Mixer for Test Tubes

In this video I will show you how to make a mixer for test tubes. It is pretty easy and you can build it in less than 10 min.

Mixer For Test Tubes Tutorial - The funniest home videos are here

Step 1 - Get an e-Motor and Magnets

Almost any type of e-motor will work but I prefer the tiny ones which come out of a CD/DVD driver. They work at 1.5 Volts and the rotation speed is not too fast. The magnet I use on the shaft of the Motor is also from a CD/DVD-driver (you can find 2 of them close to the lens).

Step 2 - Attach the parts

First superglue one magnet to the shaft of the motor. Do not glue shaft to the housing or the unit will not work any longer.

Secondly, mount the motor to the bottom side of the rack. I used hot glue. The magnet should be close to a test tube hole. If you have a different looking rack then you have to find a place near a tube and attach it there.

Step 3 - Connect the battery

This is an easy step. Just connect the wires to a 1.5 Volts battery. The polarity does not matter. You can also put a switch in the circuit to turn the unit on and off but it is your choice.

Step 4 - Put a magnet into the tube

Put a magnet in the test tube you are about to use. I used a, 1cm (~0.4inch) in diameter and 1mm (0.04 inch) thick, neodym magnet. But you can also use one of the CD/DVD driver ones as well.

Do not use bigger and stronger magnets or the glass will crack.