DIY Stir plate question

[Scuba_Steve]

I am building a DIY stir plate rather than buying a speed stir. Why? I need it for homebrewing as well, and need a larger stir bar and probably more power than a speed stir will provide.

I read somewhere that the replacement stir bars to buy for the TF-100 are 1". The sample container is only about 1 1/8" ID. Seems pretty close for comfort. Is this correct?

 

[Richard320]

Yep. 25mm X 8 mm is the standard size for the speedstir. It's got a lip that centers the vials.

 

[Bama Rambler]

There's not much room in the vial with the standard magnet. You can find magnetic stirrers for less than $70 on Amazon or EBay.

I love the speed stir, but it's not a true stirrer as it doesn't have a spinning head to rotate the bar. It uses an array of three stationary electromagnets that cycle around to cause the bar to follow.

I have an Apollo stirrer that has a rotating magnetic head that will spin a pretty large bar or cross and cause a tornado vortex in a pretty large beaker.