Stir Plate - $Free.99

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 Magnets: Hard drives are outdated so quickly that you must have some old ones lying around (or know someone who does).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.

That's great

OMG you rock

I love it.

I personally want a nob to control speed, but that is an unneeded feature that increases the price by, um, infinity, over free.

I do like the gladware project box though.

Well done!

Ghetto??? How bout ghetto-fabulous. I love it. I didn't think about the 5V charger, but after making mine I would have rather had something much lighter like yours. Might have to build another one (in a cigar box though ).

I just finished my cigar box stir plate today. The very moment that I finished I saw ways to improve the next model.

My stir plate totaled around $10 for the potentiometer (speed control), on/off switch, and some nuts, blots, and washers. The cigar box was free, I already had wires, an IT guy from work harvested a bunch of magnets from hard drives for me, and I already had a fan.

I can't wait for my stir bar!

yup, that's ghetto. Good stuff just the same. Bravo!
thanks

Good Job!!!

If you can get your hands on variable voltage transformer you can use it to speed up and slow down the fan.

I'm using a similar set-up the this style of transformer. I can regularate speed to some degree.

BeerStone said:

**Disclaimer: I am not a professional -

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Time to break out a classic....

That is straight up ghetto to the max. But it works, so that's cool.

Thanks, I just made one of these my self.

Does the size of the whirlpool matter?

I get a whirlpool at the top of my 1 Liter flask when filled, but it only goes down about half an inch. I figure it wouldn't matter too much since the important thing is exchanging CO2 with oxygen, but all the stir plate pictures I've seen have a vortex that goes halfway through the flask.

slyngshot said:

I can't wait for my stir bar!

Click to expand...

You can always just use one of the magnets from the hard drive as the stir bar.

I just built a stirrer and used one of the magnets from the hard drive on the hub of the fan and the other as a stir bar. I forced the magnet into some vinyl tubing, cut each end so it was a 1/8 of an inch or so longer than the ends of the magnet, melted the end a bit with a lighter, then pinched it shut with needle nose pliers. It is a perfect match to the magnet on the hub and it sticks great. I can spin 3/4 of a gallon with the vortex all the way down to the stir bar and it won't get thrown.

wow im going to do this!

The turbulence created by the the vortex hitting the bottom of your starter is what rapidly dissolves oxygen. Have you considered the effects of not balancing the magnets on the fan to achieve less wobble? Nice job on the ghetto fabulous plate!

Nice work!

Looks like I'll be hitting Radio Shack on the way home tonight. How did I miss this thread?

I have three of these, exactly the same, except I have no cardboard, and just put the starter jug directly on the fans because on these little rubber things (pieces of a wrench handle cover) on the corners to minimize vibration, but they hold the starter. I found that 4.5v works best for me, and I have a TON of those little adapters laying around.


Also, magnetic aquarium scrubbers have REALLY strong magnets in them also.

I just made one of these also. I made the mistake of buying a 2" stir bar that I think was causing me all kinds of problems. If the magnets are not longer than the stir bar there is good chance it will not center over the magnet and get thrown. I had to butt two magnets together so they are actaully longer than the stir bar to get it to center (I also stacked 2 magnets for a total of 4).

I wanted to go completely ghetto so I was trying to use a jar or container I had around the house. The shape of the jar bottom makes a big difference. I tried growlers, juice jars, you name it. I finally dug up an old french press that's about 1.5L and it works. It's smooth and flat.

I also had to play around with the distance between the magnets and the stir bar. Too close and the magnetic force keeps the fan from spinning. Too far and it won't hold the magnet at high speeds.

I'm probably going to eventually buy a 3L flask and 1" stir bar. In the end it would have been way quicker to buy the parts and put one together or even buy a stir plate - but that's not the point now is it?

i love free stuff ! im making one of these !!

I like the directly on the fan approach. I made mine inside of a plastic box, similar to Tupperware or something, and after a few uses the top bends down under load and stops the magnet from spinning. I think I'll look at removing the box entirely.

Where do you buy the stir bar and what size is recommended? Thanks.

PJM said:

Where do you buy the stir bar and what size is recommended? Thanks.

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Google Stir Bar - lots of sources. Here's one from Rebel Brewer - most folks swear by the 1" size. Too long, and it will throw. All you need to do is get it spinning, no need for huge vortex.

oh, and PJM - WELCOME to HBT!

Can I just use a blender? I feel like that must be too simple and I must be overlooking something.

mintyfresh12 said:

Can I just use a blender? I feel like that must be too simple and I must be overlooking something.

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too much speed, it would shear the yeast and put it under too much pressure IMO.

if anyone is making a starter with a blender, please share pics

PJM said:

Where do you buy the stir bar and what size is recommended? Thanks.

Click to expand...

I bought mine from www.stirstarters.com. He has good prices and great customer service. He advertises on HBT to boot.

mintyfresh12 said:

Can I just use a blender? I feel like that must be too simple and I must be overlooking something.

Click to expand...

1. No way to sanitize the blender container thingy.
2. Not designed to run continuously. Probably would not last long and may overheat.
3. Would be noisy as hell.
4. Would scare the bee-jesus out of the yeast for sure.

Wow. I'm blown away. I was going down the list of materials and was like, I have that, I have that, I have that.... I have it all right now! I'm building one this weekend. Thanks! Can't wait till I make that next brew!

barrooze said:

Wow. I'm blown away. I was going down the list of materials and was like, I have that, I have that, I have that.... I have it all right now! I'm building one this weekend. Thanks! Can't wait till I make that next brew!

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Agreed! I knew I kept all of those old file servers and hard drives for something!

Now I can make happy yeast starters. Great posts are for all time.

Sorry to resurrect this thread but this is my first post and I guess I'm not allowed to start a new thread yet.
I am thinking about making a stir plate. Has anyone used this fan?
AC Infinity AI-MPF80A Quiet 80mm USB Fan for Receiver DVR Playstation Xbox Computer Cabinet Cooling https://www.amazon.com/dp/B00G059G86/?tag=skimlinks_replacement-20
I was thinking it would be good and cheap. Maybe add a potentiometer and wouldn't need a box

You may have seen this one but i would recommend using the fan shon in it. It has a speed dial already built in. I followed the write up and mine works great!https://www.homebrewtalk.com/showthread.php?t=338695

Yeah I did. I was looking for that fan when I found this other one. I was thinking it'll save me money if I didn't need a project box. I guess that one is better because it comes with speed control though

I didn't end up using a project box, I used the grate that came with it. I switched the screws for longer ones and used screw caps to enen it out and keep it from sliding. In total I spent about 20.

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Oh ok. Well dont laptops have fans in them? Couldn't I take the fan out of an old laptop that I'm not using and use it?

That could work. I'm not intimately familiar with the inner workings of laptops. You would need to adapt a power source and diy some hardware for it to work. Maybe someone with more knowledge could fill you in.

So I ended up sourcing a fan from my father in law for free! I bought a potentiometer at radio shack and a switch then bought some gorilla glue. So in all I spent less than 10$ if you include the glue that I barely used. I do need to get an enclosure for it but It worked fine for both my starters last weekend.

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