How to use a Stir Plate

[ShortSnoutBrewing]

Ladies and Gents...I purchased a homemade cigar box stir plate from a guy listing on craigslit. First time we meet he brought a flask and stir bar along to demonstrate how it worked. Sadly, the stir bar kept jumping off and he was quite embarassed and refused to sell to me. We set up a meeting for the next week after he had a chance to go home and play with it some more.

We meet again, with a new box but we were unable to take the stir plate for a test run. I purchased anyway.

Fast forward about a month and I finally have a flask and stir bar. Test out the plate last night and I had the same issue. The bar will start to spin, but only if I plug in slowly, but then jumps off if I attempt to completly plug in the plate.

I'm using a 2L flask with a 1 3/8" bar. Is it the plate, me, or the size of the flask/bar?

 

[WortMonger]

Hmmm, what kind of control do you have, I had problems with mine because it spins to fast. Using water to test isn't accurate because wort is thicker and slows down the stir bar a little. I fixed my problem by adding paper underneath the starter jar until I kept it on center and spinning.

 

[fretman124]

I haven't used mine yet (just made it and am waiting on the stirbar and flask) but I've been reading everything I can on the subject. Consenus seems to be to adjust the hiegth of the stribar from the magnets. With that in mind I made mine so I can adjust the hiegth of the fan inside the box. hoping it works.....

 

[cge0]

Playing with the stirrer at lab showed me that if the magnet flies off, you're moving it too fast. I suggest attaching something to control the voltage.

 

[Mustangj]

Is the the bottom of the flask convex?

I had this same problem I had to use a 1'' 3/8 bar and it works geat 1000ml flask.I have also uesd a growler.

 

[SuperiorBrew]

If your flask is flat then it has to be spinning too fast, try raising the flask up away from the magnet it may slow it down enough to make it work till you can get a control on it.

 

[ShortSnoutBrewing]

Thanks for all the responses. I felt like it was moving too fast. It doesn't have a control on it. Just plug in or unplug. I'll search around to see how to add some control to it, or see if I can adjust the height a little.

 

[aekdbbop]

sorry for the hijack~

when you use a stir plate, should you use a foam stopper or an airlock?

 

[Kubed]

sorry for the hijack~

when you use a stir plate, should you use a foam stopper or an airlock?

I use a piece of aluminum foil to cap my flask. There is a danger, be it a small one, that an air tight seal will allow enough pressure to build up in the flask and send shards of glass everywhere. I could use an airlock, but foil is 1) way, way cheaper and 2) won't get overwhelmed no matter how much gas is getting blown off

 

[Scimmia]

Foil is usually suggested for starters because it lets some oxygen in, which is actually a GOOD thing with starters.

 

[germanskyy]

Kilted Brewer,
I just made a stir plate and had the same problem. I was spinning too fast with my 10 V DC plug in. Firstly, I have nylon spacers within my enclosure to move the fan away from my flask 1/4"....that helped. It was still spinning too fast though so I added a 100 Ohm resistor from Radioshack inline before the fan....worked great! spins enough to create a 1-1/2" tail on the whirlpool, which is enough to drive off the CO2 and keep everything moving around nicely. Good Luck

 

[SuperiorBrew]

sorry for the hijack~

when you use a stir plate, should you use a foam stopper or an airlock?

I use foam but either the foam stopper or tin foil, airlocks not recomended

 

[BeerCanuck]

I haven't made a stir bar plate yet...I have not heard anyone review with starburst model stir bar....a little extra $ but a better design I think.

my 2 cents
BeerCanuck

 

[Seabee John]

I haven't made a stir bar plate yet...I have not heard anyone review with starburst model stir bar....a little extra $ but a better design I think.

my 2 cents
BeerCanuck

I too saw this and thought it would be better... but figured if my starter is stirring with a regular bar it's probably doing everything that can be done. I just don't see how this would improve things.

 

[mot]

hit up local pawn shop and replace the converter with a lower volt one

 

[germanskyy]

hit up local pawn shop and replace the converter with a lower volt one

Agreed..my converter was 10 V....from a very old sega genesis...I felt like I killed part of my childhood by when I was cutting up that converter

I made a second one to barter for welding services with a 5 V DC and I worked great, about the same as the 10 V with 100 Ohm resistor. But you can probably hit up a friend, I went to the pawn shop and they didn't want to help me, everyone has these things laying around anyway.

 

[WortMonger]

I fixed my spinning problem with 8 folds of paper. If I made mine again I would just use one of those adjustable voltage converter plug-ins. You know the ones you can switch by sliding the little bar from like 2.5, 5, 7.5, 9, 12, 18, 24. That sould be ok for a stir-bar control shouldn't it?

 

[Bobby_M]

My box is going to be an old fried computer powersupply. It's already got the fan mounted and a fan control switch, slow medium and fast. If that part of the supply is fried too, I'll just wire in different resistors to acheive the same.

 

[Seabee John]

I fixed my spinning problem with 8 folds of paper. If I made mine again I would just use one of those adjustable voltage converter plug-ins. You know the ones you can switch by sliding the little bar from like 2.5, 5, 7.5, 9, 12, 18, 24. That sould be ok for a stir-bar control shouldn't it?

try this https://www.homebrewtalk.com/showthread.php?t=41553

 

[WortMonger]

Thanks for the link Seabee John, but it didn't really answer my question. I am using a train controller and it still spins to fast. I was asking specifically about the transformer.

