A quick "IT Guy" Super-Starter DIY stir plate

Hey guys! I'm new here and I love DIY, so figured I would contribute a little something. I know there are tons of DIY stir plates, but I made this one on my lunch break from crap I had laying around the house. Yes I know, not everyone is going to have optical termination shelves laying around their house, but I'm hoping this might spark ideas for other people on how easy it is to make a great stir plate that will last a long time! I spent about 40 minutes total.

- 13 washers (12 for the corners, 1 for the center of fan's magnet)
- Plexiglass/glass/plastic etc... (I used a scrapped fiber termshelf cover)
- 4 10-32 screws, 1 self-tapping screw to create holes
- AC powered IT cabinet fan
- Hard drive magnet on the center washer, which is apoxied/glued to the center of the fan

Since I want this stir plate to handle 2L starters AND last a long time, I want to be sure and use a fan that is very powerful - that is why I opted for an AC powered cabinet fan. Why you might ask? In my profession, I see DC fans bite the dust all the time, but I've never seen one of these AC fans take a dirt nap. They run 24/7 and are powerful enough to sufficiently cool very important equipment. If you see a scrapped/decom'd closed rack, these are typically in the top - a great score from scrap! The only issue is speed control, which I will get to in a moment, but let's get to the build!

Again, this is a work in progress, and I just did this on my lunch break today in about 40 minutes.

This is the info on the fan:


Here is the rough build:


After talking to my electrical engineer buddy, the only way you would want to control speed on an AC fan would be to do the PWM trick, or you would actually have to spec out the fan and build a controller yourself.

Fortunately, we don't have to!

Here is the manual speed control for this style of AC fan (and any AC fan on this site):


I just ordered it here: http://www.coolerguys.com/840556089346.html for about $17 shipped, and I'll update this thread when I get it in.

The stir plate DOES spin my 2" stir bar with no liquid in it, but once the stir bar tries fighting the resistance of the liquid, it cannot keep up with the hard drive magnet without having speed control. I'll let you guys know how it goes!

Nice work so far looking forward to the finished product.

It's working like a champ! I will say that the dial I ordered definitely DOES work with this fan, but it doesn't work perfectly. The only problem is it doesn't actually kick on untill you reach about 60% power on the dial. I also just leave it at the absolute lowest setting, and the stir bar has no problems getting the 2L starter to this state:







I would say if there is one problem with this build, it's that the fan is too powerful! But then again, I'm using parts that were laying around and buying a new fan would be counter-intuitive to the DIY mantra I'm very happy with this quick build!

I want to post an update here about this stir plate. It is FANTASTIC! I am doing my first 10gal batch this weekend, so I resurrected some dry ale yeast from my frozen yeast bank. I am on stage 2 of my 3 stage 2L yeast starter for this weekend, and it's looking great! That 2" stir bar is doing WORK!

I just added another round of dme/water to it.

Youtube link:

8 Hours later:

3of3, 12 hrs after first video

Just racked to secondary, and after 7 days in primary we've attenuated from 1.045 --> 1.009. My original 5gal batch of this was 1.050 -->1.010. This was my first 10gal batch, so I'm very happy with the numbers. Resurrecting only 1 vial of frozen ale yeast from my yeast bank and using this DIY stir plate with 3 stages definitely did the trick! Love it!