Products With Small Strong Magnets In Them

[kevnlis]

As the title says, I would like suggestions of products that have small strong magnets that could be removed and glued to a case fan to make a stir plate. I have the magnetic stir bars but no magnets I could find were strong enough to spin them properly!

 

[domonsura]

A dead hard drive has them. I use one ripped out of one of these in my stirplate, a little tricky to get balanced on the fan, but it works fine. If you have a local pc repair shop, they may even be able to help you out with the dead hard drive. All you have to do is rip it to bits.


edit : Shpelling

 

[user3673]

This is what i used for mine, Linky purchased from jaycar last week for $15.

Just stacked 2 together for each side. I cut them out of the plastic, it has 9 rare earth magnets in the strip, I use the left overs to hold my stir bar in place.

 

[Wakt]

Personally I found the HDD magnets very hard to use for stirplate use when I built mine. I pulled apart 3 HDD's only to find the magnets all different sizes and couldn't use them. On top of that they are very hard to get out as one HDD had the magnet somehow electroplated to the case.

Anyway my solution was to get 2 bar magnets with north and south pole polorisation from Jaycar at 80 cents each and mount those on the fan. The key I found to getting it to work reliably was the distance from the bar magnets to the magnetic stir bar in the jar. There seems to be a sweet spot that works perfectly I find. Hope that maybe helps you and saves you some times and HDD's.

 

[Gulf Brewery]

I used the jaycar magnets too - I don't see the need for really strong magnets as once the liquid is stirring, it doesn't take much to keep it that way.

Cheers
Pedro

 

[floppinab]

Anyway my solution was to get 2 bar magnets with north and south pole polorisation from Jaycar at 80 cents each and mount those on the fan.

Just beware Wakt, I went down that route with some bar magnets I already had and they are just a little too heavy for the fan, particularly with it running lower voltage/revolutions and I unfortunately burnt the fan out a couple of weeks ago and had to replace it. I got some of the rare earths and am going to use those going forward.

 

[kevnlis]

I have taken 2 magnets from an old dead notebook HDD. Will let you all know how it turns out.

 

[sqyre]

What your looking for are Earth Magnets...
Just do a Search on EBAY.... last time i looked there was heaps on there for cheap...
And you wont find anything smaller or stronger..

I think Jaycar may sell them too i'm not sure..??

Sqyre...

 

[chris.taylor.98]

I had a lot of problems with the HD magnets. In the end I purchased some rare earth magnets for the princely sum of 90c each.

 

[kevnlis]

I had a lot of problems with the HD magnets. In the end I purchased some rare earth magnets for the princely sum of 90c each.

Sounds great, where did you find them?

 

[chris.taylor.98]

Unfortunately was local to Melb eastern suburbs. But if you live out that way:

Alpha Magnetics

 

[Wakt]

Just beware Wakt, I went down that route with some bar magnets I already had and they are just a little too heavy for the fan, particularly with it running lower voltage/revolutions and I unfortunately burnt the fan out a couple of weeks ago and had to replace it. I got some of the rare earths and am going to use those going forward.

Actually thats a good point I didn't mention. I had 3 x 80mm fans to play with and ended up going with the one with the most torque. I also ended up using one of those power packs with the voltage regulator switch on it. This way I now have 3 speeds to choose from by regulating the voltage on the fan. There are more then 3 switch points on the power adaptor but the other voltages are either to high and the stirbar spins to fast or if at the lowest voltage I find it hasn't got enough power to start the fan up (a push with a finger is enough but its not reliable).

Either way with the 3 speeds it Works perfect!
I have used it to make over 10 starters now and have left it on overnight numerous times with no issues.

And Jaycar do sell rare earth magnets as well by the way.

 

[dan_pilbara]

Try Oatley Electronics http://secure.oatleyelectronics.com//advan...amp;x=0&y=0

Cheers

 

[dig]

Pull the magnetron from an old microwave oven and separate the magnet below the cooling fins. Compact, powerful and ring shaped, it should work really well.

 

[Aaron]

I have purchased magnets for rail guns and other projects from http://www.magnet.au.com/. Good service reasonable prices ans will sell in small quantities to consumers.

 

[ausdb]

Awesome idea, time to start scouring the verges!!

 

[kevnlis]

Right, well the notebook HDD magnets did get the bar spinning properly, but not fast enough to create a vortex. I will try JayCar on Monday and see what they have to offer.

 

[Ross]

I use a pair of these oblique magnets from Jaycar CAT. NO. LM1650.



These magnets are self centering to each other, so work great & their size gets a vortex happening even at low speed.

Cheers Ross.

 

[afromaiko]

Aussie Magnets have a good range. They are in Camberwell, Victoria and also have an online store:

http://www.aussiemagnets.com.au/home.html

I've been into their shop to pick up a few odds and ends without any hassles.

 

[Gulf Brewery]

Folks, getting slightly OT here but....

There is a limit of how fast you can move yeast without causing damage to the cell walls. While you are not likely to hit this limit of 5m/s, I have not seen any difference in getting yeast growth from slowly swirling the wort or from running the wort so that it creates a vortex.

Anyone else like to comment on this?

Cheers
Pedro