understand
you correctly, EMC can handle this? If I were to finish a 3x3 system
tomorrow, EMC could drive it?