rolamite

[Art Ransom]

see http://www.rexresearch.com/wilkes/1wilkes.htm for details of the rolamite. This seems to be a much easier and accurate system of motion control. Anyone have experience with it?

[Torque1st]

Much ado about nothing comes to mind...

The claims read like a lot of perpetual motion devices to me. In other words; -BS.

Just my 2¢

[svenakela]

This is old school, nowadays we use bearings or ball beds (as in a linear guide).

[silverfox]

The information in the link is from Popular Science (March 1966) - I would think that if it is as good as they claim, someone would have made some use of it in the last 42 years.

[Mike Everman]

I've had some fun with these type of flexures. The things that bothered me about the Rolamite were mainly that if it were used as a linear bearing element, that the flatness would be dependent on circularity of the rolls and thickness consistency of the banding. A further problem is that a payload puts tension directly into the bands, creating a less than optimal spring-mass system.
Attached is a paper I did for ASPE explaining my MacroFlexure bearing element, which is similar to a Rolamite, but actually quite different. It can do some amazing things, but is really only useful for a small list of cases, mostly semiconductor metrology Z motions, where you might actually be concerned about an arc-second of tip-tilt throughout travel, which is rare upon rare. ha.
Neat, and fun stuff, but not a real barn-burner when it comes to a product.
You can see both in Alex Slocum's new MIT textbook.

[Erik Brinkman]

First, I would like to assure "Torque1st"
that he can be confident that nothing coming out of Sandia Atomic Labs, including the Rolamite .... is "BS".
If you go to Wikipedia you can see some detail on the subject.

The issues with the Rolamite are about people's expectations. People do not expect that motion can have no slipping, sliding or rubbing and display ONLY rolling friction. It seems very counter-intuitive and thus easy to dismiss.

Rolamite technology is in fact in use. Because of its extreme reliability it is used your car's airbags as the inertia trigger mechanism. It was originally used as a safety for the trigger in the H-Bomb. It is still being used in that application.

The limitations were that the mechanism was linear only.
Sandia spent a great deal of effort in making the motion rotary because most all mechanical mechanisms are rotary. They were unable to make that breakthrough.

That breakthrough was made about ten years ago by IDS-Research.

link: http://www.erikbrinkman.com/scroller/video.html

On the left side of the page there is a link to the ScrollerWheel REPORT.
It is very extensive and detailed and should be read before application.
If you want advice on applying the technology, feel free to contact me.

[Art Ransom]

The simplecity is unreal. What I was interested was the possible use of the rolamite concept in controling axis movement and gear reduction. The band becomes the critical factor in being able to handle the load. The only commercial application I have found is for a postal scale.
Three articles in Popular Science and development by and patent held by Sandia Labs tells me this is not some BS idea but I would like to find some real world use and data before I jump into building a indexer using it.

[Erik Brinkman]

The applications that I am aware of are Military and I cannot speak of the details of such matters, but I would suggest that you read the ScrollerWheel Report after which we can talk about your application. If your understanding is such that your application is feasible, I shall be pleased to help you reach your goal.

[Torque1st]

Erik, I worked with some applications from Sandia also. Unfortunately I have seen a lot of BS and other things over the years. It is a good lab for the most part but not everything is wonderful that comes out of there. Sorry but I can not mention specifics either.

[Erik Brinkman]

Your assertion that some of what comes out of the Sandia Labs is "BS"
is surprising. I do not mean to offend, but I find it quite unlikely.

You see, developments go through an exhaustive peer review process,
so what is released is extensively reviewed by highly qualified minds.
Every possible question and/or objection is addressed.
The finding from the lab are thus supported by the scientific community.

It is hard to imagine that your judgement that some releases are "BS"
is likely to be in any way more valid than the community as a whole.
Could it be that you instead dismissed what you did not understand ?

[Torque1st]

Not hardly.

I am well aware of the processes there. Apparently some people have more faith in peer reviews than I have.

I also don't just jump on "supposedly" new ideas even if this one was published back in 66. Read the piece originally linked to and tell me all the claims are true.

[Erik Brinkman]

Whether you have faith in the peer review process is of no consequence in that the review process is not based on faith. It is an objective review process by many of the world's top scientists (done via the DARPA net) and is based on provable fact, not faith. The very purpose of the peer review process is to eliminate any chance of "BS". Am I to suppose that the considered reviews of scores of the countries best minds is inferior ?

What claims to do you believe are false ?