Monday, December 29, 2014

Magnetic Stirrer

My latest adventure with metal working, and magnets is the Magnetic Stirrer.  A friend at work gave me the idea, and it seemed like good application for the spare sheet metal, and magnets out in the garage.  The rotor is 1/8" aluminum sheet cut to 2.5" diameter.  I used a 1/4" inside diameter Arbor to mount the rotor on the motors shaft.  I had a little trouble with that because the motor shaft is 1/5", so I used a 1/4" outside diameter aluminum tubing, then bored the inside out to 1/5".  The set screw on the Arbor provides a crush fit to make the Arbor stay on the shaft.
There are two, 10 pound Neodymium Magnets, facing opposite directions, which will latch on to the Stir Bar inside the Erlenmeyer Flask on top of the Magnetic Stirrer.  The plan is to have a piece of Plexiglass sit just above the rotor, and the Erlenmeyer Flask will sit on top of the Plexiglass.  Next in the process is to fabricate the base support for the motor, and Plexiglass top, then to assemble the Pulse Width Modulation Voltage Regulator which will act as a Speed Control.