Stirplate w/ 3speed fan

I thought I would share this with you all, since I was excited to find a fan with a speed switch already on it. I found these supplies at a local electronics store, FRY's. I believe there are several of them around but I'm sure you could find these fans anywhere.

As you can see I was inspired by those using the 120mm fan as the base. I wanted something low profile cheap and sturdy. This is what I came up with.

Antec 3 speed 120mm fan
Plexiglass top for a nice wide, sturdy base, that's easy to clean.
Coupled with a 300ma Universal Ac Adapter (1.5v-12v)

This was way easier to put together than I anticipated since I was prepared to wire a potentiometer and power switch. The fan was $12.50 and the power supply was $9.99. I works great and would even work with a regular 5-7v DC adaptor. The Universal adaptor is pretty cool, I can run the fan well slower than I would ever need to fast enough to move a gallon jug easy. With this setup I have over 12 working speeds and all the wiring I had to do was splice wires from adapter to the fan.

Just thought I would share this since I am very happy with the outcome and the price.

Do you have a picture? Also, what are the three speeds?

Pics up! The speeds on the fan at 12v are 1200rpm, 1600rmp, 2000rpm. Obviously at the lower voltages it goes alot slower. Im not sure if you can calculate the speed from that but you can easily make a close guess. If you have a ~7v converter that voltage seems about perfect. Then you have a 3 speed stirplate for 12.50.

Also you can see the switch attached to the fan (right side of pic). Its just a simple 3 way low, med, high.

Where did you get the magnet?

How did you wire power adapter to fan. Fan has 3 leads and power adapter two?

jlajr2483 said:

Where did you get the magnet?

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Sorry, I didn't notice the questions. Anyhow, the magnet is off of a old PC Hard drive. Which works out well with the 1" stir bar and you get two magnets with each drive so you can have a "keeper magnet" so you don't pitch your stir bar. The magnets are very strong, in fact I had to move my base away from the magnets slightly because they seemed to pull on the stir bar too much.

pfi309 said:

How did you wire power adapter to fan. Fan has 3 leads and power adapter two?

Click to expand...

The three leads went to a plastic clip/adapter which had only two leads. This comes with the fan, so i only spliced from those two wires. I just left the clip inline so if I ever want to unclip it for storage or use the DC adapter on another plate i can do so very easily.

I also bought one of these off amazon in the 120mm for another stir plate.
https://www.homebrewtalk.com/f11/building-stir-plate-check-out-usb-adjustable-computer-fan-253254/

It is a little more expensive but it has an awesome looking knob which I plan on mounting on the edge of my plexi. I will let you know how it comes out and what voltages I used.

Sweet looking setup, I used to live in SD and love Frys. That is a computer superstore! I'm currently making a stir plate and am having a hard time getting my bar to stir properly, did you center your magnet on the fan?

It took me a little while but I centered it. I actually used spray adhesive on the magnet, let it dry, then centered it and adjusted it. The spray adhesive actually works really well and will let you move it ever so slightly or even peel it off and re-stick. It has held up well and the magnet hasn't moved at all.

How big is your bar? Mine is 1" I think, it works well and I think i could go up to 1.5 or so, but not bigger. If its not centered properly it will run a little rough and make more noise. If its real bad it will throw the bar.

I was going to post that you need more space under the fan to pull air and then realized that we're not after air movement...just spinning the bar.