 

[Scimmia]

To answer your question, it might work, but the steps might be too much and still give you problems. If you're using a train controller, you should be able to get the voltage down and slowly ramp it up, much better than those selectable supplies.

 

[Joker]

I saw a great how to on these last night and the recommendation was to build it so the fan is adjustable for height. And using a cell phone power cord about 7V seemed to work the best. They did have dials to adjust speed but stated they rarely used them.

 

[WortMonger]

Yeah, my lowest setting on the train controller is still too high and that is how I fixed the problem was stacking paper until it worked.

 

[ShortSnoutBrewing]

I saw a great how to on these last night...

Was there a brew crew meeting last night?

 

[Joker]

Was there a brew crew meeting last night?

Yep there was, and yes that is where they were showing a couple designs.

 

[Seabee John]

Yeah, my lowest setting on the train controller is still too high and that is how I fixed the problem was stacking paper until it worked.

I purchased a fan for NickStecks' Bare Bones Stirplate (should I trade mark that name?) It had a 3 position switch attached to the fan. The voltage supplied from the intended computer would have been a constant. So they built in the switch for 3 different speeds. The lowest speed combined with the lower setting on Nick's model is not enough to spin the magnet. The fan was one of those blue LED dealies at Circut City. It ran about 10 bucks. Maybe a different fan is the ticket??? who knows. One quick question though... what is the output voltage of your controller? 6v, 12v, or 18v?

 

[WortMonger]

I'm on a 18V controller. That is why I feel the separating with a barrier is the ticket.

 

[Seabee John]

I'm on a 18V controller. That is why I feel the separating with a barrier is the ticket.

odd. I'm running output 0-18v as well. what size magnet are you using for a stirbar? I know the shorter the bar the faster the stir can be. I'm using 1"

 

[WortMonger]

odd. I'm running output 0-18v as well. what size magnet are you using for a stirbar? I know the shorter the bar the faster the stir can be. I'm using 1"

1" stir bar here. I don't know why the controller doesn't eek out the voltage on the lowest setting, but I wish it did. It would be so much better with a resistor to step down the voltage a little in my case, but the papers don't bother me for now. I will make this upgrade a little later on.

 

[ShortSnoutBrewing]

Wow, there was more action here than I thought. Damn "new posts" shortcut not bringing everything up...

I'm using a 12v power supply on mine. I took the fan off the other day trying to create some more space between magnets and the bar. It didn't work, but I did notice something I wasn't expecting. There was just one magnet in the center of the fan. I thought there should be two pieces of magnet?!?!? Could that be part of the issue?

The guy that made it for me swears he was using it just fine with a 1l flask and is being cool about the whole thing. I'd just love to get it working!

 

[Scimmia]

That depends on the magnet, I'm guessing it's probably a crescent shaped magnet from a hard drive, in which case, 1 is fine.

 

[ShortSnoutBrewing]

You are correct. Scratch that one off the list I guess.

 

[WortMonger]

That depends on the magnet, I'm guessing it's probably a crescent shaped magnet from a hard drive, in which case, 1 is fine.

I concur, I made my first attempt with two magnets, but it works much better with just one of the crescent shaped hard drive magnets.

 

[conpewter]

Considering I'm short on funds but making one of these would be cool... what's the issue with using a old power supply from a computer to go ahead and run the fan? I know I may have to put some resistors in to lower the speed but just wondering....

Would be sweet to just mod my old desktop tower that I don't use and put the fan/magnet combo right under the top of it so I could set a flask right on top and just turn the computer on and let it run hmm... thoughts?

 

[Scimmia]

Considering I'm short on funds but making one of these would be cool... what's the issue with using a old power supply from a computer to go ahead and run the fan? I know I may have to put some resistors in to lower the speed but just wondering....

Would be sweet to just mod my old desktop tower that I don't use and put the fan/magnet combo right under the top of it so I could set a flask right on top and just turn the computer on and let it run hmm... thoughts?

Couple of problems I see, first is that it's usually better to have some kind of speed control, so you're not just flipping it from off to full speed. Way too easy to throw the bar that way.

Second is that, assuming your computer case is metal, it'll act as shielding and you won't get much magnetism though it, so you'll have a hard time moving the stirbar.

 

[conpewter]

That's a good point, maybe i'll do some experimentation with using a power supply though and somehow putting a controller in line, I've just never been into train sets ) thanks!

 

[McKBrew]

I acquired a computer supply box a few days ago and instantly thought "stirplate" Guess I'm not the first. The box is the perfect shape and size for the base. I am going to gut the box and figure out what I can re-use and wire up my own design.

I'll probably use a potentiometer for my speed control.

 

[Scimmia]

If you're using a metal case (such as the computer case or the power supply case), someone here accomplished it by cutting a hole where the magnet is. Seemed to work out great.

McKBrew, a pot won't usually be able to take the full current through it, it's more for signal level control. People here using pots are using them to control a voltage regulator. You'll want a rheostat that's rated to take the heat if you're just going to use it alone.

 

[HenryHill]

-Never mind-

 

[Seabee John]

Considering I'm short on funds but making one of these would be cool... what's the issue with using a old power supply from a computer to go ahead and run the fan? I know I may have to put some resistors in to lower the speed but just wondering....

Would be sweet to just mod my old desktop tower that I don't use and put the fan/magnet combo right under the top of it so I could set a flask right on top and just turn the computer on and let it run hmm... thoughts?

search "bare bones stirplate" for an economical simple controller