Instructables

What Can I HacK to Find Magnets? The POWERFUL the better.

Just wondering where I can find magnets for a project.. I was thinking about trying to make a magnet motor . Button shape magnets would work great.. But I dont really want to buy magnets cause the kinda cost alot. So I just want to start with what I can get until I get it working. Then I'll invest in magnets later. Since you guys/gals take alot of things appart I'm sure you know where I can start looking. thanks.

Picture of What Can I HacK to Find Magnets?        The POWERFUL the better.
Hard drives are the best place to find strong magnets. Your average used speaker or motor will have magnets of the ceramic type, with a smaller ratio of strength to weight. It's possible to find neodymium magnets in magnetic toys if you're lucky enough to find some at a yard sale.

However, you might take another look at buying your magnets now. There are a few places you can buy magnets without being charged an arm and a leg. To avoid getting ripped off, be sure to calculate the unit price. The two examples below are fairly reasonable, but some people's prices are ridiculous.

For example...
Say you see some little grade N35 magnets for sale.
Length: 5 mm
Diameter: 12.6 mm
Price: $12 for 25
Shipping: $5

You go to Google and type in this calculation:
(12+5)USD / 25 / (12.6mm/2)~2 / 5mm in USD/cu in
You find out that these magnets cost $56 per cubic inch.

On the other hand...
This other deal sells bigger grade N42 magnets.
Length: 1 in
Diameter: 0.75 in
Price: $14.46 for 6
Shipping: $10.42 (lots of packaging)

(14.46+10.42)USD / 6 / (0.75inch/2)~2 / 1inch in USD/cu in
So $29 per cubic inch.

Also be sure that you choose the right shape for your application. Small thin magnets packed together with poles pointing in alternating directions provide a powerful grip on a thin surface, while one tall cylindrical magnet might be better if you need a deeply penetrating field.

A CD/ DVD drive has 2 small Neo magnets near the lens.
wolfram74 BobS1 year ago
Thanks, I needed such small and powerful magnets.
signposts4 years ago
Personaly i destory some magnetic toys, eg. magnetics, geomag etc. the magnets in those are quite powerful and easy to get if you have a knife. Although the problem is they are quite small.
tezzz5 years ago
Take the magnet out of a shaker torch. Really strong! About the size of your thumb. I stuck one to the stove and couldnt pull it off straight, had to slide it off.
dsupanga5 years ago
for the homopolar motors you can see here you can hack the magnets from these cellphone cases with magnetic flaps/locks. i found that some are made of metal and others made of ferrite. they are very powerful., the ferrite, i stacked 7 pieces with aluminum foil and it worked. i found that there are flaps with with 4 magnets which are made of metal. stack 7 pieces of these are and no need for aluminum foil..
Kiteman5 years ago
If you're just making a simple motor, you don't need super-strong magnets. Try prising the circular ceramic magnets off the back of fridge magnets. Don't bother with the flexible magnets; their fields are too complex to be useful for a motor.
andy5 years ago
Some of the higher end ear buds have teeny ones, but you have to fight them out, they are normally strongly glued in place. Drew
Redrockers5 years ago
buy cheap toys with magnets in them from the dollar store
djmachet5 years ago
hard drive magnets are powerful especially because of their size (very useful if you're limited by height or don't want something bulky hanging around. Speaker magnets are powerful but bulky... haven't hacked open a microwave yet so would be curious to see them
old microwave each contain two powerful magnets and reuseable copper wire appliance repair stores might have loads of them at little or no cost for non fixable ones
fwjs285 years ago
speakers...hard drives...cd drives (towards the laser)....or you can just buy neodymium magnets...
altomic5 years ago
for inexpensive/free try - computer hard drives speakers