How to separate magnet from shaft?

[scarletboa]

Originally Posted by littlegiant

Oh and by the way i just had to say this. Kb45 owners shouldn't be worrying about the rotor magnet debonding from the shaft at all. The damn magnet just could not be seperated from the shaft no matter what I tried.

my rotor seperated from the shaft in my KB45-8xl. now, i'm debating whether or not i should try grinding the shaft to 5mm on my KB45-12l.

[littlegiant]

Originally Posted by scarletboa

my rotor seperated from the shaft in my KB45-8xl. now, i'm debating whether or not i should try grinding the shaft to 5mm on my KB45-12l.

Oh man, I am so jealous of you. How did you seperate your rotor magnet from the shaft? I've been trying to do that. I want a new rotor shaft. I think you got lucky. Did you overheat your kb45? Do the KB XL rotor magnets come in a single piece?

:D

[NovakTwo]

We separate the shafts from the magnets by putting the rotors in one of our ovens at extremely high heat.

This heats the epoxy until the shaft can be pulled out.

[littlegiant]

Originally Posted by NovakTwo

We separate the shafts from the magnets by putting the rotors in one of our ovens at extremely high heat.

This heats the epoxy until the shaft can be pulled out.

Wun the magnet get demagnetise?

[NovakTwo]

Originally Posted by littlegiant

Wun the magnet get demagnetise?

Yes. That's why we separate them.

Then we can re-magnatize the magnets.

[littlegiant]

Originally Posted by NovakTwo

Yes. That's why we separate them.

Then we can re-magnatize the magnets.

OoooH I guessed that part right.

Anyway how do you magnetise a demagnetised magnet?

[J57ltr]

With a strong magnetic field. When I worked for Western Atlas we had a Zapper that we plugged in and set the magnet into a cradle that was surrounded by an electromagnet. It was set for about 3 large pulses that would take a AlNiCo magnet from being so weak that it couldn't pick up a paperclip to strong enough to pick up a 25 lb weight. I am sure it would be the same type of operation but the poles would be oriented so that the N and S are perpendicular to the length of the rotor. I would like to know exactly how this is done also. Things like how many amps @ Volts and how many turns are in the electromagnet and what gaquge the wires are.

Jeff

I suggested using Locktite for retaining sleeves to glue a rotor back onto the shaft after it came loose to a friend of mine and it worked great, but you have to heat it to over 400F to get it to seperate.

[NovakTwo]

Originally Posted by littlegiant

OoooH I guessed that part right.

Anyway how do you magnetise a demagnetised magnet?

With a big, expensive machine.....