This method was developed by the late Bill Muller for his motors. Make a frame or mold of the exact size of magnetite core you wish to cast, and line it with a material that will allow you to get the core out after it sets up. Make sure the end plates are made of .125 inch plastic sheet. Mix your magnetite with a slow curing, high temperature resin. Mix as much magnetite into the resin as possible while it is still malleable. Fill the mold and place the end plates on each end, and then place a strong, NEO magnet on EACH SIDE of the mold. The NEO magnets should be at least as large as the magnetite core you are making, and should face each other in the attraction mode, so that all of the particles of magnetite line up, and TOUCH EACH OTHER as the resin sets. This also aligns the magnetic domains in the iron so they are all parallel in the finished core.

Any other method yields very poor results.

When the resin is set (24 hours), the magnetite disc should be able to magnetize up to at least 2500 Gauss and operate with a very narrow hysteresis curve. It will be a complete "non-conductor" so "eddy-currents" will be very low.

Bill Muller used these cores in his motors as a cheap substitute for Metglas Cores. They have many of the same high-speed switching characteristics, but their magnetic permeability is much lower.

That is it. No more questions. Good luck.

Peter

Looks like Metglas offers free samples. Might be worth trying it out.

http://www.metglas.com/products/page5_1_2.htm

Aphasiac.