Questions about magnets.

[Al Skierkiewicz]

Originally Posted by eugenebrooks

High permeability material, sold under the trade name "mu metal"
is used to shield magnetic fields.

Gene,
Do you have a source for mumetal, we are almost out of the sheet stock and I need to replenish but have only been half hearted about looking.

Ferro fluid is not a magnet it is ferrous metal particles suspended in a viscous liquid. It is most commonly used for speaker voice coil cooling. A few drops squirted into the gap between the voice coil and the magnet structure will do a great job of transferring heat to the magnet body and basket assy without changing the damping of the speaker.

[Greg Young]

That stuff is really cool. I saw on TV something sort of like that which they were developing to use as fluid in off-road racing shocks to essentially change the viscosity in a matter of miliseconds.

Lord Corporation (http://www.lord.com/Default.aspx?tabid=718) has been developing magnetorheological fluid applications for several years. The site has lots of interesting information and applications.

There must be a way to make a continuously variable transmission for a FIRST robot using this stuff, but I haven't come up with one yet.

[Andrew Blair]

Originally Posted by Greg Young

Lord Corporation (http://www.lord.com/Default.aspx?tabid=718) has been developing magnetorheological fluid applications for several years. The site has lots of interesting information and applications.

There must be a way to make a continuously variable transmission for a FIRST robot using this stuff, but I haven't come up with one yet.

Well, Lord is located near us, and at a career fair I got to play around a bit with it. I cannot imagine a way that you could make a CVT with it, but a magnetic clutch is very feasible. FIRST or otherwise, it'd make for some nice shifting tranmissions!