My Stirplate... Cheap and Easy Build...

[Mojzis]

I'm not getting a variation in speed. I've got it wired the same as this build, I'm using the same pot as this build, and I have a 12v supply. I've also tried running the ground from the fan straight to the supply. Same problem and my LED on the switch doesn't work. Any ideas as to what I'm doing wrong? I think I've tried every possible way of wiring it.

Edit: I checked the output at the pot. On low I've got 10.2v on high I've got 12.1. Is this not enough to notice a change in speed? Do I need a smaller supply?

I had the same issue with the 12v supply. Go smaller and it will work. I used a larger fan and a smaller supply and it is perfect now.

 

[dchd1130]

I had the same issue with the 12v supply. Go smaller and it will work. I used a larger fan and a smaller supply and it is perfect now.

Ok, I will give that a try.

 

[rideincircles]

Subscribing for my to do list once I find an old computer.

 

[Newsman]

Subscribing for my to do list once I find an old computer.

Heck, just go down to Harbor Freight (if you have one close by or somewhere else if you don't) and pick up a package of "rare earth magnets." They'll work just fine!

 

[dchd1130]

Ok, I will give that a try.

No luck. I tried a 5v supply. Still not a noticeable variation in speed. 5v is a little weak. It had a hard time starting the fan. Is it possibly a problem with my fan?

 

[Mojzis]

No luck. I tried a 5v supply. Still not a noticeable variation in speed. 5v is a little weak. It had a hard time starting the fan. Is it possibly a problem with my fan?

I doubt it. You have the pot wired correctly? 5v probably won't be good enough. I'm using a 9v I believe.

 

[dchd1130]

I doubt it. You have the pot wired correctly? 5v probably won't be good enough. I'm using a 9v I believe.

Yes, supply goes in the center post and out one of the side posts. With the 5v supply I get a range of 4.1 to 5.1v. Thats a 20% change vs the 10.2 to 12.1 is only a 16% change. So Im gonna guess that with a 9v supply Im going to go from 9v to 7.5v. Is there a way to get a wider range? I would think a 30% variance would be a lot better. It just seems like your not going to see much of a change in speed with sub 20% changes. Like I said I cant visually see any change.

 

[LovesIPA]

I used a 6V supply and I can barely turn it on before it throws the bar. 12V is too much IMO.

 

[dchd1130]

Ok, I found an adjustable supply. Its 300ma vs the other was 12v 800ma. I can turn this one all the way up to 12 or back it down to 6. Between that and the pot Ive got plenty of adjustment.

 

[Mojzis]

Ok, I found an adjustable supply. Its 300ma vs the other was 12v 800ma. I can turn this one all the way up to 12 or back it down to 6. Between that and the pot Ive got plenty of adjustment.

 

[ImNoExpert]

Having an issue with my fan, I think.

I've got it all wired up and the rheostat can control the speed to a point, but my fan at any speed, will speed up to high RPMs and then quickly throttle down. It will repeat this no matter how the rheostat is dialed in.

Is this normal operation for a case fan or might I have a dud? I'm running a Delta DC brushless model AFC0912DE DC12V 2.50A. My power supply is 12V.

It did this before I hooked up the rheostat and on/off switch as well. Any help is appreciated.

 

[rideincircles]

Any idea if one of these blue LED fans would work? I don't have a fan and this seems like a cool idea.

http://www.ebay.com/itm/Sleeve-Bear...t=LH_DefaultDomain_0&var=&hash=item19dff1fce8

 

[Grandpasbrewery]

For those having trouble with adjustment and not enough variation of speed, get a higher resistance rheostat.
I used a 100ohm pot with a 9v supply and I can turn it down to barely spinning to class-5 tornado.

Cheers

 

[Starrider]

I am in the process of making my own as well. Of course I have to put it to work even before it is done. I wanted to harvest some bottle yeast from a batch of Irish Red so I threw this together to get it going. It is made from parts I had lying around. The potentiometer is the wrong size so I used a transistor to control the speed. The screws are little long so the pot is a little high but the magnets are holding the stir bar quite well. Obviously I haven't bought a flask yet either but this seems to be working well.
The only cost so far is on the stir bar. Still trying to find a suitable box for a case. The power supply was repurposed from some long since gone piece of electronic gadget.
Love it when something can be done on the cheap! And SWMBO says I have too much junk lying around, ha!

 

[uatuba]

Now, just some stain and a little polyurethane and I'm good to go. I have ordered a potentiometer from Amazon, but I really don't need it seeing as how this is the highest voltage and anything lower throws the stir bar. We will see.

 

[uatuba]

Got the potentiometer in today. It's too big to fit in the box (that's what she said). So...anyone need a potentiometer?

