Show us your DIY stir plate!

[DrunkleJon]

I am so very jealous. Your Erlenmeyer flasks all have such smooth bottoms. When I spin my 1 inch bar up it sounds like my LHBS bought flask is stirring a marble or two. Though with a lot of fiddling I can find the one spot where it is almost unnoticeable when you are not in the same room as it.

 

[reverendnathan]

I used and a trip to fry's. Local liquor store sells the empty cigarette boxes when they are done, so I grabbed the nicest one and started from there. You'll notice I don't have a potentiometer on it... well, fry's doesn't sell 'em and by the time I was building this I left it out. That "box" in the lower right controls the speed in place of a knob, but I found starting it at full RPM doesn't lose the magnet.

I actually bought a stirplate from the LHBS because the replacement bars they sell are only large, and I couldn't get a large bar to work no matter what I did. So now I have two plates, two bars, and the altogether potential to make a huge starter.

I have a second, very long cigar box I plan on making a "double stirplate" with, which has two fans and can stir two different starters at two different speeds. Seems like it would be pretty cool if I can get it to work.

 

[theBFG]

Thanks to this and many other threads, I finished my DIY stir plate! Can't remember the exact costs, but mine was a litte more expensive than some, probably about $25-30 all said and done. That being said, it was still a heck of a lot cheaper than buying a new one!

Here she is (note I added the black velvet top at the end to protect the flask from the exposed screw heads):

 

[LoloMT7]

I had this linksys router laying around that didn't work so I removed the circuit board and mounted a 12V computer fan in it with a couple of small hard drive magnets. I cut a usb cable off of an old computer mouse and wired to the fan.. then a simple USB to wall adapter and i'm good to go. Didn't bother with a rheostat but I'll wait and see how the 2" ebay stir bar works and then decide if i need to add a rheostat inline and use a 9-12V cable instead..

 

[poislb]

Just finished mine, works like a champ. The only problem I had was setting the magnets just right so it wouldnt throw the bar. I may buy a 9v adapter instead of using the 12, a little to much power right off the bat.

 

[LoloMT7]

What size is your stir bar? Now that I got my stir bar in I'm having all kinds of problems getting the magnets set right it is like they are 2 week maybe? Its a 2 inch bar... ive tried all kinds of different rare earth magnets and placements... one on each side one offset... 2 opposite everything.. tried volts from 5 to 12... its like the magnets don't grab the bar and do any thing with it... grrrr im gonna go watch football.. Maybe buy some bigger rare earth magnets tomorrow..?

 

[poislb]

What size is your stir bar? Now that I got my stir bar in I'm having all kinds of problems getting the magnets set right it is like they are 2 week maybe? Its a 2 inch bar... ive tried all kinds of different rare earth magnets and placements... one on each side one offset... 2 opposite everything.. tried volts from 5 to 12... its like the magnets don't grab the bar and do any thing with it... grrrr im gonna go watch football.. Maybe buy some bigger rare earth magnets tomorrow..?

Mines a 2 inch bar, but as ya can see the center has that hump. I guess it creates less friction somehow and lets it spin more freely. I have the 3/8 earth magnets i bought from harbor freight, I use 2 on each side stacked. Try moving the magnets farther apart, that might help. Im now using a 7.5 volt adapter 200ma. Got any pics? how far are the magnets from the base, maybe wanna try getting it closer to the base to give more surface contact, without it hitting of course.

 

[LoloMT7]

Mine has the band around the middle also. I pulled the whole thing apart and had the flask right on top of the fan still nothing though... think all these magnets are 2 weak.. i tried spacing them way out etc... think ill try harbor freight here tomorrow. Thanks.

 

[241]

This is fantastic. I have a bunch of old crud that needs a purpose so this just hit the top of my build list!

 

[adamreef]

BFG,

My build is almost identical to yours (same box & fan), but mine keeps throwing the stir bar. I have tried s hard drive magnet and 3/8 round neodymium magnets with various spacing. What did you use? How much space between the magnets and the back side of the lid of the box?

Thanks!

Adam

 

[Spargeking]

Here is my $20.00 Stir Plate. It about an hour to build. I did my first starter on it this last week and just pitched the Yeast. It seems to worked great. I used a 10K ohm POT, not much control. If I was doing it again I would change to 100 ohm.

 

[LoloMT7]

Mines a 2 inch bar, but as ya can see the center has that hump. I guess it creates less friction somehow and lets it spin more freely. I have the 3/8 earth magnets i bought from harbor freight, I use 2 on each side stacked. Try moving the magnets farther apart, that might help. Im now using a 7.5 volt adapter 200ma. Got any pics? how far are the magnets from the base, maybe wanna try getting it closer to the base to give more surface contact, without it hitting of course.

Well after a very frustrating weekend of playing with magnets (should have been brewing). I finally figured out that the 5 dollar ebay spin bar I got just wasn't working for me. If I dropped a nail or screw or anything else in the flask it would spin just fine! I tried spacing magnets further apart or closer together, changed magnets, voltages, spacing up and down and on and on... It just wouldn't do anything but bounce the stupid stir stick around or throw it to the side.

