Squirm Gears What happened to them?

I think first is like you stated cost. Second, machine builders have come up with what many consider reasonable table position feedback (ex: linear scales) to take up the slack. At least that's what the market bears these days.

-- Bill

pretty interesting article, I wonder if the zero backlash claims held up

That was an interesting article. I remembered reading it years ago, but until now it did not show up on a Google search. Now that the old magazines have been scanned in, Google can find all those old articles.

Thanks Sam for those links.

I wouldn't be surprised to see that design in a four or five axis VMC "Zero Backlash" rotary set up.

Cross-Slide wrote in news: snipped-for-privacy@z7g2000yqb.googlegroups.com:

That brings back some memories. I worked on trying to develop a way to machine the "Squirm" shaft way back in the '80's. We had a machine with the right kinematics, but no way to control the axes of motion to the level of precision required.

The worm form in the shaft is/was a problem to manufacture. The design isn't very scalable and there are other simpler ways to deal with the problem of backlash nowadays. You could just use and integral servo motor and glass scales for example.

Yep. Most of the Japanese builders are already doing direct drive rotary axes. Powerful, accurate, reliable, and FAST.

We used such a "squirm" gear for a prototype product except they called it a "Harmonic Drive". I cannot remember the manufacturer but it was very expensive. Turned out, we did not need the accuracy it gave and a worm drive gave better size of the unit. The Squirm gear had low speed and low load. I still have it somewhere.

I have heard of harmonic drive; I just don't recall if that was in context of a sci fi movie or show though as opposed to mechanical; still I like the link to the pop sci page, it might be something to adapt and play around with

A Harmonic Drive is quite different from a Squirm Gear. Similar in that they can achieve low to zero backlash.