 

[Hang Glider]

Your local radio shack probably has one of these that would work. One hot from transformer to the left or right tap (input, controls clockwise or counterclockwise rotation of pot) and the center tap to the fan...(I think...)

 

[Starrider]

Radio Shack carries pots but good luck finding one with low enough ohm rating. The lowest I could find in my area were 5k. Hooking the pot to a transistor did the trick though and easy to do.

 

[ThatGeekGuy]

Or you could just buy a prebuilt PWM controller for $6:
http://www.amazon.com/gp/product/B003L4KKF2/?tag=skimlinks_replacement-20

 

[brewkinger]

Just wanted to post my success story and say thanks.

It took me a couple of attempts, 2 different fans, 2 different power supplies and about 5 total hours of tinkering to get it right.

The 12V supply I used first was just too much (at least I thought it was).
No matter what I did, when I turned it on, it threw the stir bar.

Replaced with a 9V supply and got to tinkering.

Ended up that the "fix" was removing the rubber grommet spacers and mounting the fan flush on the underside of the aluminum backplate.
Ended up drilling a couple of extra holes in the side of the project box, just in case I ended up needing the "cooling" effect.
Better to have it and not need it than to ...... you know the rest.

Finally got it running and then proceeded to make a 1.040 wort and added some old washed WY1056 to evaluate if it could stir a more viscous liquid.

Stirring away as we speak.

 

[Starrider]

Good job. It is always satisfying when you can DIY your own.
Post a picture of your completed project.

 

[Philistine]

I made my own stir plate using the helpful instructions here. Thanks!

Video of it in action: [ame]http://youtu.be/Jx8TWLOCugc[/ame]

 

[mbbransc]

I just wanted to add an update to prices since that original post is pretty dated now. I went to Radio Shack and Home Depot and bought all the exact parts OP used for his stir plate.

Project Box (2701807) - $7.49
25OHM Pot (2710265) - $4.49
Rocker LED (2750018) - $3.49
Metal Knob (2740424) - $3.49
Quick Conn (6403134) - $2.99
Quick Conn (6404040) - $2.49
...............................--------
................................$25.44

If you use your own make-shift box and a soldering iron, you'll save yourself $13.

I also went to Home Depot and bought bolts/nuts/washers:

1/4" 2 1/2" carriage bolts (AGA) - 4 @ $0.20 = $0.80
Cut Washers 1/4" (AAA) - 12 @ $0.11 = $1.32
Hex Nuts 1/4" (000-655-414) 12 @ $0.06 = $0.72

And a washer to glue to the fan (AJB) Fender Washer - $0.14
.......................................................................---------
......................................................................$2.98


With tax, I'm up to $30 on this project. Can it be done cheaper? Yes. But I already had a parts list and picture instructions on how to do it this way. Good enough for me. I am still tempted to find a different box and save that $7.50. We'll see what I come up with.

 

[LovesIPA]

I used a small cigar humidor box. I've tried cigars off and on for years and never really acquired the taste for them. So it's worth far to me as a stirplate than as a humidor.

Edit: Please excuse my messy desk.

 

[sparksanthony]

I had a few parts on hand but somehow broke the damned computer fan when I was fooling around with it. Everything was already soldered in place too. So I had to spend an extra $12 on a new fan and cut/splice the wires..but it is working great now. Mine was still much, much cheaper than one you can buy online for 100 bones.

Thnks OP!

 

[MaxStout]

Radio Shack carries pots but good luck finding one with low enough ohm rating. The lowest I could find in my area were 5k. Hooking the pot to a transistor did the trick though and easy to do.

Try this one. 25 ohm, 3W rheostat.

 

[MDBrew69]

First, I wanted to thank Anthony for posting his instructions. I pretty much followed his build and bought the enclosure, potentiometer, and rocker switch from Radio Shack. I ended up using 3" #6-32 bolts for my fan. I glued a 5/16 x 1 5/8 fender washer to the top of the fan and used a magnet that I salvaged from an old hard drive. I found it really easy to assemble and did not have any issues with placing my magnet. I'm looking forward to using it next weekend.

http://youtu.be/kXfq9IiV-DU

 

[Starrider]

Try this one. 25 ohm, 3W rheostat.

Thanks for the link. My local RS doesn't carry it (or the 50 ohm) in either location. When I brought up your link, it said out of stock online as well. Can't seem to catch a break.

Used parts I had in the drawer, a 5k pot and a transistor. Easy hookup and allows full adjustability from full speed to slowest speed fan is capable of before stopping. This is also using a 12v supply that was found in the junk box.

Since I basically have zero dollars invested at this point, I am now on a mission to find my case the same way. Can't seem to bring myself to spend the $8 when everything else was free. I even salvaged the fan from a printer that was being scrapped.

