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Home Brew Forums > Home Brewing Beer > DIY Projects > Chillers and Stir Plates > Magnet help?
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Old 01-21-2012, 04:57 AM   #1
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Default Magnet help?

I have ten (10) rare earth magnets bought from a jeweler. They don't grab both poles of the stir bar. WTF? Did I make a bad choice in magnets? I thought all magnets had a N/S pole and would automatically grab both ends of the stir bar. I have made several other stir plates that worked perfectly with rare earth magnets from hard drives. These are straight rare earth magnets that jewelers use. Any experience and insight as to why these magnets only grab one side of my stir bar is appreciated.

Why would a magnet this strong only attach to one side/pole of the stir bar? I used a flat washer on the fan with 6V DC adapter. Also, I have 1/2" spacers in between the stir bar and magnet/fan. I am t a loss as to hy the rare earth magnet only grabs one side.
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Old 01-21-2012, 05:14 AM   #2
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Try using only 2 magnets. Keep one in it's positon and keep flipping the other one until it's at the opposite pole so that one mag is sitting with north up and the other is sitting with south up..

And seperate them both by about 1/4 to 3/8 of an inch...
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Old Yesterday, 02:45 AM   #3
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Has anyone tried two flat bar magnets with the poles reversed? If so, does it work better than the button magnets?

These magnets:


Like so:

[-----( + )-----] [-----( - )-----]

Thoughts? I'm wondering why everyone uses the button magnets.
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Old Yesterday, 03:03 AM   #4
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I used pairs of 1" x 1/4" magnets end-to-end on my builds, works great.
They'll swing 1 to 2 inch bars full blast without tossing them...

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