My shamelessly cheap $12 DIY stir plate

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I did the same thing, but I put this fan inside a wood cigar box, which was $5 a local cigar shop, but you might be able to get one for free. I drilled some holes in the box and used the screws that come with this fan to attach it to the lid. I bought neodymium magnets from K&J Magnetics. At some point I'm going to clean it up and mount the speed control knob properly.

stirplate1_zpsf36c7d47.jpg
 
Good option for people who dont have access to a soldering iron or any of the other necessary parts.
 
I have a 0.4 Amp fan in my box, it only whirlpools. Is this too strong of a fan? Is bad for my starter if it goes this fast?

image-2978732815.jpg
 
KurtB - the smaller one seems to have a higher RPM range than the larger one (1300-3000 vs 800-1500), so I'm not sure why you would need it. I have the smaller one and I have to keep it on a low-medium setting or it will throw my stir bar, which is 1.575" long.

I also have one of these in my keezer. It reduces condensation and the frequency of the compressor coming on. The flat cord is nice too, because I can close the door on it and did not need to put a hole in the keezer to run it through.
 
Thanks for the info. I was thinking about sticking a fan into my keezer and did not even think about using one of these. Great idea.
 
Thanks for the inspiration CS223 & redshift76. It cost me $13.76 for the fan via the Amazon link, $2.99 for the 10 pack of magnets and $3.00 for the USB plug in adapter. Not as cheap as some, but not bad!

stir plate parts.JPG


stir plate.JPG
 
I love the use of tupperware on these. I might do that as well. Just go get some cheap, sturdy tupper ware and do that. I do like the look of a cigar box though. Otherwise I'll find something. I always do. The fan itself can be made into a stand but I don't know about there being much grip on the grille to keep the flask from vibrating off. Def don't want that.
 
built this over the weekend (Friday). Used the Thermaltake 12, which is larger, just in case I wanted to do 3-5L starters (currently doing 1 and 2L). I mounted the fan to a piece of 1/2" MDF with a 2" hole drilled in the center, then slid a 2x4 under either side of the MDF to slightly elevate it/support it. I glued a zinc washer to the fan's center and just stacked 3 neodymium magnets to either side (6 total), didn't glue them down. Using a 1.5" stir-bar but had issues with throwing in a large pickle jar (my 2L, well, 2.36L "flask") due to non-flat bottom, even at lowest speed. So I put dip-tube o-rings on either end of the stir bar (it has the fulcrum in the center) and ran it just slight above lowest speed on a 2L starter beginning Saturday night. Wasn't a big vortex but I had good krausen and in about 18 hours it fell. I let it go and pitched Sunday around 3PM, so just under 24 hours since it was on the starter. Worked well for about $35 total, including fan, washer, magnets and stir-bar.

q27jh.jpg
 
So i built one and it works. Only cost was the stir bar.
Lucked out with the box i chose (thickness of lid/space between magnet and the lid) and the strength of the hard drive magnet, because it spins in liquid without a speed control (or an on/off switch).

Here is my question:
How do I use it?

I boiled about 1ltr of water, added 3/4 cup DME, boiled another ten to fifteen mins, left it covered, let it cool

When it was cool, i opened my yeast--white labs 007, shook it until mixed, and dumped it into the glass vessel on the stir plate. Fired it up and got a nice cyclone in the middle. Left it running for about 5 hours.

Still no signs of life. Didnt have another vial so i got nervous and pitched it on my freshly brewed and aerrated wort.

Im reasonably confident it will kick off by morning but im also sure my "starter" did much more than increase my chances of an infection.

...sigh...maybe i shouldnt have experimented until i was more sure of the process...just got excited about using the new DIY homebrew gadget.. :)
 
my starter took about 18 hours to show krausen. leave it be, it should be fine
 
NewBrewB said:
So i built one and it works. Only cost was the stir bar.
Lucked out with the box i chose (thickness of lid/space between magnet and the lid) and the strength of the hard drive magnet, because it spins in liquid without a speed control (or an on/off switch).

Here is my question:
How do I use it?

I boiled about 1ltr of water, added 3/4 cup DME, boiled another ten to fifteen mins, left it covered, let it cool

When it was cool, i opened my yeast--white labs 007, shook it until mixed, and dumped it into the glass vessel on the stir plate. Fired it up and got a nice cyclone in the middle. Left it running for about 5 hours.

Still no signs of life. Didnt have another vial so i got nervous and pitched it on my freshly brewed and aerrated wort.

Im reasonably confident it will kick off by morning but im also sure my "starter" did much more than increase my chances of an infection.

...sigh...maybe i shouldnt have experimented until i was more sure of the process...just got excited about using the new DIY homebrew gadget.. :)
Click to expand...

To make a starter, an ideal ratio of water to DME is 10g DME for every 100mL water. Brewers yeast on a stir plate should be left for at least 24 hours to allow sufficient cell growth. You won't see much activity (if any) after just 5 hours. Make sure there's some sort of cover over your glass vessel. Sanitized Aluminum foil works great. It can be easily secured over the top, but still allow sufficient airflow to help the yeast growing. Just an FYI, don't put an airlock on your starters. :)
 
Fermentation kicked off just fine, so just like 90% of the posts on here, I was worried about nothing.

