Bare Bones Stirplate

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Seabee John

Swing the BIG hammer
HBT Supporter
Joined
Oct 1, 2007
Messages
2,309
Reaction score
71
Location
Sunrise
13248-CBJohnplate14.jpg


Here it is! Thanks to all the folks who shared their intellectual labor.

I didn't have the knowledge do put together a stir plate from parts at Radio Shack... but I did have a hobby in a past life that provided the answer: The old model railroad transformer works well as a rheostat.

13248-CBJohnplate13.jpg


I also lacked the nice plastic box in pretty colors so I went basic: I just cut out the center of the fan guard (so it wouldn't interfere with the magnets) and that serves as the platform for the beaker

13248-CBJohnplate12.jpg


Since I went cheap on everything else, I figured why stop there: I used a wide mouth glass bottle (1 pint / 473 ml) as my beaker. It may not be able to produce a batch as large as the 1000 ml beaker, but it gets the job done. It also accepts the airlock stopper just fine.

13248-CBJohnplate11.jpg


So what do you all think?
 
BRILLIANT!

That fan guard is AWESOME! I have been looking for an enclosure for mine and you have given me an idea!

Good work!
 
I don't know if there is any vibration at all with this rig, but I'd probably dip the feet in the stuff they make to dip tool handles in and paint some on the fan grill as well just to keep things from sliding around when you turn your back on it.
 
So let me get this straight. Parts list as follows...

Electric train transformer
Fan
Fan guard
magnets

am I missing much?

The train transformer plugs into the wall so no goofing with electronics. Did you have to add a resistor anywhere or just wire the fan up directly up to the transformer?
 
Grimsawyer said:
So let me get this straight. Parts list as follows...

Electric train transformer
Fan
Fan guard
magnets

am I missing much?

The train transformer plugs into the wall so no goofing with electronics. Did you have to add a resistor anywhere or just wire the fan up directly up to the transformer?


That's just about it. The fan guard was on the fan when I pulled it out of the computer. I snipped the inner rings out because they interfered with the magnets. I just wired it up to the DC side of my transformer and set it on a lower speed. Works like a charm!

I also added some machine screws for legs to keep the fan off the surface for air flow. No ther parts were added
 
Nice. :)

It looks as if I'm about 1 part shy of getting that setup. :p I need a grill guard. I'm a PC nut, so I'm able to get them rather easily but I don't have any in my box of goodies.

Great idea!

What are you using as a stir bar?
 
Am I insane, or would something like this work, and let you have a variable-speed control on your stirplate?

mrcaa300.jpg


If so, anyone got an old computer fan and some magnets they'd trade for some homebrew?
 
I have a bunch of grill guards laying around.

Check your PM.

Kevin Dean said:
Nice. :)

It looks as if I'm about 1 part shy of getting that setup. :p I need a grill guard. I'm a PC nut, so I'm able to get them rather easily but I don't have any in my box of goodies.

Great idea!

What are you using as a stir bar?
 
the_bird said:
Am I insane, or would something like this work, and let you have a variable-speed control on your stirplate?

mrcaa300.jpg


If so, anyone got an old computer fan and some magnets they'd trade for some homebrew?

That's it... should work fine. I found that my fan will only run with one polarity... (forward / reverse switch has to be in forward) And just make sure you hook up your fan wires to the DC side of the transformer.
 
looks nice, only thing I'd be worried about is gettin' the fan wet. I think I'd still invest in a project box for water/wort protection.
 
Just a little bit of safety warning. Make sue that whatever transformer/powerpack you use is a DC powerpack. Normally a DC transformer is called a powerpack and an AC transformer is called just that, a transformer. A powerpack has a transformer in it but it also has a rectifier which turns the AC into DC. Those computer fans are DC powered and AC current will burn out the motors. A DC powerpack has a variable controlled DC circuit while the accessorie circuit is AC. Some of you may have some old Lionel or Amerocan Flyer transformers, these willl not operate the fans without a rectifier in the circuit. So if any of you plan on building one of these and are going to buy a power supply, make sue it is a DC power supply, better known as a powerpack.
 
trainfever said:
Just a little bit of safety warning. Make sue that whatever transformer/powerpack you use is a DC powerpack. Normally a DC transformer is called a powerpack and an AC transformer is called just that, a transformer. A powerpack has a transformer in it but it also has a rectifier which turns the AC into DC. Those computer fans are DC powered and AC current will burn out the motors. A DC powerpack has a variable controlled DC circuit while the accessorie circuit is AC. Some of you may have some old Lionel or Amerocan Flyer transformers, these willl not operate the fans without a rectifier in the circuit. So if any of you plan on building one of these and are going to buy a power supply, make sue it is a DC power supply, better known as a powerpack.



Seabee John said:
And just make sure you hook up your fan wires to the DC side of the transformer.

If it's got a DC side you should be fine.
 
eddie said:
How large of a starter have you done using this set-up?

Seabee John said:
Since I went cheap on everything else, I figured why stop there: I used a wide mouth glass bottle (1 pint / 473 ml) as my beaker. It may not be able to produce a batch as large as the 1000 ml beaker, but it gets the job done. It also accepts the airlock stopper just fine.

I'm sure you could run with a 1000 ml beaker without any problems.
 
I was just curious if you had tried with anything larger yet. I looks interesting and very affordable to build. I plan on trying this in the near future.
 
