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

[Accidic]

I appreciate what you are trying to accomplish with using what you have. Can I just say from my experience in the DIY stir plate that having to match things like mili volts and amps with rpms and all the other variables is an absolute pain in the uterus! Unless you are a electric nerd that goes to robot wars I would strongly suggest the simple approach and buy a Fan like this
Video Link: http://www.amazon.com/gp/product/B002OJN250/ref=ox_sc_act_title_2?ie=UTF8&m=ATVPDKIKX0DER
The knob is relocatable and all you need is a USB wall wort and you are spinning!

Volts are typically only necessary to be in the ballpark (and not above) and a little lower is probably better anyway and with most fans 12v that is absurdly easy. Amps are the most important to match or exceed with your power supply. If you'd struggle to do either of these and your going to spend that kind of money, why not spend the extra $10-20 and get one with a good warranty and not mess with it at all?

 

[HenryVance3]

Bravo! Any issues with magnetism due to the thickness of the awesome case?

 

[two_hearted]

Bravo! Any issues with magnetism due to the thickness of the awesome case?

None yet. Although I have no frame of reference with this being my first and only stirplate experience. Seems to get a near 2 L of water going just fine with a couple inch deep vortex.

 

[Brickout]

Another stir-plate gets its spins!

<--Video

 

[JimmyD]

Simple design. Computer cooling fan, old phone charger, switch and cigar box. Works great.

 

[two_hearted]

Why do you set the flask right on the fan instead of closing the lid?

 

[mcshaw16]

Hi,

I am currently working a variation of this build, using a cigar box for a project box and magnets that I got from work. For now I just had the fan wired a 5v cell phone without the rocker switch and rheostat hooked up while I was trying different configurations with the magnets. I am using small round 1/2" diameter magnets that I got from work, they are very strong.

Several days after I mounted the magnets, my fan suddenly does not work. It had been working great, but now when I plug it in it spins very weak a couple revolutions and then stops. Is is possible that my magnets were too strong and demagnetized the fan motor?

I will post a pic when I get a minute.

 

[mcshaw16]

Hi,

I am currently working a variation of this build, using a cigar box for a project box and magnets that I got from work. For now I just had the fan wired a 5v cell phone without the rocker switch and rheostat hooked up while I was trying different configurations with the magnets. I am using small round 1/2" diameter magnets that I got from work, they are very strong.

Several days after I mounted the magnets, my fan suddenly does not work. It had been working great, but now when I plug it in it spins very weak a couple revolutions and then stops. Is is possible that my magnets were too strong and demagnetized the fan motor?

I will post a pic when I get a minute.

I checked my wiring and that all looks good, any help would be appreciated.

 

[mcshaw16]

Belay my last. I gave the fan a few spins while plugged in and it took off and it's working fine now. Still not sure what the problem was.

 

[richkev]

Not sure if your fan came from an old computer, but if it was like mine, it probably had several years of accumulated ghost turds built up in the housing. Works like charm, though!

 

[emjay]

Belay my last. I gave the fan a few spins while plugged in and it took off and it's working fine now. Still not sure what the problem was.

The adapter may not be giving it the juice it needs to start properly. 5V is kind of low, especially since that will be the upper end of what the potentiometer will allow. But it could also be an amperage issue.

How many mA does can your adapter output? And you you have the voltage and amperage specs, and/or the make & model of the particular fan you're using?

 

[LabRatBrewer]

I've searched, I've read and read (this is a long thread, and the similar thread are long). My simple stir plate is in a small cigar box, 12v fan and a 12v wall wart charger. My fan (5 inch, maybe 5.5) runs slow. The rheostat seams to have no noticable effect. My stir rod just dances. I can get it to run in a circle (not really spin) if I double-stack [two on each side-reversed poles] the batteries. (I have a small bunch of dime sized/shaped rare earth magnets form an unrelated project).
my questions:
1: Do I want the fan to spin faster?

2: Although counter-intuitive, would the fan spin faster if I LOWERED the voltage? i.e. am I better off with a 6 or 9 v charger?

As always, thanks in advance...cheers.

 

[tmd49]

I've searched, I've read and read (this is a long thread, and the similar thread are long). My simple stir plate is in a small cigar box, 12v fan and a 12v wall wart charger. My fan (5 inch, maybe 5.5) runs slow. The rheostat seams to have no noticable effect. My stir rod just dances. I can get it to run in a circle (not really spin) if I double-stack [two on each side-reversed poles] the batteries. (I have a small bunch of dime sized/shaped rare earth magnets form an unrelated project).
my questions:
1: Do I want the fan to spin faster?