I finally found this page and built my own spin bar out of 5 small earth magnets and some tubing and sealed the ends closed. Dropped it in and it spins perfectly now.
http://kbcbeer.com/stirplate.html

I ended up scraping the router shell in the end as I didn't like the way the flask sat on it with the top of the router being curved etc..

Final build:

12 Volt 80mm fan (had laying around)
1 hard drive magnet placed just off center
8 Volt DC wall adaptor (from an old logitech remote charger)
Lid from Droid Razr Maxx box
2000ML Flask only 15.95 at LHBS that's cheaper then I found online
5 neodymium rare earth magnets for the homemade stir bar


I do have a question. Are stir bars supposed to be magnetic? Or just have metal in them? This one I got on Ebay acts like it has a super weak magnet in it maybe? It won't even hold itself to the refrigerator..

Thanks all.. Here are a few pictures of my now working stir plate :rockin:

 

[Hang Glider]

I've never had a stirbar that held itself to a refrigerator... so your's is normal.

 

[Spargeking]

I also purchased my Stir Bars from eBay. I received 5 of them in the lot that I bought. When I first played with my Stir Plate I did have the Bar I was trying keep flying off, even when running the Fan at a very slow speed. I thought that something was wrong with they way I had set everything up. Come to find out, that particular Stir Bar was not as magnetic as the rest. I have no problems running the Plate at full speed with the other 4 Stir Bars.

Yes they are magnetic, and all of them stick to the Refrigerator. At least the ones that I bought ( I have never been around others so all I can attest to are mine). They in fact are pretty strong for what they are. If you are using strong Rare Earth Magnets you might try lowering the fan in the box, or not using as may Magnets (stacked up). I found when building mine that bringing that magnetic field further away from the actual Stir Bar made thing much better. With the opposing poles on the two Magnets glued to the fan, I think the field was so strong when it was so close to the Stir Bar that it was causing problems. At least that is my hypotenuse with complete and total unfounded scientific backup (really just a guess). Mine worked much better with about a 3/4" gap between the fan and the were the Stir Bar sits. Good luck.

 

[theBFG]

BFG,

My build is almost identical to yours (same box & fan), but mine keeps throwing the stir bar. I have tried s hard drive magnet and 3/8 round neodymium magnets with various spacing. What did you use? How much space between the magnets and the back side of the lid of the box?

Thanks!

Adam

Hey Adam -

Sorry it took me a while to get back to you, I've been out of town on business...

Anyway, this is my parts list below:

1"Magnetic Stir Bar Plain PTFE 6 x 25mm
1"Thermaltake Mobile Fan II External USB Cooling Fan - Us"
1"N45 Dia 1/2" x 1/16" Disc , Package of 10 Rare Earth Neodymium Magnets"

The rare earth magnets I spaced about about an inch or so apart. Essentially they are on either side of the middle circle in the fan, if that makes sense. Sorry I don't have a picture of the inside, perhaps I can get one this weekend when I get back home if it helps. I think I used 3-4 on each side. Getting the fan close enough to the lid of the box was the trickiest part for me. Basically I took the screws that held the fan guards on and drilled through the lid and suspended the fan with them. In order to do that, the fan is hanging a bit and the screws go through the lid and through the first set of holes on top the fan such that the fan is hanging from the lid and is just low enough so that the magnets are not hitting the lid when they spin. I tried to get it as close as possible and it seemed to work.

The only problem I have is it doesn't like to stay on full power without throwing the stir bar. I will try to adjust this in the future, but for now I leave it on about half power which keeps everything stirring nicely and is probably ok. I'm not sure if that helps at all, if you need more help shoot me a message and I'll try to explain it a little better or send you a picture this weekend when I get home. Cheers!

 

[poislb]

I also purchased my Stir Bars from eBay. I received 5 of them in the lot that I bought. When I first played with my Stir Plate I did have the Bar I was trying keep flying off, even when running the Fan at a very slow speed. I thought that something was wrong with they way I had set everything up. Come to find out, that particular Stir Bar was not as magnetic as the rest. I have no problems running the Plate at full speed with the other 4 Stir Bars.

Yes they are magnetic, and all of them stick to the Refrigerator. At least the ones that I bought ( I have never been around others so all I can attest to are mine). They in fact are pretty strong for what they are. If you are using strong Rare Earth Magnets you might try lowering the fan in the box, or not using as may Magnets (stacked up). I found when building mine that bringing that magnetic field further away from the actual Stir Bar made thing much better. With the opposing poles on the two Magnets glued to the fan, I think the field was so strong when it was so close to the Stir Bar that it was causing problems. At least that is my hypotenuse with complete and total unfounded scientific backup (really just a guess). Mine worked much better with about a 3/4" gap between the fan and the were the Stir Bar sits. Good luck.

