recharging magnets

[max corrigan]

I don't know if this a dumb question! but i was given an old DTI magnetic holder but the magnet has hardly any strength, certainly not enough to trust holding a DTI or likes, is there any simple way of recharging the magnet on these things,i can get at the magnet with no problem! and it would then be a handy tool! or shall i just aim it at the nearest corner
Regards Max.........

 

[JonnyD]

You can recharge them, but with most consumer unit it's not enough of a charge.
It's easiest to just replace it with a Neodymium magnet from Magnet4Less.com

 

[rleete]

Not really practical for a D-I-Y er. It takes fairly large coils, and quite a bit of current. You'd spend more to make the device than buying a good Starrett base would.

 

[rake60]

I did build a magnet recharger once.
It was to rejuvenate the magnets in antique engine flywheels.

Each of the coils contain 720 wraps of 12Ga solid copper wire.
When I built it the cost of the copper was about $120USD.
It CAN be done, but it is a pricey venture.

Don't throw that old base into the corner just yet.
It could be a simple bit of misalignment of the magnet or a varnish build up on
the bottom surfaces. Clean the faces with scotch bright.
Does it have an off / on lever or button?
Try going part way, or past the on position to see if it makes a difference.

Rick

 

[max corrigan]

Thanks everyone for your suggestions it does not seem worthwhile pursuing costwise
it was just a thought i had that it might be easy to do, considering i only have to use a magnet near the lathe such as picking up cast iron filings useing the paper bag method, and everything thereon seems to be magnetised cutting tools and everything else! those switchable magnetic bases don't seem to do this

Rick i did take the base apart and cleaned everything, the magnet inside is about
1" dia by about 1.25" but the pull on a piece of steel is not very strong! it would'nt be enough! thanks for your suggestion though, i think it is destiny is in the corner, on the heap
Regards Max..............

 

[bentprop]

If it's a cast iron base,you could probably turn it into a dandy v-block!

 

[Stan]

Some places that have magnet chargers.
Shops that repair magnetos (such as on older farm tractors)
Museums that restore old engines
Instrument shops (especially aircraft)

 

[rake60]

If we were on the same side of the pond, I say send me the magnet and I'll
rejuvenate it for you.

Shipping across the pond would be expensive as well.
I have never tried my home made flywheel magnetizing machine on an
indicator magnet before. I will be trying that very soon!

Rick

 

[Kermit]

If its a steel alloy type magnet you might as well trash it. OR purchase about 100 feet of 12 gauge wire, wrap it around the magnet solenoid style and short out a car battery with the coil.

Be careful you are not holding the wire when you do this. It's gonna burn up, but the amps that pass in that one second will remagnetize that core.

Steel magnets become plain chunks of steel if they are struck or dropped on a hard floor.

A Neo type magnet would make a very cheap replacement. One word of advice about the use of magnets with steel and cast iron. Annealed steel will not hold a magnetic "charge". Hardened steel WILL HOLD a magnetic charge. If you do not want to magnetize a hardened bed way, never place a magnet on it. Only a hammer or a blow torch will remove the magnetism from "hardened" steel.


I'm a newbie machinist, but a veteran electronics technician,
Kermit

 

[max corrigan]

As the original poster of this i would like to thank everyone that replied to this problem,i have read all, thought, then considered, and then aimed it in the farthest corner and bought a mitoyota (sp) of ebay complete with DTI
regards Max.................

 

[rake60]

You won't be disappointed with that choice Max!

I won't use anything but Mitutoyo bases at work.
I have 5 of them there. Last one I bought cost me $182 without the indicator.

Great choice!

Rick

 

[ksouers]

As the original poster of this i would like to thank everyone that replied to this problem,i have read all, thought, then considered, and then aimed it in the farthest corner and bought a mitoyota (sp) of ebay complete with DTI
regards Max.................

Hope your aim was good