This is the working branch; if this is your first time here you probably want to go to our public website first.

This really needs to be changed to a new repository that talks about Gluss Robots rather than the Gluss Pusher per se.

Please see Sprint 3 for the latest progress.

Attempt to create simple, cheap linear actuator for giant robots and other tasks

This Repo is to hold research related to the invention of a new kind of linear actuator.

As part of the PIFAH project, this is completely open-source (both hardware and software) and everything be released either under Creative Commons Share Alike, or the GPL.

As explained in the PIFAH/PIFAH repository, we welcome your contributions and participations. Contact me to see how to participate.

I would like to build robots based on large numbers of very simple components that can lengthen or shorten themselves. Buckminster Fuller invented the Octet truss, a beautiful space-filling structure of alternating tetrahedra and octohedra. Or perhaps it would be more accurate to say that the universe invented and Bucky promoted it.

If we imagine a "truss" that acts like a "glass" we get a "gluss" that can move like a "slug". That is, I want a system that can ooze about like a slug.

Linear actuators are standard components that can be purchased off-the-shelf. However, they are rather expesnsive, at about $100 a piece. They are also more forceful and more precise that what we need to build an experimental "gluss". Although it would be wonderful to spend $10K to build a power 100-element gluss, I think it makes more sense to attempt to use simpler components.

I also believe there is value in general for linear actuators in a cheaper, weaker part of the design spectrum. Such actuators might be called "mechanisms" rather than "machines" in technical parlance. A machine deals with forces, a mechanism is concerned only with positioning.

http://en.wikipedia.org/wiki/Halbach_array

I don't understand why there isn't a good online simulator---perhaps I should write one. This looks like it might work:

http://www.mare.ee/indrek/ephi/

http://en.wikipedia.org/wiki/Tubular_linear_motor

http://eprints.whiterose.ac.uk/852/1/wangjb15.pdf

I'm afraid I don't know enough about magnetism to really follow the equestions. The purpose of this paper is to provide a model for linear permanent magnet machines. I think it would be very valuable if you trying to optimize a design, or understand the force/current/voltage relationship. It is hard for me to understand exactly how to use this research.

This firm seems to make great ones, but doesn't list prices, so one can assume they are expensive:

http://www.linmot.com/fileadmin//user_upload/Downloads/databooks/0185-1100-E_1V0_Product_Overview.pdf

Here is a nice description:

http://machinedesign.com/news/linear-actuators-get-servo-look

So the terms "linear motor", "direct drive actuator", "tubular permantne magnet motor" are all used in this area. The central rod should probably be called the "thrust rod".

This PhD Thesis looks excellent by Bryan P. Ruddy looks excellent:

http://hdl.handle.net/1721.1/78177

Reading Ruddy's dissertaton, it seems like the real contribution that I can make here is to move this out of the laboratory and into the realm of practice. If we can make this kind of work available to hobbyist and the maker moverment, it seems that we could make very rapid progress on a really fundamental technology.