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

rpryor said:

Yeah I threw it on the fan just so I wouldn't lose them in my room AGAIN (lost them like 4 times during multiple runs to radio shack and drinking)! The fan itself pushes them in that order but if I separate them they align perfectly on the outside but lose their strength. So I need to open up a few more hard drives here at work to stack them. Was just wondering if the hard drive magnets would be enough on the 120mm fan or should I just purchase some stronger ones?

Click to expand...

I use 1 hard drive magnet on my 120mm fan and it works great.

Thanks camiller for your information. Did not know that stacking the hard drive magnets may not help. Since the circuit works good and barrooze is using the same size fan with the same type of magnets i'll try and narrow down the placement as the error. I'll try gluing down a washer first to help raise it to the lid a little more as well. Is a 1" stir bar fine for 1000L and 2000L flask starters? Wondering if that also could be an issue.

rpryor said:

Thanks camiller for your information. Did not know that stacking the hard drive magnets may not help. Since the circuit works good and barrooze is using the same size fan with the same type of magnets i'll try and narrow down the placement as the error. I'll try gluing down a washer first to help raise it to the lid a little more as well. Is a 1" stir bar fine for 1000L and 2000L flask starters? Wondering if that also could be an issue.

Click to expand...

Yeah, a 1" bar should be fine. When you are trying to center a hard drive magnet remember that you are wanting to center the magnetic field, which with it's kidney shape may not necessarily be the physical center.

Ok so I ended up using 2 washers to push the magnets closer to the lid and used the one hard drive magnet. It did spin the bar without tossing it on all speeds. However it was a very tiny cone at maximum. Added another hard drive magnet on top and was able to get a cone to go half way down on both the 1000L and 2000L when set at maximum speed. I think my other problem for the weakness of the plate is that my hard drive magnets are quite small compared to others on the forums. Wondering if I should just purchase stronger disc magnets. Probably going to just glue it down and call it good enough for government work!

Thanks everyone for your help as well as these forums for giving me an addiction.

I built one Friday in a cigar box using these directions. I got all the parts for less than $20 and haven't built anything like this before and it actually works! Thanks for the instructions!

What do the builders of these think of this for the controller
http://www.ebay.com/itm/Computer-CP...ultDomain_2&hash=item2c6408a972#ht_3196wt_952

that would take care of the rheostat for less than from rat shack.

Csuho said:

What do the builders of these think of this for the controller
http://www.ebay.com/itm/Computer-CP...ultDomain_2&hash=item2c6408a972#ht_3196wt_952

that would take care of the rheostat for less than from rat shack.

Click to expand...

Looks like a nice find! Even if it's just the rheostat and knob, you are still money ahead from Radio Shack. It would be nice to see the back. If that uses the LM317 controller, it is a partcularly good deal.

It's too late for me. A couple of days ago I ordered all the electronic parts for 12 of them (except the fans and magnets) using the LM317s from Tayda for $25 plus $7 shipping.

Looks like a great deal, especially if there is a LM317 or some other voltage regulator involved as ThreeDogsNE said. I can't IMAGINE that is it just a plain old potentiometer mounted on a plate!

BigLuke said:

Diaperload,

You weren't by chance a recruiter in a past life were you? That first stirplate looks surprisingly similar to the old "200 card" boxes. I used to recruit in Salem, Or.

Click to expand...

No, not a recruiter. I did spend 6 years in the Marine Corps though.

I scrounged a magnet out of an old western digital hard drive and decided to up-cycle the enclosure. I'm using a 12V 0.16A 80mm fan inside. I had a 12V wall wart hooked up at first and it was way too fast. Now I've got a 5V wall wart that seems well balanced. Just need a flask!

Here is a stir plate I bought off eBay that didn't work. Turned out the rheostat need a pinch of solder. I paint job and as good as new. Got it for 30.00.



Stir plate with vortex half way down the flask

Well I salvaged a power supply from an old phone that wasn't strong enough. It ended up being only 5V. After some more looking I a cord that I didn't know what it went to so I figured it was safe to use. After blowing the lighted rocker switch and some closer inspection I saw that it said 125V. Doh! Looks like it's back to the shack for another switch and possibly a power supply if I can't scrounge another one up some where. I am determined to get this going though. Also, after going to Lowe's, Home Depot and the local hardware store I couldn't find any bolts longer than 2". I'll see how they work.

Built my stir plate yesterday out of old PC parts and bits from RS. Thanks OP! This was pretty easy, although "some" modifications had to be made to the level of the fan. I used a screw since my stir pill hasn't arrived yet. Great vortex with the screw, I can only imagine what the actual stir stick is going to be like. I am all thumbs when it comes to projects like this, so i was very pleased with the result.

Thanks again!

I just finished mine. This thing is crazy! Here it is with a 4L flask with 3L of water and a 2" bar.

Well I got the wiring all done correctly after some tinkering. I picked up a 2000 ML flask and a 1" stir bar. The fan i had laying around was a 120mm so it actually fit into the enclosure snugly. The washer seemed pretty centered. Even after all this the stir bar:would jump around and then get thrown, even on the lowest setting. My guess is it is the spacing of the magnets from each other. Now to remove the super glue and reset them.

I apologize up front if this has been answered already but I didn't have time to read through the entire thread. I have been trying for two nights to get my wiring to work with no avail.. My fan has four wires. red, blue, white, and black, My power supply has a red and a green. I have done some research about the fan wiring but I am certainly not an electrician. I tried to wire the fan directly to the power supply and tried every single wiring combination possible but still no power. If anyone could help be I would really appreciate it. Thanks.

