My DIY yeast stir plate

[Happywanderer]

So, I got tired of shaking my starter. Call me lazy.

So I made this



80mm or 120mm cpu fan (if you don't have a spare, ask around...IT Departments usually have spares).
4 screws and nylon nuts ... #8 size
1 switch (LED ... Sooo pretty)
1 rheostat (25-ohm is what radio shack had in stock)
Spare wire
Soldering iron
1 pack of rare earth magnets - small (1/2" by 1/8" or something similar in size). Homedepot AND Ace carry these now. They come in packs of six or more. So you can make multiple stir plates!

And a cigar box. Just go down to your local tobacco shop, buy a cigar or some pipe tobacco and ask nice...should be free. This was a nicer wooden box I got for free for buying a pipe.

Then sit back and enjoy a cold one as your yeast stirs itself.


Hopefully this gives you inspiration. Really easy DIY. even for lazy me.


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[Natdavis777]

Looks good. Mine aren't as easy on the eyes, but they get the job done. Both are chugging away as we speak.


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[impossiblescissors]

What are you using for an AC-DC adapter? I've seen other stir plates use a cell phone charger or generic 6V adapter with the connector cut off. It'll be interesting to see what voltage you're putting across the fan and what speeds you're getting.

My current stir plate uses a Dynex AC adapter with six interchangeable plugs and selectable voltage. Radio Shack had the correct coaxial power jack for the back (Type M or N will work with the Dynex adapter.) That's a much pricier approach compared to the clipped 6V adapter!

For my next stir plate I'm kicking around the idea of using a male USB Type A cable for power, since USB wall chargers are pretty widely-used these days. The 5V from a USB port should be enough to spin the fan up to a decent speed. I suspect the fan can be as small as 40 mm (scavenged from a Wii cooler) and still get adequate torque on the magnets and stir bar.

 

[Happywanderer]

I went with a spare 12v charger I had lying about. I haven't wired in a quick disconnect for the back yet, but it's on my list of eventual improvements.

I haven't measured voltages and RPMs. But I can say it gets going very nicely indeed. I'll take some readings and post them tomorrow.

Actually I can't measure RPMs ... Don't have an o-scope. And I can't recall what the max RPM on this fan is at 12v. 1200 maybe but that is a guess. Standard 80mm CPU fan I ripped out of an old dell.



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