Magnet help? - Home Brew Forums

Register Now!
Home Brew Forums > Home Brewing Beer > DIY Projects > Chillers & Stir Plates > Magnet help?

Thread Tools
Old 01-21-2012, 05:57 AM   #1
Dec 2010
Janesville, WI
Posts: 30

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.

Reply With Quote
Old 01-21-2012, 06:14 AM   #2
Stauffbier's Avatar
Nov 2011
El Paso, TX
Posts: 5,118
Liked 1048 Times on 641 Posts

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...
Bier war sein letztes wort dann trugen ihn die Englein fort...

Reply With Quote
Old 04-18-2015, 02:45 AM   #3
orangehero's Avatar
Apr 2010
Posts: 1,750
Liked 305 Times on 192 Posts

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.

Reply With Quote
Old 04-18-2015, 03:03 AM   #4
May 2011
Stow, MA
Posts: 17,817
Liked 3074 Times on 2300 Posts

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...

Click image for larger version

Name:	ab_stirplates_apr_25_2013_02.jpg
Views:	114
Size:	349.4 KB
ID:	271832  

People Like This 
Reply With Quote
Thread Tools

Forum Jump