I have seen a few great posts here on a DIY stirplate. Here is my take... the stir plate cost me $0.00 as I just used spare things I had lying around (the stir bar itself cost a few bucks though).
Materials
1. Computer fan: See that box sitting in front of you... grab one out of there - let's be honest, what is more important, cooling your computer components or brewing beer?
2. Magnets: Hard drives are outdated so quickly that you must have some old ones lying around (or know someone who does). Rip it open, there should be at least two magnets in there on the arms.
3. Cell phone charger: Find an old one. Look for something around 5V.
4. Cardboard
5. Twist ties
6. Tupperware
Procedure
1. Cut the plug that goes into your phone off the charger.
2. Strip the wires.
3. Attach the wires to the fan. If the fan doesn't spin, switch the wires (my fan wouldn't spin w/ the polarity reversed).
4. Poke 4 holes in your cardboard.
5. Attach your fan to the cardboard with the twist ties.
6. Put the magnets on the fan hub. Make sure both N ends are on one side, S on the other. After a drunken JB Weld accident (see picture below), I realized I didn't even need anything to hold them on, they stuck to the hub just fine on their own.
7. Put tupperware upside down over fan onto cardboard.
8. Put beaker on top of tupperware.
9. Drop in your stir bar, plug in the charger.
My magnets aren't on very straight and my stir bar makes a racket while it spins, but it does enough work to create a small whirlpool and keep my starters on the move. I also tried a 6V cell phone charger and it pushed my fan too fast and just sent the bar flying all over the place - 5V was the sweet spot for my fan.
Here are some pictures of my setup (that is JB Weld smeared all over my fan... don't ask).
http://img220.imageshack.us/img220/9007/img0591xz5.jpg
http://img220.imageshack.us/img220/2154/img0595ey9.jpg
**Disclaimer: I am not a professional - splice wires and plug into the grid at your own risk - make sure nothing is getting too hot if running this thing for awhile with a shady power supply.
Materials
1. Computer fan: See that box sitting in front of you... grab one out of there - let's be honest, what is more important, cooling your computer components or brewing beer?
2. Magnets: Hard drives are outdated so quickly that you must have some old ones lying around (or know someone who does). Rip it open, there should be at least two magnets in there on the arms.
3. Cell phone charger: Find an old one. Look for something around 5V.
4. Cardboard
5. Twist ties
6. Tupperware
Procedure
1. Cut the plug that goes into your phone off the charger.
2. Strip the wires.
3. Attach the wires to the fan. If the fan doesn't spin, switch the wires (my fan wouldn't spin w/ the polarity reversed).
4. Poke 4 holes in your cardboard.
5. Attach your fan to the cardboard with the twist ties.
6. Put the magnets on the fan hub. Make sure both N ends are on one side, S on the other. After a drunken JB Weld accident (see picture below), I realized I didn't even need anything to hold them on, they stuck to the hub just fine on their own.
7. Put tupperware upside down over fan onto cardboard.
8. Put beaker on top of tupperware.
9. Drop in your stir bar, plug in the charger.
My magnets aren't on very straight and my stir bar makes a racket while it spins, but it does enough work to create a small whirlpool and keep my starters on the move. I also tried a 6V cell phone charger and it pushed my fan too fast and just sent the bar flying all over the place - 5V was the sweet spot for my fan.
Here are some pictures of my setup (that is JB Weld smeared all over my fan... don't ask).
http://img220.imageshack.us/img220/9007/img0591xz5.jpg
http://img220.imageshack.us/img220/2154/img0595ey9.jpg
**Disclaimer: I am not a professional - splice wires and plug into the grid at your own risk - make sure nothing is getting too hot if running this thing for awhile with a shady power supply.