Got a few samples today of some material we plan on testing to see if it offers any advantages in heat transfer in motors, and if it has any value as a faraday ring. The silver pieces are aluminum and the copper colored is copper.

For a second I thought you melted a penny.

The material is an open cell foam made from several different materials. The 8 percent density aluminum foam has a compression strength of 360 PSI and has a surface area up to 50 square inches per cubic inch. In a larger diameter motor we will be able to fit enough material to get around 800 square inches of surface area to help dissapate heat as air flows through the motor.

Definitely curious how it will compare to a solid hunk of similar metal.

Where in the motor and what thickness material?

Where in the motor and what thickness material?

Imagine it being installed like a faraday ring. Except the forced air will have to travel through the material to exit the exhaust vents in the backplate. The idea be hind the foam is it creates turbulance in the air flow, increasing heat transfer. The material is currently used in other heat transfer applications and offers a substantial increase in cooling over convential finned heatsinks

So they will be at the base of the pole? Was just curious as with the thickness it didn't appear they were going to be a full pole sleeve. Seems like an interesting concept, interested in seeing the results.

They will be positioned between the coil and the magnet ID. The pole is already close enough to the coil that it provide pretty good heat transfer. We are trying to fill the void and increase surface area between the coil and magnets as air is horrible for heat transfer. We are going to try some top plate machining similar to what JBL started in the '70's along with some machining on the back plate that will allow air to forcefully flow through the motor assembly rather than just be compressed which is happens no back plate exhaust vents are present.

We are going to first test this on the big MMAG motor. One with and one with out the foam inserts. A Klippel analyzer will be used to measure the temperature differences on each of the motors. If we see a noticeable increase in performance it will become a standard feature.

What ever came of this? Did you ever get a chance to test it in a completed motor?

no, too expensive to manufacture