Cigar Box Stir Plate

OK, so get your self a cigar box (or anything big enough), a computer fan (12 volt), two rare-earth magnets from a hard drive (EDIT: I used only one later), and a model train controller (anything that controls the 12v DC voltage). The hard drive in the computer is a great place to find these magnets and there are usually two. Just open the drive and be careful when removing the magnets as you can break one like I did.


I found a button that spaced the magnets far enough apart to allow me to glue them to the fan. I made sure the magnets were polarized correctly and then used wood glue (only glue I had around).


After gluing up the magnets I cut my cigar box to allow the controls to stick through. I used a dremel cutoff wheel so it burned the wood a little, but smelled good, lol.


I glued the train controller to the inside of the box and then let dry. Finally, I mounted the fan and wired it to complete the project. I mounted with drywall screws using pipe covers as washers and spacers. I cut off the screw ends with the dremel.


And that is all it took to make my stir plate. Now to buy a stir bar. Here is a better picture of the mounts.

Nice job. I've got the box, fan, power cord, and magnets but lack the speed controller for the computer fan. Show a picture of the box.

Wild

Here are better pictures of the box.

THAT IS WHAT I'M TALKIN ABOUT!!!!!!!!! SWEET setup man! Anyone know where to score a cigar box?

Grimsawyer said:

Anyone know where to score a cigar box?

Click to expand...

A cigar shop?

If you have any of those big crafts stores in your town (Michael's, Hobby Lobby, etc...), they have all kinds of small wooden boxes like that that you can buy.

But..... nothing beats the smell of all that red cedar smoke in your face while you're grinding away with a sand cutting wheel. LOL

Grimsawyer said:

THAT IS WHAT I'M TALKIN ABOUT!!!!!!!!! SWEET setup man! Anyone know where to score a cigar box?

Click to expand...

I just built something similar last week. The cigar shop near here sells used cigar boxes of all sizes for $2.

Is the amperage of the fan an issue? I was able to find a 12v fan, and a 12v power supply, but the amperage didn't match. The fan was 550mA and the power supply 350mA. I hope not, as I'm able to get both for less than five bucks.

ModlrMike said:

Is the amperage of the fan an issue? I was able to find a 12v fan, and a 12v power supply, but the amperage didn't match. The fan was 550mA and the power supply 350mA. I hope not, as I'm able to get both for less than five bucks.

Click to expand...

That supply wont last long... It will run hot and eventually fail. Find a power supply that provides at least the required current demand of the fan you'll be using.

figures, my stirplate is done in the cigar box and the fan controller blew out on me as soon as I was ready to use it. I'm still trying to figure out why it throws my stir rod at low speeds......I guess it's the concaveness of the flask, which pisses me off

Bottom line, great job on yours buddy!

JoeRags said:

That supply wont last long... It will run hot and eventually fail. Find a power supply that provides at least the required current demand of the fan you'll be using.

Click to expand...

So if the power supply has a higher amperage than the fan, things should be OK?

Update!!!!!
Ok, so I changed it up a little. The two magnets just weren't working. I removed one and placed the other one in the center of the fan and re-glued. Works like a charm, only even at the lowest setting I am spinning the stir bar too fast. I am going to get some different Ohm resistors and try that out until I get the slowest speed I need, and then I should have it set perfect.

wortmonger said:

Works like a charm, only even at the lowest setting I am spinning the stir bar too fast. I am going to get some different Ohm resistors and try that out until I get the slowest speed I need, and then I should have it set perfect.

Click to expand...

Just a thought;
If you placed some sort of divider between the bottom of the stirplate and the glass jar so that there is less magnetism rotating the stir bar might be a simpler option?

Cheers
BeerCanuck

You may be right!!! I have it spaced from the bottom of the box with those blue spacers, but if I had something like a thin leather coaster to go under the yeast container it may slow down the bar. I have to go try this right now, lol. Thanks for making me think.

Tried it out with a mason jar and 2 sheets of paper folded over to make 8 sheets thickness. I tried more and the bar keeps getting flung off, but the RPMs are still too fast on the lowest setting of my controller. I think I will have to go with the resistors, and they are cheap and easy enough to connect with butt-connectors to my power wires to the fan.

I know this is kinda old but if you were to put a resister on there that you could change, I don't remember what they are called (like on a stereo volume knob) that way you could dial in how much speed you want.

Edit: I remember, Potomeiter (not sure of the spelling though)

Here's one I built with a friend. Used a cohiba box, a PC fan, a hard drive magnet, some LEDs and a radioshack voltage regulating plug. Oh yeah, we pimped it out with those LEDs and a plexiglass top. All in all though I think it actually cost us about $25 to make. $19 of which was the Radioshack plug...

WortMonger said:

Tried it out with a mason jar and 2 sheets of paper folded over to make 8 sheets thickness. I tried more and the bar keeps getting flung off, but the RPMs are still too fast on the lowest setting of my controller. I think I will have to go with the resistors, and they are cheap and easy enough to connect with butt-connectors to my power wires to the fan.

Click to expand...

You definetly don't want to increase the gap between your stir bar and the magnet. You'll reduce the magnetic hold on the stirbar and it will be MORE prone to flying off. With ours the magnet is nearly flush with the plexiglass top. Also, take extra, extra care to be certain that magnet is centered. Otherwise your stir bar will actually try to spin in an ellipse which will throw it off. Finally, have you tried the cross-bar style stir bar? That seemed to work much better for us...HTH

Grimsawyer said:

Anyone know where to score a cigar box?

Click to expand...

Did you really ask that?
It's ok! I like beer too!

So I'm working on a stirplate myself. I have a 12vdc fan, but only a 15vdc and a 9vdc transformer. I'm not sure if the 9v spins it fast enough. The 15v definitely does, but will it burn out the motor prematurely? (I don't like the idea of buying one of those crappy radio shack ones for $20)

Thanks in advance!

So, I am in on the stir plate build also. I actually went the hard way and created a voltage regulator ( needed one for another project too).

I have a question about the magnets. I ripped one (yes, only had one ) out of an old hard drive.
Do I need two? Can I cut this in half?

You don't need two, just make sure you "center" it as best you can. I put quotes because it is an irregular object and you just need it to pick up enough of the stir-bar to turn it without throwing it off center in your yeast vessel. When I did this I used the magnetic force inside the fan to be sort of a guide. You can feel when you get a little too off and it just feels right when you are in the right position. Then secure it to the fan and then you are ready to place the assembly wherever you are going to have it in your enclosure/fabrication. It is important to remember the right side of the fan, lol. You need it on the side that moves. I almost didn't do this my first time, so I was glad when I had the epiphany of a moment in intelligent clarity, lol. I needed coffee like a junky needed his smack that day.