Yes, you are correct that lowering the box with earth magnets help a ton. Also I found out that a 50 or 100 ohm rheostat potentiometer works a hell of alot better that the suggested 25 ohm. Hook that up with a 12 volt power supply and ya can really dial in the speed like a true lab stir plate...At full bore I never throw a bar with a 2000 ml starter..

 

[brew2enjoy]

Well after a very frustrating weekend of playing with magnets (should have been brewing). I finally figured out that the 5 dollar ebay spin bar I got just wasn't working for me. If I dropped a nail or screw or anything else in the flask it would spin just fine! I tried spacing magnets further apart or closer together, changed magnets, voltages, spacing up and down and on and on... It just wouldn't do anything but bounce the stupid stir stick around or throw it to the side.

I finally found this page and built my own spin bar out of 5 small earth magnets and some tubing and sealed the ends closed. Dropped it in and it spins perfectly now.
http://kbcbeer.com/stirplate.html

I ended up scraping the router shell in the end as I didn't like the way the flask sat on it with the top of the router being curved etc..

Final build:

12 Volt 80mm fan (had laying around)
1 hard drive magnet placed just off center
8 Volt DC wall adaptor (from an old logitech remote charger)
Lid from Droid Razr Maxx box
2000ML Flask only 15.95 at LHBS that's cheaper then I found online
5 neodymium rare earth magnets for the homemade stir bar


I do have a question. Are stir bars supposed to be magnetic? Or just have metal in them? This one I got on Ebay acts like it has a super weak magnet in it maybe? It won't even hold itself to the refrigerator..

Thanks all.. Here are a few pictures of my now working stir plate :rockin:

Perfect. I have a Droid box sitting around too.

 

[LoloMT7]

Perfect. I have a Droid box sitting around too.

I gotta say I'm really happy with this stir plate now but it took me a lot of screwing with to finally figure out it was the stir bar that was the problem. I mean seriously who would have guessed that? My buddy brought his stir bar over last night we dropped it in and it worked fine. Tried mine and it still wouldn't work. Yes they are exactly the same bar both 2" inch with the center ring on them. Go figure that out. But I'm perfectly content using my homemade stir bar and can't wait to get back to brewing now.

For the final test I sent him home with my stir bar to test on his stir plate. All I got was a txt message that said "Well it's not just your plate man I threw it away"

 

[brew2enjoy]

Made mine last night. Thanks LoloMT7 !

 

[LoloMT7]

Made mine last night. Thanks LoloMT7 !

Cool glad it worked out for you.


Nice coaster by the way! This is my tap handle i bought from a guy on ebay

 

[Huaco]

Man, The Dallas Defense was ALL OVER Vick like a pack of Wild Dogs!


..........ZING..............

 

[brew2enjoy]

Man, The Dallas Defense was ALL OVER Vick like a pack of Wild Dogs!


..........ZING..............

yes, yes they were. Pretty bad when a team can actually make Dallas look good.

 

[Huaco]

Yeah, I am pretty bummed as a cowboy fan. But then again, I am used to it. Nothing will change 'till Jerry released the GM role to a competent individual.

Did you get the pun?

 

[brew2enjoy]

Cool glad it worked out for you.


Nice coaster by the way! This is my tap handle i bought from a guy on ebay

well, I haven't tested it out yet because I don't have a stir bar, but it seems to spin pretty good when I put a screw on it.

Nice tap handle!

Yeah, I am pretty bummed as a cowboy fan. But then again, I am used to it. Nothing will change 'till Jerry released the GM role to a competent individual.

Did you get the pun?

yeah, I got it Vick's days in Philly are numbered thankfully. It's time to move on and see what Foles can do.

 

[brew2enjoy]

stir plate is finished now. Added the switches over the weekend

 

[LoloMT7]

stir plate is finished now. Added the switches over the weekend

Looks great. And just FYI my starter over-flowed on me onto the razr base and it wipes right off of that slick finish they have. Really happy with it.

 

[Gitmoe]

Finally had time to build mine today. I ended up spending more than I would've to just buy a stir plate but whatever. This one is waaaaaay classy...

The speed control knob is actually countersunk into the box. The box was too thick to mount the rheostat so I had to use a forstner bit to make the area thinner.

The build was expensive because I ended up buying a brushless motored fan. Whisper quiet...

 

[Jester]

Finally had time to build mine today. I ended up spending more than I would've to just buy a stir plate but whatever. This one is waaaaaay classy...

The speed control knob is actually countersunk into the box. The box was too thick to mount the rheostat so I had to use a forstner bit to make the area thinner.

The build was expensive because I ended up buying a brushless motored fan. Whisper quiet...

GREAT build!!! What is your connection on the backside of the cigar box?

 

[Gitmoe]

GREAT build!!! What is your connection on the backside of the cigar box?

I put the power switch on the back. Wanted the front to look as clean as possible. Making it look good was the only way my wife would let me keep it on the counter...

 

[awarner322]

Here is my lego stirplate