Motor ? for patrick
 

Hi Patrick i have a motor ?.

We use to zapp the magnets in are brushed motors when they got weak, & they got better. Can you do the same to a rotor from a bl motor if the rotor gets weak over time & would it have the same effect as it did in a brushed motor ?.

For the benefit of the rest of us, what does the "zapping" process entail?

gamma rays, I think. And you have to make a laser sound with your mouth during the process.

on the real though: here is a tool by trinity to test the magnetic strength of your rotor http://www.teamepiconline.com/shop/i...?item=TEP3000S

2 pole rotors are easy to be re-magnetized but to my knowledge 4 pole rotors like CC-Neu are pre-magged before assembly, they are much harder if possible to be re-magnetized. The fiber wrap adds up the difficulty.

as far as i know these neodynium magnet rotors cannot be re-zapped.
i belive the older style rotors used an iorn core type magnet. and to re mag them involved placing them inside a huge electro magnet and turning it on, super high current for a few seconds.

that can be made from parts from an old CD drive and an RS project box:wink: it won't give you an accual "gaus" rating, but it makes it easy to compair rotors

I used to work for an oil field tool company a while back and we used to “charge” AlNiCo magnets by placing them in a jig that had a coil. You placed the slug into the aperture and pressed a button that started a small timer circuit that applied a magnetic field to “charge” the slug. Before you charged them you couldn’t even pick up a paperclip, it would stick but didn’t have enough power to pick it up. After the process was done (about 10 seconds) they would hold around 25 # I don’t remember how many gauss it was (about 16 years ago) but it was pretty high. I have also seen the magnet zappers for 540 sized motors they have 2 laminated steel poles that are cut to allow a motor (with the can) between the poles and press a button that starts the machine. When I asked about them I got “it works great” but when I asked exactly how it worked I got blank stares. It looked like a big electromagnet.

Jeff

You really can't "zap" neo magnets -- they require a HUGE magnetic field -- Just the pole pieces to magnetize them weigh about 50 lbs each.

The magnets we use are about 15 times more powerful than "ferrite" magnets used in brushed motors.

I don't remember seeing such a device on my tour of your facility. Can people send in their suspect rotors for re-magnification?

Nope -- the rotor would need to be disassembled -- and that can't be done without destroying the magnets.

The only solution is replacing the rotor.

Note though, Neo magnets don't get weaker over time like Ferrite magnets do. So if they are not overheated, they won't weaken. The only issue is when the magnets get too hot, and then they weaken VERY quickly -- and it's very obvious.

Thanx!

Patrick

Cool.

Also, I seem to remember vibrations weakening magnets. Is this true? And is the vibration from a vehicle bouncing all over the place enough to affect them?

Not Neo magnets, as far as I know. We've never seen a magnet that was weakened at all -- unless it was overheated. Heat is really the only enemy of Neodymium magnets. The magnets we use are rated to 200C operational, so it's pretty tough to get them too hot. :)

Thank you for the info patrick :smile:.

:surprised: just wanna make sure thats not a typo... there rated for 200 Celsius!?!? thats 392 Fahrenheit!

I would really like to know some of the ins and outs of magnet zapping. When I worked at the oil field tool place the guy that designed the jig quit months before I got there and most of the guys in my unit had no interest as long as it worked. I remember that the coil was not very large maybe 70-100 turns of 12 Ga. magnet wire. Once you started the process you would see the slug jump a little about 3 times.

I saw How it's Made and they were charging some horseshoe magnets across 2- (aprox) 12" square plates that looked 1/2" thick They passed a current through the plates IIRC ~200A and ~7-10V.

I have played with some electromagnets before but I haven't really read anything indepth on this subject and there is not a lot on the net about it. I know it's not the not the original question but it would be great to get a long exciting technical explanation.:mdr:

One question I have on the brushed zappers is since you still have the magnets in the can doesn't that effect the flux across the magnets or is the field so strong that it doesn't matter.

Jeff