I looked on the web and found that even a low end stirrer runs upwards of $200 and that has very low precision and almost every stirrer I saw on the web used a PC type fan with magnets mounted to it and a speed regulator.
So, I decided to roll my own stirrer, only using solid state components and a PIC micro CPU at the core to regulate speed and generate the necessary quadrature sin wave drive.
Here's a couple snaps (pre-paint job)
With a flask (around half speed)
![Image](http://i13.photobucket.com/albums/a278/SuperSheepy/stirrer1.jpg)
Just the stirrer
![Image](http://i13.photobucket.com/albums/a278/SuperSheepy/stirrer2.jpg)
I estimate this unit would have costed around $100 to build if I only bought the components needed. Not bad I think
![Smile :)](./images/smilies/icon_smile.gif)