Even buying the parts, we can build functional and quite nice units much cheaper than buying pre made. A little ingenuity and scrounging and it can be even cheaper.
For anyone real cheapskates like me, consider the radio or other electronic device that you may be throwing in the trash. Things like pots, knobs and power supplies are often easy to extract and repurpose.

 

[MaxStout]

Even buying the parts, we can build functional and quite nice units much cheaper than buying pre made. A little ingenuity and scrounging and it can be even cheaper.
For anyone real cheapskates like me, consider the radio or other electronic device that you may be throwing in the trash. Things like pots, knobs and power supplies are often easy to extract and repurpose.

I'm the same way. Before I toss some appliance, I strip off any usable parts, power supply, knobs, etc. I even lop off the cord. I have a box full of electronic parts in my basement. You never know when you'll need something...

 

[msarro]

Hey everyone! I'm going to be building one of these puppies. But since SWMBO may not be a huge fan of me having vials sitting around the kitchen, I'd like to pretty it up a bit. I haven't had a chance to read through all of this thread, but has anyone played around with using an LED fan controller instead of a normal pot?

Something like this:
http://www.xoxide.com/akust-fanspeederadvanced.html

It'll make it a bit more visually appealing, plus it'd be nice to see the RPM your stirrer is currently putting out. It also saves you from having to purchase a separate knob. The only big change would probably be that you'd need to dremel out a 3.5" hole on the front of your case instead of a simple hole.

 

[MedicMang]

Hey everyone! I'm going to be building one of these puppies. But since SWMBO may not be a huge fan of me having vials sitting around the kitchen, I'd like to pretty it up a bit.

Are you looking for "prettier" or more scientific looking? It would look cool and the rpm thing is neat, but if you are looking for it to look like its supposed to be in your kitchen, just switch out the project box for something kitchen related. Mine isn't kitchen related but I have an old wooden bible case that I'm going to use when I rebuild mine in a couple days. Going to look fancy. Be creative with yours. Hollow out a big old school cook book. Use a piece of Tupperware. Hell, build it under your counter so that it just has to sit there. How sweet would that be?

 

[misterbk]

Here are some links for people who are having trouble finding electronic components:

Newark / Farnell
See this section: Passive Components > Potentiometers > Rotary Potentiometers. They also sell knobs. I found it useful to start with a knob I like, then use the shaft type and diameter to find a pot of the right resistance. You can also ask a live chat rep for help finding something.

Digikey
Digikey can be more friendly if you're not quite sure what the official name is for what you're looking for. If you have trouble finding something on one site, try another.

Note: It's a good idea to verify power consumption if you put a pot inline with a device's power supply, since these pro shops sell lots of very low-power devices. Fans often have a current rating printed on them. If not, assume 150mA. Power is V*I = I²*R. Let's say the fan runs at full speed with the pot at halfway point. (I know it will be below full speed, just trying to find a safe maximum without measuring.) If you use a 25 ohm pot, then it will probably never exceed 0.15² * 12.5 = about 1/4 watt or 250mW. Note that the selection of pots on those sites goes all the way down to 10mW; those will be very tiny devices though.

 

[blynes]

Cheap and easy. $11.00 for the switch, pot, knob from Radio Shack. Had the rest laying around the house.

 

[day_trippr]

Huge unfocused image fail...

 

[uatuba]

Huge unfocused image fail...

It's focused for me. It's probably interlaced and your connection is slow.

 

[day_trippr]

Slow? 100 down/50 up FiOS begs to differ.

Try viewing in its native size - if you have a big enough screen (I have seven square feet of HD monitor here). It's not sharp at all. And it's ridiculously large for what it's showing.

He's been booked

 

[uatuba]

Slow? 100 down/50 up FiOS begs to differ.

Try viewing in its native size - if you have a big enough screen (I have seven square feet of HD monitor here). It's not sharp at all. And it's ridiculously large for what it's showing.

He's been booked

Verizon? Then yeah it's slow

Seriously, it's not the sharpest thing in the world, but it's detailed enough to tell what it is.

 

[Stealthcruiser]

I see it!

That countertop pattern reminds of things I used to see in the 70's though...........

 

[misterbk]

Image seems to sometimes decide to size itself down, and sometimes not. For me, last time it resized and fit within the post. Now, it shows at full size, took about 100 seconds to download, and resolution is confirmed to be 4128x2322, or slightly over twice the resolution of a full-HD screen.

tl;dr: Not Verizon. Image is definitely huge.

 

[blynes]

Yeah...my bad...took the picture on the fly with my Galaxy S4 and uploaded it. Didn't realize till I just looked at it on the computer that it was HUGE. Sorry bout that. Should be resized now.