The goal was cheap and easy. I made it from items already around the house.
Used a 3v cell charger, CPU fan, hard drive and a plastic bowl. The only tool I used was a razor blade to cut and strip the wires from the cell charger. Since everything was repurposed the cost was zero, except for the flask and stir bar of course.
The hard drive is only there to raise the fan. No switch or speed control. 3v seems to be perfect. I spent the most time figuring out the trick to get the stir bar in the middle of the flask.
Used a 3v cell charger, CPU fan, hard drive and a plastic bowl. The only tool I used was a razor blade to cut and strip the wires from the cell charger. Since everything was repurposed the cost was zero, except for the flask and stir bar of course.
The hard drive is only there to raise the fan. No switch or speed control. 3v seems to be perfect. I spent the most time figuring out the trick to get the stir bar in the middle of the flask.