The Twins are born!

[backyard brewer]

Twin stir plates that is... I used the LM317 circuit for control and they work very well. I test drove them tonight with a 2L flask and 1" bar. I can draw a whirlpool down very easily. I used a Rubbermaid food-type container for a housing to make them more or less water resistant. It works better than I thought, I was worried about the flex but it holds the 2L flask with no trouble at all. The only complaint I have is that I can only use about the first 1/4 turn of the speed control before it will throw the bar. A little more control would be nice, but even at that it'll draw down the maelstrom and hold it without throwing the bar, so that's fine. I'll play with a different resistor and maybe a different pot to see if I can increase the adjustment range.

A Descent Into The Maelstrom:



The fan and magnet:



The LM317 speed control: