Jerry Frost wrote: > It's one of the 4 link models; Watt linkage maybe? It's there, I saw it. > <grin> > > I'm going to revive and maybe upgrade my erector set so I can experiment > with some of the linkages. One of the 8 link models is suposed to have > "perfect" one dimension movement. That was by Peaucelier. Very ingenious, but what a contraption!