TackleTour

This may sound dumb but am I the only one that has wondered how an aluminum inductor functions with magnetic brakes? Special magnetic aluminum alloy? As a machinist this would be a first for me.

If this is a reasonably attainable material the next question is why aren't people making custom inductors?

The braking system works because the non magnetic material put in close proximity to a magnet produces a different type of current (eddy currents) that cause the resistance that causes the braking. That is the highly watered down version, I am sure it could much more indepth but that is the easy answer.

But what are the magnets pulling on? I always had in mind that the inductor was what the magnets pulled on the slow the spool.

The aluminum is not affected by magnets, but the electrons in the aluminum are. Anytime you move a electrically conductive material through a magnetic field, you generate electrical current in the conductor. When the inductor enters the magnetic field between the to magnets on the side plate, current travels around it.
Electrical currents also generate magnetic fields, and the magnetic forces they generate act in the opposite direction of the magnetic field that created the electric current. So now you have two magnetic fields "fighting" each other, which for our purposes creates brakes.

smalliesteve wrote:The aluminum is not affected by magnets, but the electrons in the aluminum are. Anytime you move a electrically conductive material through a magnetic field, you generate electrical current in the conductor. When the inductor enters the magnetic field between the to magnets on the side plate, current travels around it.
Electrical currents also generate magnetic fields, and the magnetic forces they generate act in the opposite direction of the magnetic field that created the electric current. So now you have two magnetic fields "fighting" each other, which for our purposes creates brakes.

Looks like a question for an "engineer guy"...not just a Daiwa guy.

Check this out

http://www.youtube.com/watch?v=keMpUaoA3Tg

New marketing should read: "opposing magnetic field braking system"

Wonder if the mag DC braking system in the Shimanos work similarly?

I don't think the magnets are "pulling" anything. I think the magnetic field is actually pushing on the spool.

smalliesteve wrote:The aluminum is not affected by magnets, but the electrons in the aluminum are. Anytime you move a electrically conductive material through a magnetic field, you generate electrical current in the conductor. When the inductor enters the magnetic field between the to magnets on the side plate, current travels around it.
Electrical currents also generate magnetic fields, and the magnetic forces they generate act in the opposite direction of the magnetic field that created the electric current. So now you have two magnetic fields "fighting" each other, which for our purposes creates brakes.

Thank you for this explanation. It's clear as mud.

Seriously though I see what you are saying in a round about way. It does tempt me into modifying or making my own inductors to see what the results are. It seems like ChuckE tried this without success.

tywithay wrote:I don't think the magnets are "pulling" anything. I think the magnetic field is actually pushing on the spool.

X2 ....that is eaxactly what the magforce magnets are doing....but I will let it go at that...as my description of the new marketing phrase "Airbrake" a few weeks ago was totally miscontrued and apparently the magforce magnets no longer play a part in anything to do with SV spools...or at least some want you to believe that they have disappeared.