Thanks for the 24 hr timeframe estimate. I will plan my next brew day much better and try to pitch at the height of the starter activity, after a day's worth of dizzy spinning yeasties.
 
I can't get my stir stick to stick to the magnets on the fan... Are they just not strong enough magnets ya think? I have tried two different sets...one I got to stay for around 2 minutes or so but slowly but surely it comes off and I can't turn it up full blast without it coming off. Stronger magnets? I have a washer between the magnets like the OP says also...
 
Matteo57 said:
I can't get my stir stick to stick to the magnets on the fan... Are they just not strong enough magnets ya think? I have tried two different sets...one I got to stay for around 2 minutes or so but slowly but surely it comes off and I can't turn it up full blast without it coming off. Stronger magnets? I have a washer between the magnets like the OP says also...
Click to expand...

run it slow. no need to run it fast. ican't get mine to run fast either, but no problem, just keep yeast in suspension
 
redshift76 said:
Same fan/controller mounted in a plastic container. Super easy.
Click to expand...

That is a great solution. My starters have, more than once, tried to escape. A bead of silicon on the washers would be my choice.
 
Matteo57 said:
I can't get my stir stick to stick to the magnets on the fan... Are they just not strong enough magnets ya think? I have tried two different sets...one I got to stay for around 2 minutes or so but slowly but surely it comes off and I can't turn it up full blast without it coming off. Stronger magnets? I have a washer between the magnets like the OP says also...
Click to expand...

Do you have the poles configured correctly? You need one stack of magnets with the N pole up and the other with the S pole up.

If you have your magnets stacked like this all stuck to one another: <<<<<<
pull the stack apart in the middle and stick them to the washer like so: \/ /\
 
Rigged one of these up on Friday and it works great on the lowest speed but tends to throw a 1.5" bar in a 2L flask.

No biggie- it still does its purpose just fine for under $20!


Thanks OP!
 
To everyone having issues with throwing the bar:

Try putting dip-tube o-rings on both sides of the bar, then try again. It worked for me, interested to know if it helps anyone else.
 
tre9er said:
To everyone having issues with throwing the bar:

Try putting dip-tube o-rings on both sides of the bar, then try again. It worked for me, interested to know if it helps anyone else.
Click to expand...

Interesting ... Will be trying that this week end when I get home!
 
tre9er said:
Try putting dip-tube o-rings on both sides of the bar, then try again. It worked for me, interested to know if it helps anyone else.
Click to expand...
I use two O rings too. My stir bar has a raised ridge in the center and it
immediately threw it. I put an O ring on either side and haven't had a problem since.
 
Just an FYI: I noticed that if you disconnect the speed control unit from the fan, it will run slower. That may be helpful for smaller starters.
 
After reading this thread last week, I immediately went to Amazon and purchased the Thermaltake usb fan unit and I couldn't be happier. :D

I completely removed the fan shroud and the speed control knob. The fan was attached to the base of the box using double sided sticky tape. I used the box that my RAZR Maxx came in for the case. I punched a hole in the box for the speed control knob to stick through and just used a bit of crazy glue on the back side to hold everything in place. I punched another hole out the back for the power cable.


2012-12-09_14-41-57_580.jpg


The washer the hard drive magnet is attached to is held to the fan by double sided sticky tape. I used it with a 1" stir bar to whip up my last 1L batch of starter and it worked great!


Even on low, this DYI stir plate has no problem creating a vortex.

2012-12-09_14-46-52_108.jpg


Thanks for the tip!
:ban:

Don
 
My stir bar is rolling rather than spinning. I'm using one magnet from a hard drive and a 2" stir bar that I grabbed from the lab at work. Think the stir bar is too big? It does have a rib in the middle. It rolls around then throws the bar. Any thoughts? I'll see if they have a smaller bar tomorrow.
 
ObiDon said:
Have you tried adjusting the distance between the magnet and the stir bar? I had to muck about with mine for a bit before I got it just right.

Don
Click to expand...

Yeah, try adjusting the distance with shims under the flask first, to increase it, and run the fan on the slowest speed. If more distance isn't the answer, perhaps it's less.
 
apshaffer said:
My stir bar is rolling rather than spinning. I'm using one magnet from a hard drive and a 2" stir bar that I grabbed from the lab at work. Think the stir bar is too big? It does have a rib in the middle. It rolls around then throws the bar. Any thoughts? I'll see if they have a smaller bar tomorrow.
Click to expand...

If you have another HD magnet, try putting it on top of the one you already have on the fan. This worked wonders for me. I don't know if it was the increased magnetic field or the reduction in distance between the bar and the magnet, or both. Either way, I don't through my bar anymore. :ban:
 
I figured it out. I wasn't letting the magnet and the stir bar align before turning on the fan. I also grabbed a smaller stir bar which works much better.
 

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