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

[backdeckbrewery]

I have some small rare earth magnets.... I might pull the hd magnet i have on there now off and try the smaller disc magnets..... I think I have 8 of those..... should be enough..... I will fill you in if it works.

Thanks again!

 

[Homercidal]

I bought a prebuilt PWM circuit to control my BK heater. The real purpose of this thing is DC motor control. So I tested on a computer fan and it works amazingly well. It would be the right thing to use to control the speed of a stirplate.

The circuit only cost about $15 after shipping, which is twice the price of the circuit itself. Although I am getting by with the simple POT for s dial now, I may switch to this other thing. It only took about 1/2 hour to solder up a few components.

It will turn the fan from almost nothing (well, a complete stop. but there is a point where it will only turn so slow before stopping) and full speed and anywhere in between.

 

[Burton76]

the motor is as close as it can get.... it ticks the top of the box just a little.... I have a feeling that it might be spinning too fast... I have a 12v powersupply with a pot inline..... it is turned all the way down..... I was thinking of adding another magnet possibly and see if that works or maybe switching to a lower power supply...... I tried a 2 in bar as well and it throws that too...... it is just strange that both bars work just fine in the 1L flask but not the 2L.......I also wonder if thickness of the liquid will make a difference too.... it seems when I have yeast in there not just water it spins slower..... which makes sense.....I will keep playing with it.... just wondered if anyone else has had the same experience.... Thanks for the advice

I'm also having the same problem. I'm also using a 12v powersupply, 2L flask and 2 HD magnets. The bar will get thrown even with the speed turned down to the lowest setting. I was going to add another magnet or two tonight. If that didn't work I was going to change out the power supply for one with a lower voltage.

 

[Flomaster]

the small button magnets I scored at ace hardware in post number 492 are extremely strong. I'll be using two per side, but I could actually use 3 if need be.

call your local hardware store and see what they have. Big Box store like Lowes or Home Depot didn't have a good selection of magnets.

-=Jason=-

 

[backdeckbrewery]

She's a spinning now..... I ended up taking 1 HD magnet off and adding 4 small disc magnets and it works great....I still might end up swapping out the power supply because even at the lowest speed it sucks the vortex to the bottom making a gurgling sound..... I have a feeling it wont do that when there is yeast in there because the viscosity of the liquid will be much higher causing it to spin slower..... I am just happy it is working.

 

[rack04]

Can there be "too much" stirring action? My stir plate is set on the slowest setting and there is significant movement in the glass.

 

[Snafu]

Just finished up this project last night, it seems to work great although I think its under powered. When I turn it up on high I get about a 2" vortex and thats with just water. I think the cell charger I was using is 6vdc, but I just found another one thats 9vdc I'll try that tonight. But other than that, this is a great cheap and easy project. PROST! So easy a caveman could do it.

 

[Snafu]

So here's what I got. Cellphone charger via the pot, varies 3vdc to 5vdc. So maxed out I get about
11/2 inch vortex with water. I just tried a 9vdc it goes from 7-9 vdc on the pot. But even at 7 vdc (minimum ) it throws the stir bar. So I guess I'll try the smaller one first, and if need be due to viscosity , I can move up to the 9vdc one.

 

[paull390]

I am trying to build this stir plate. I bought the parts at Radio Shack and pulled a fan out of an old computer. The rheostat slows the fan down but it still spins much faster than necessary and more than the stir bar can take. Any suggestions to slow the fan speed more?
Thanks!

 

[dragonlor20]

I am trying to build this stir plate. I bought the parts at Radio Shack and pulled a fan out of an old computer. The rheostat slows the fan down but it still spins much faster than necessary and more than the stir bar can take. Any suggestions to slow the fan speed more?
Thanks!

You can limit the electricity going into the stirplate. Cheaper cellphone chargers (think 10 dollar prepaid phones) have lower electricity levels. Otherwise, you may want to look at how big your stirbar is. I have a small one that works really well, but my 2 inch one won't hold onto my magnet configuration... So there's that.

 

[Cstgrd1]

I used an Xbox 360 for my stirplate


http://i1100.photobucket.com/albums/g401/Cstgrd1/My New Stirplate/Stirplate2.jpg

 

[Kayos]

I used an Xbox 360 for my stirplate


http://i1100.photobucket.com/albums/g401/Cstgrd1/My New Stirplate/Stirplate2.jpg

Airlock off, buddy....you need O2 exchange

 

[Kayos]

I am trying to build this stir plate. I bought the parts at Radio Shack and pulled a fan out of an old computer. The rheostat slows the fan down but it still spins much faster than necessary and more than the stir bar can take. Any suggestions to slow the fan speed more?
Thanks!

I thought the same thing, but the wort was much thicker than water. With wort in there, it's good!

Get the stir bar to not get thrown by making the magnet closer to the top of the box.

 

[Cstgrd1]

What do you do when it starts offgassing(sp?) Co2?

 

[Cstgrd1]

Airlock off, buddy....you need O2 exchange

Sorry, new to this...What do you do when it starts offgassing(sp?) Co2?

