Introduction: Mixer for Test Tubes

Picture of Mixer for Test Tubes

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

Step 1: Get a E-Motor and Magnets

Picture of Get a E-Motor and Magnets

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

Step 2: Attach the Parts

Picture of Attach the Parts

First superglue one magnet to the shaft of the motor. Do not glue shaft to the housing else it won´t work anymore.

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 fix it there.

Step 3: Conect Battery

Picture of Conect Battery

This is a easy step. Just connect the wires to a 1.5 Volts battery the polarity do not matter.
You can also put a switch into the circuit but it is your choice.

Step 4: Put a Magnet Into the Tube

Picture of Put a Magnet Into the Tube

Put a magnet in the 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 the one out of the CD/DVD driver.
Do not use bigger and stronger magnets or the glass will crack.


uguy (author)2008-02-18

What about solutions harmful to the magnets, won't that have some effect on the chemistry in the tube?

xemetrix (author)uguy2010-02-24

I'll second that. Always read up on what you're mixing and be sure there are no hazardous interactions before you start mixing anything.

canida (author)uguy2008-02-18

You can buy small magnets coated in teflon and various non-reactive plastics.

caseythr (author)2009-10-14

It's Neodymium (Nd), not Neodym.  You can buy ball bearingsized/shaped neodymium magnets online which might mix things better andbe less likely to scratch the test tubes.

klod17 (author)2009-08-15


steed1172 (author)2009-06-25

any problems with the test tube breaking?? too strong of magnets?..(yes I'm very optimistic....mostly) thanks

iq_abyss (author)2008-06-27

where do you buy your glasswear?

Pbyrd (author)iq_abyss2008-07-27

You can get glassware and stuff like that at United Nuclear.

one-lightbulb (author)iq_abyss2008-06-28

Nowhere! I use the one out of a kids-chemical-lab.

iq_abyss (author)one-lightbulb2008-06-28

lol, but the one in your 'ible was glass (or so you said in step 4. What kind of kids set is it, I've never seen a set with real glass, allways just plastic?

mfunk (author)2008-02-19

Wow that's simple! Good job.

westfw (author)2008-02-18

This is a neat idea.
It's worth pointing out that this is a scaled-down version of a standard piece of lab equipment: The magnetic stirrer. Fancier versions have variable speed, timers, and heaters, and cost big bucks...

Weissensteinburg (author)2008-02-18

Cool. Do you have a problem catching the magnet when you're pouring the solution out?

canida (author)Weissensteinburg2008-02-18

That one's easy- you hold another magnet against the base or side to retain the magnet.

I just take another magnet and because of the magnetic attraction they stick together at the bottom. After that you can easily pouring the solution out.

Makes sense.

GorillazMiko (author)2008-02-18

Never knew it was this easy. Nice job. And the ink in water looks really cool!

About This Instructable




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