2: Although counter-intuitive, would the fan spin faster if I LOWERED the voltage? i.e. am I better off with a 6 or 9 v charger?

As always, thanks in advance...cheers.

I have built six of these types of stir plates. I found out two things: if the magnets are not directly in the center of the spin it will throw the stir bar and too much power too soon will throw it for sure. Lowering the total voltage into the unit allowed the stir bar to get hold of the spin and thus speed up gradually. I tried using a 13 v and then a six volt wall adapter and the 6V worked every time.

 

[TrainSafe]

I've searched, I've read and read (this is a long thread, and the similar thread are long). My simple stir plate is in a small cigar box, 12v fan and a 12v wall wart charger. My fan (5 inch, maybe 5.5) runs slow. The rheostat seams to have no noticable effect. My stir rod just dances. I can get it to run in a circle (not really spin) if I double-stack [two on each side-reversed poles] the batteries. (I have a small bunch of dime sized/shaped rare earth magnets form an unrelated project).
my questions:
1: Do I want the fan to spin faster?

2: Although counter-intuitive, would the fan spin faster if I LOWERED the voltage? i.e. am I better off with a 6 or 9 v charger?

As always, thanks in advance...cheers.

I rink you want slower speeds, at least to start with. If you have a lower voltage power supply laying around, try it.

It also sounds like you may need stronger magnets or better positioning of the existing magnets.

 

[mcshaw16]

The adapter may not be giving it the juice it needs to start properly. 5V is kind of low, especially since that will be the upper end of what the potentiometer will allow. But it could also be an amperage issue.

How many mA does can your adapter output? And you you have the voltage and amperage specs, and/or the make & model of the particular fan you're using?

My adapter output is 800mA, I do not have the fan specs handy at this time. But for now it seems ok I guess, starts normally now when I plug it in now, and pulls a decent vortex in my flask.

The next time I have the fan unmounted I will take a look at the specs.

 

[WrathsU]

Thanks for the information! I made my own today and all I needed to buy was the rheostat and the knob!

Today I made a stir plate! | Austin's Beer Blog

 

[ShackNasty]

Just built this today. Thanks for the detailed instructions !

 

[coypoo]

Working on mine now. Just ripped apart my old HD for the magnets and fan. Tomorrow I hope to procure my rheostat, switch, and cigar box as well as place an order for a 2L flask and stir bar. Can't wait to getting going

 

[3PegBrew]

subscribed

 

[coypoo]

First attempt: fail. Getting stronger magnets tomorrow.

 

[tmd49]

Here are my stir plates. If you need one...I'm just saying.

 

[TrainSafe]

First attempt: fail. Getting stronger magnets tomorrow.

I had the same problem with the hard drive magnets. They just don't have enough strength.

I purchased the neo disc magnets recommended about 5 pages ago and they work perfectly.

 

[coypoo]

I had the same problem with the hard drive magnets. They just don't have enough strength.

I purchased the neo disc magnets recommended about 5 pages ago and they work perfectly.

Good to hear. I'll look for those when I get out today or tomorrow

 

[MrTheKing]

Double time to sit around twiddling my thumbs at work -

 

[coypoo]

I got some good magnets but my fan spins too fast, so I need to get a resistor (I don't have any power cords that are less than 9V). Do I put it before or after the rheostat?

 

[Accidic]

You can go small in series or as a voltage divider so long as it's large enough to cover the power needs.

 

[coypoo]

You can go small in series or as a voltage divider so long as it's large enough to cover the power needs.

Would a 1/2 watt 100 ohm be good? I'm terrible with electricity stuff, so im just guessing at all of the different watt/ohm combination resistors

I wish I had a 6V power cord.....

 

[emjay]

Would a 1/2 watt 100 ohm be good? I'm terrible with electricity stuff, so im just guessing at all of the different watt/ohm combination resistors

I wish I had a 6V power cord.....

WTH is a 6V power cord? I assume you mean a wall wart/AC adapter?

 

[coypoo]

Yes.

 

[Accidic]

I would see this atm when i'm 3 sheets to the wind. Just keep in mine I'm about a liter of vodka and a little over a bottle of champagne in so gauge accordingly.


Now for attempt number two at typing this.... That resistor should be safe up to 7v depending on how you wire it. As with anything, check it for heat before leaving it unattended after some test time and you should be fine. I presume your comfortable with a little testing as you can buy a complete unit for $40 or less with a warranty. also, be careful if you go the VD route as I just either fried a fan from that or (more likely) lack of magnet balance.