 

[redde2brew]

I built a stir plate and made my first starter today. I had so much foam I need a blow off tube for a 2000ml flask. Normally I only have a few inches of foam in flask, it seems to really made a difference.

 

[Cstgrd1]

I was going to use one for my next starter as i had to carefully adjust the speed to keep the foam to a minimum(i still had to clean the airlock twice)...If there is Co2 in the beaker then how would oxygen get to the yeast after fermentation began anyhow?

 

[camiller]

I was going to use one for my next starter as i had to carefully adjust the speed to keep the foam to a minimum(i still had to clean the airlock twice)...If there is Co2 in the beaker then how would oxygen get to the yeast after fermentation began anyhow?

Because it is being stirred the head space is not a stable place for co2 to form a layer but rather a turbulent place that remains in motion due to the friction between the moving liquid and the air in the head space. Loosely capping the flask with foil (or using an autoclavable foam stopper) will allow air exchange but prevent contaminates from getting in. Remember bugs don't fall up!

 

[rekoob]

+1 the main reason for the stir plate is to aerate and allow the yeast to grow (multiply) faster.

EDIT: maybe faster isn't the right word...

 

[rekoob]

I used an Xbox 360 for my stirplate


http://i1100.photobucket.com/albums/g401/Cstgrd1/My New Stirplate/Stirplate2.jpg

LOVE the xBox....

 

[bobz]

The stir plate should be loosely covered for air movement. I use a aquarium pump to provide oxygen to the propagation process inside the flask covered with a sandwich baggy.
Bad things fall don't crawl up. I try to stay under the crabtree effect. There is a great deal of understanding to be acquired. Google aerobic yeast propagation.
bobz

 

[Snafu]

Just finished mine up

 

[Cstgrd1]

Ty all for the info. And to think I was just showing off my stirplate. Good times. Cheers :Mug

 

[Kayos]

Sorry, new to this...What do you do when it starts offgassing(sp?) Co2?

It needs O2 - that's the point of the stirplate, O2 exchange and suspension. Just cover loosely with some foil (preferably sanitized - just spray some on) and let it do it's thing.

 

[StoneFan]

So I stopped by radio shack today and picked up this guy:

http://www.radioshack.com/product/index.jsp?productId=3012598

I got it to turn off and on by the push button......but I don't have any control over speed

I wired it up basically like a regular pot. The two tabs on top didn't do anything with my continuity tester. The middle of the three seemed to be the constant. The outer two toggled with the pushbutton.

Any ideas?

 

[cms]

Just saw a youtube video this morning and felt inspired. Made this while my kids were napping...

(https://picasaweb.google.com/lh/photo/UHIbmBqL90YohizqQMLjOXgWzBLAmVYM23lJu_h_3KY?feat=directlink)
The box and the fan came out of an old Shuttle PC that was in the trunk of my car for the last year waiting to be recycled. I had a dead hard drive that I yanked the magnet from. I had a spare on/off button from a previous project. The DC9V power adapter was from a box of old adapters (I'm a pack rat for that sort of stuff) - I think it used to be for an answering machine. The magnet is nearly flush with the top of the case so I could either shim between the fan and the tabs on the box to lower it, or (what I'll end up doing) get some rubber pads for each screw location so the vessel I'm stirring will be less likely to slide around.

I didn't bother balancing the washer (eyeballed and CA glued to the fan blade) since I figured I could just balance the magnet later. I would do that differently next time since the magnet sort of self-centers on the washer. In the end, I was able to balance it reasonably well in a few tries.

I don't have a flask or stir bar to test it out with but I figure it will work pretty well. If I need to add a pot for speed control, then I will probably have to buy one. I also have another power adapter in my box that is one of those universal numbers. So I could use the voltage settings as the speed control.

Total cost: Free!

 

[Daniel82]

I've used a 5.7v, 10v, and 12v power supply to see which one works the best. The 5.7v works but only gets a inch dimple or so for a vortex. The 12v throws the bar immediately. The 10v spins for a few seconds before it throws the bar.

The bar is 2 x 3/8. I think its probably too large but its the only one I have and they are expensive since the shipping on them is alot and I don't want to pay another $17 to see if it fixes the problem.

Any suggestions on what to do to perhaps make the 10v work or should I just settle on the 5.7v.

 

[TripleHopped]

I've used a 5.7v, 10v, and 12v power supply to see which one works the best. The 5.7v works but only gets a inch dimple or so for a vortex. The 12v throws the bar immediately. The 10v spins for a few seconds before it throws the bar.

The bar is 2 x 3/8. I think its probably too large but its the only one I have and they are expensive since the shipping on them is alot and I don't want to pay another $17 to see if it fixes the problem.

Any suggestions on what to do to perhaps make the 10v work or should I just settle on the 5.7v.

Use the 5.7v. All you need is the yeast to stay up in suspension.

 

[Daniel82]

Ok I will the vortex just looks so cool though

 

[butler1244]

Ok I will the vortex just looks so cool though

I thought the same thing and didn't want to settle for the 9v since the vortex harldly came down an inch. I just stacked two hard drive magnets and went with a 12v...the vortex hits bottom now