HELP! Rare earth magnet in a stir plate

[RegarRenill]

So, at some point, my other half tossed all of my old harddrives. Will a round (disk) rare earth magnet work in a stir plate or should I try to find a bar shaped one?

 

[narcolepticsniper]

As long as the magnet holds the stir bar through the glass of your flask (or whatever media will be holding your starter), it can be any shape. Test it out first, make sure the stir bar and magnet are strong enough to hold together.

Give it a week or so of looking - recycling centers and dumps are good places to find a free hard drive - you'll have to pull it from a tower - hell, ask a buddy at work.

 

[Beernik]

Try a Facebook shout out to friends. I got some old cellphone chargers for projects, including my stir plate, that way.

 

[Gear101]

I got mine from a computer repair shop, cost me like 5usd for two ~1" banana shaped ones. Shops have all types of old drives around.

 

[jtratcliff]

use 2 round ones... one on either side of the fan. Might have to alternate polarity to make it work right.

 

[krazydave]

I use round ones and like them much more than the hard drive magnets.
I glue a big fender washer to the fan first then I can stick the magnets tithe washer to find the best position. Once I find it, a dab of epoxy holds em there.

My magnets are probably about 1/2" round, maybe slightly larger...