Thanks for the build info

I built one yesterday with a single hard drive magnet and a 20 volt power supply from a computer (I used a cigar box).

I think I'll have to use a different power supply. I don't have a stir bar yet, but I think my fan is running too fast and my rheostat is getting real hot...

Deleted

divvy9 said:

I apologize up front if this has been answered already but I didn't have time to read through the entire thread. I have been trying for two nights to get my wiring to work with no avail.. My fan has four wires. red, blue, white, and black, My power supply has a red and a green. I have done some research about the fan wiring but I am certainly not an electrician. I tried to wire the fan directly to the power supply and tried every single wiring combination possible but still no power. If anyone could help be I would really appreciate it. Thanks.

Click to expand...

Four wire fans typically use the fourth wire for PWM speed control and require a signal (21-28kHz) on that wire to operate at all. This is not something you will be able to easily bypass as far as I know.

So I am using a 5v phone charger and a 4" fan from radio shack, the one that lights up. It would spin before I wired in the pot, now with it all wired up it does not work. Do I need a more powerful power source?

I used a 30A 12 VDC switch, and it lights up just like it should when turned on. The fan just doesn't come on. The fan had an extra yellow wire labeled Y on the fan, I just cut it off as the fan worked without that wire hooked up to anything. Any help is appreciated!

Third edit: I am pretty sure the wall wart phone charger is to blame. I am now in search of a 12V one.

mrkrausen said:

Well I got the wiring all done correctly after some tinkering. I picked up a 2000 ML flask and a 1" stir bar. The fan i had laying around was a 120mm so it actually fit into the enclosure snugly. The washer seemed pretty centered. Even after all this the stir bar:would jump around and then get thrown, even on the lowest setting. My guess is it is the spacing of the magnets from each other. Now to remove the super glue and reset them.

Click to expand...

Tisk, tisk, is that glue on your fan blades?

Thanks for this thread, I just built one myself.

On a side note, how i got the HD magnet separated, was I had 2 wrench grips and then bent the metal that was holding it. once it was bent the magnet easily came off. and that way I didnt have to worry about cracking/breaking the magnet.

The metal was fairly soft too.

Thanks so much for this idea and the expertise you brought to the table. Fortunately I had enough old garbage lying around that the only thin I needed to buy was the stir bar itself. I used an old computer power supply fan, its housing and its rocker switch. I took a rheostat out of an old junked CB radio for my speed control. I found that the 6V cell phone charger wasn't providing enough juice for the fan, so I spliced the computer P/S cord into a 12V motorcycle battery tender. As soon as my beaker and stir bar arrive it'll be time to test it out - just in time for my next batch!

Andy

Got my first starter spinning right now for my LHBC Big Brew I will be bringing home Saturday. I started it yesterday evening. 3L starter using Wyeast 1187 Ringwood Ale.

Just whipped this up. Great thread and instructions.

Can one use something like a bolt (with the head cut off) covered in heat-shrink tubing instead of buying a "stir bar"?

Newsman said:

Can one use something like a bolt (with the head cut off) covered in heat-shrink tubing instead of buying a "stir bar"?

Click to expand...

I would lean towards no. Stirbars are magnets as well and I think that makes a big difference. I think you also might run into some sanitation issues with the shrink tubing.

Newsman said:

Can one use something like a bolt (with the head cut off) covered in heat-shrink tubing instead of buying a "stir bar"?

Click to expand...

I will give a definitive No, because the object on top has to be magnetized, otherwise you will have unpredictable spin patterns, and that will cause all sorts of problems. Just pony up the 4$ for the stir bar... it will be worth it

Also make sure you get a stir bar with a pivot roll in the center. It will make the spinning a lot easier, and when the yeast starts to build up you will have problems with it if you dont... That is the problem I ran into, now I have a bar with a pivot and its great.

I just got a 115 volt ac fan and was wondering if it will work and I'd there was any thing I could use to control speed

I finished making my first stir plate tonight. I had some trouble with the stir bar until I raised the fan about a half inch or so inside the box. Once I did that, I was golden!

Is there a reason for using a washer larger than the center of the fan? Also, should my two magnets be set to have the same poles facing up or should one be "N" and the other "S"?

you need to arrange them so that opposite poles face up.

So one should be set with N facing up and the other with S?

janitorjerm said:

So one should be set with N facing up and the other with S?

Click to expand...

Yes, that's the only way it can keep the stirbar properly oriented.

10-4. Any reasoning behind the larger washer?

Gives me more play with the magnets. If you're never going to need a larger stir bar than 1", a smaller washer is fine. That and a larger washer is what was lying around.

I'm in the process of making one of these and had a question about the size of the holes to drill for the knob and rocker switch? I want this to look neat, unlike my temp controlor I made! Also, this may be a dumb question, but I still can't wrap my head around the polarity issues with the magnets. I have two smaller magnets I harvested from a HD.

Compare the switch and rheostat sizes to drill bits you have. I used the largest I had on hand (a little too small) then used a small file to increase the size.

The stir bar has a north end and south end. You need to position your magnets to attract a north polarity on one side, and a south on the other. The north polarity on the stir bar aligns with the south on your stir plate and the south on the stir bar aligns on the north of the stir plate. Just place the stir bar on some magnets before hand and try flipping the magnets over. The stir bar will only attract one way.

Thanks Yaason, I knew I was making things harder than they are!!

So why do you need a speed control? Do you start out fast then slow down as you get more slurry, or do you need to tweak the speed for different types of yeast? K I'm just wondering if you really need the speed control, or if you can just use a resistor to set a fixed speed.