high static magnet force
high static magnet force
(OP)
Hello,
My company has been building a breakaway device for years now with a pair of magnets firmly mounted to the device. The mating piece is a piece of mild steel. They have the magnets oriented in opposite poles; they (I believe erroneously) call it a Halbach array. There's a steel backing piece to transfer the magnetic flux from one magnet to the other.
During my playing w/ magnets, when all magnets are oriented parallel, the force to pry off the steel puck is about the same as when they are oriented opposites. Now, I must note that it is MUCH easier to get the bloody magnets to orient NSNSNS than NNNNNN. Even stuck to a thick pc of steel, they want to flip flop.
Since the permeability of the N52 magnets is about the same as air, the magnetic circuit that I draw has the same amount of resistors and the same amount of motors regardless of orientation.
My question,
If I had a mild steel rod say 1.25" OD w/ a 1" ID counterbore 3/8" deep. Say the end is ¼" thick. (the whole thing kinda looks like a socket w/o the hole in the middle)
Then I stick a single cylinder magnet (say 3/8"dia, 3/8" tall) in the base of this. Same height as the counterbore. When I stuck this to a steel plate, the circuit that I draw shows much less resistance...wouldn't this mean higher force than simply sticking the magnet to it?
This implies that we could get the same amount of force using less $$$ N52.
I understand that if the ID of the steel counterbore were reduced to near the same size as the dia of the magnet, then it would 'short-circuit' and all the flux could easily travel from the front of the magnet to the rear and it wouldn't need to stick to the mating pc of steel.
Am I hallucinating here? Some of the guys I work w/ have been doing magnets at MIT and I don't want to step on any toes, but it seems like it would work.
I suppose the obvious solution is to go play on the lathe ... In the time it took to write this...
Jason
"Major consumer electronics manufacturer" Mechanical Engineer.
My company has been building a breakaway device for years now with a pair of magnets firmly mounted to the device. The mating piece is a piece of mild steel. They have the magnets oriented in opposite poles; they (I believe erroneously) call it a Halbach array. There's a steel backing piece to transfer the magnetic flux from one magnet to the other.
During my playing w/ magnets, when all magnets are oriented parallel, the force to pry off the steel puck is about the same as when they are oriented opposites. Now, I must note that it is MUCH easier to get the bloody magnets to orient NSNSNS than NNNNNN. Even stuck to a thick pc of steel, they want to flip flop.
Since the permeability of the N52 magnets is about the same as air, the magnetic circuit that I draw has the same amount of resistors and the same amount of motors regardless of orientation.
My question,
If I had a mild steel rod say 1.25" OD w/ a 1" ID counterbore 3/8" deep. Say the end is ¼" thick. (the whole thing kinda looks like a socket w/o the hole in the middle)
Then I stick a single cylinder magnet (say 3/8"dia, 3/8" tall) in the base of this. Same height as the counterbore. When I stuck this to a steel plate, the circuit that I draw shows much less resistance...wouldn't this mean higher force than simply sticking the magnet to it?
This implies that we could get the same amount of force using less $$$ N52.
I understand that if the ID of the steel counterbore were reduced to near the same size as the dia of the magnet, then it would 'short-circuit' and all the flux could easily travel from the front of the magnet to the rear and it wouldn't need to stick to the mating pc of steel.
Am I hallucinating here? Some of the guys I work w/ have been doing magnets at MIT and I don't want to step on any toes, but it seems like it would work.
I suppose the obvious solution is to go play on the lathe ... In the time it took to write this...
Jason
"Major consumer electronics manufacturer" Mechanical Engineer.





RE: high static magnet force
As far as I can understand your description (magnet in the bore), it is obvious that you get a higher force if you correctly close the magnetic circuit with a magnetic conductor like mild steel.
prex
http://www.xcalcs.com : Online engineering calculations
http://www.megamag.it : Magnetic brakes and launchers for fun rides
http://www.levitans.com : Air bearing pads
RE: high static magnet force