My $2.66 DIY Stir Plate...

[MadCnty]

Hello all first time poster, long time lurker...
I just wanted to post this DYI project as it is very easy to do, and yes I know there a ton of video tutorials on how to do this, but I just wanted to show my finished product...
First off the only thing I had to purchase was the cigar box which I got at a local store in the Indy area... I paid $2.49 + tax for a whopping total of you guessed it $2.66...
The rest of the items I already had "around the house"... I used an old 120mm computer fan, the magnet from an old hard drive, an old Zalman Fanmate (for speed control), misc. hardware, and an old 12V adapter... Here it is...

 

[twistr25]

The key is certainly having all of that around the house. Well done though!

 

[pilgrimhd]

So I've been lurking around here for a while, too, and I have also been drooling over the $99 stir plates I see in all the shiny catalogs. Sure beats getting up and swirling the flask every hour. Well, after reading many posts and watching a few videos, I decided to scrounge my "spare parts" (read: junk my wife wants me to throw away). I came up with the following:

- 12v 3 mA AC-to-DC adapter
- 120mm PC case fan
- Neodymium Magnets
- Wooden Cigar box

So I wired it up and realized that at 12 volts, the fan motor spins out the stir bar before I got a good whirlpool going. I needed a slow start. So how do you regulate the speed of a DC fan? With a voltage regulator.

Having started my Marine Corps Career as a RADAR technician, electronics are not new to me, so I logged into my mouser.com account and put together a parts list:

- LM317 voltage regulator
- 150 ohm 1/2 watt resister
- 2K ohm potentiometer
- .1 uf capacitor (100 volt)

Simple circuit with the pot providing adjustment voltage and the 150 K ohm providing output load. Range of voltage is 1.2v to 11.1 volts, plenty of adjustment to slowly speed up the stir bar to a good whirlpool.

If anyone is interested in the schematic, I can sketch something up.

Harry Pilgrim
Fredericksburg, VA