What kind of glues will work to stick the magnets to the fan anyways? And should the magnets be glued to the center of the fan or on the fins?(I am assuming the center though I am wrong alot. =P) And could I walk into Radioshack and just buy any powerpack or do just certain ones have a "variable controlled DC circuit "?
 
Grimsawyer said:
What kind of glues will work to stick the magnets to the fan anyways? And should the magnets be glued to the center of the fan or on the fins?(I am assuming the center though I am wrong alot. =P) And could I walk into Radioshack and just buy any powerpack or do just certain ones have a "variable controlled DC circuit "?

You can find a hot glue gun at the depot (or if your cheap like me, I just used a hot glue stick with a bic lighter.

Glue them in the center - this is important. If you are off center with your magnets, it will cause a vibration or even worse it will constantly "throw" the stir bar.

Here's the deal on the DC "power pack." Much has changed since I had model trains. These days they power the track with a constant DC voltage and send a digital signal to the microchip in the train on the track. When I was into it, each track had it's own separate power source. The rheostat controlled how fast the train went. That is the style of power pack you want. They should be incredibly cheap. Talk to a guy at a hobby shop. I doubt radio shack would have them...seems like all they carry is cell phone crap.
 
I'm interested in building one of these. Couldn't I just mount the fan to the inside of this: http://www.radioshack.com/product/index.jsp?productId=2062284 and put the beaker on top of the box???

What needs to be understood here is that I'm pretty much clueless when it comes to the science of electronics.

Also, if you don't have a hard drive to spare, where do you get the magnets???
 
Thanks for posting this. The only thing I am missing from my stirplate was the transformer and I had noticed that train transformers looked very similar to what I needed. Since I am clueless, it is good to have a confirmation.

Off to a hobby shop this weekend.
 
ejdischer said:
I'm interested in building one of these. Couldn't I just mount the fan to the inside of this: http://www.radioshack.com/product/index.jsp?productId=2062284 and put the beaker on top of the box???

What needs to be understood here is that I'm pretty much clueless when it comes to the science of electronics.

Also, if you don't have a hard drive to spare, where do you get the magnets???

Google "rare earth magnets" and you will find more than a dozen places selling them on line... I think you can even get them on ebay for a few bucks.

As far as mounting the fan inside your project box, that's what most guys do. Yuri has a great set up if you want to get fancy.

https://www.homebrewtalk.com/showthread.php?t=8850
 
Bit of an update here,... I started doing a bit more reading on starters. Come to find out I need about twice as much starter than I can produce (I put out 400 ml / batch)

Has anyone split a starter between to flasks and alternated them on the stirplate? I'm thinking 24 hrs on original then split the batch into two 400 ml batches and give em 8 hrs on 8 hrs off?

Am I risking to much infection?
 
As long as everything is nice and clean and you keep an airlock on the flask while it's off the stirplate you should be able to make it work. I'd be a little concerned about not getting O2 and the yeast going anaerobic more than infection.

Any reason you can't just get a flask twice the size of your current flask? Also, since you have such an inexpensive stirplate why not just make another?
 
You can get a 1 gal jug from your LHBS for about $5.00. heck of a lot cheaper than an Erlenmeyer flask. The only drawback is that you can't boil your starter wort in it.
 
dantodd said:
As long as everything is nice and clean and you keep an airlock on the flask while it's off the stirplate you should be able to make it work. I'd be a little concerned about not getting O2 and the yeast going anaerobic more than infection.

Any reason you can't just get a flask twice the size of your current flask? Also, since you have such an inexpensive stirplate why not just make another?

That's pretty much what I resigned myself to... I'll make up another.
 
I'm totally making one of these. My brother in law just gave me a bum computer and I'm gonna gut it for the parts. Question though...I've never made a starter but have read about it. How long do you leave it on the stir plate? Should you oxiginate it?
 
jmsullivan: probably would require some internal re-wiring, and is probably costing you too much to begin with to boot :p.

Trodd: how long is a matter of method; many people wait 6-8 hrs. for the activity to maximize and then pitch the whole thing. Others (like me) fear the oxygenated wort, so we let it ferment out over 24 hrs, then put in the fridge for 30 minutes before decanting off the wort and pitching the slurry.
 
Trodd said:
How long do you leave it on the stir plate? Should you oxiginate it?

24 hours should allow the yeast to consume just about all the sugar in reproduction. Assuming you are pitching a tube/smack pack into 1-2 liters or 1.040 wort.

The whole point of the stirplate is oxygenate the wort and keep the yeast in suspension. Keeping the wort oxygenated is critical because when there is O2 available the yeast will reproduce, once the O2 is consumed the yeast will begin creating alcohol.
 
Ok, I got my fan, and I snagged 2 old model train controllers which has speed control and direction control. (an old Tyco model). The only issue is that the fan is 12VDC (I think, all computer fans are 12VDC) and the output on teh controller is 18VDC and 16VDC. I'm a ME not a EE, so does anyone out there know what I need to drop the voltage down to 12VEC? Is it a simple resistor or should I just get a 12VDC supply from a model shop?
 
Trodd said:
Ok, I got my fan, and I snagged 2 old model train controllers which has speed control and direction control. (an old Tyco model). The only issue is that the fan is 12VDC (I think, all computer fans are 12VDC) and the output on teh controller is 18VDC and 16VDC. I'm a ME not a EE, so does anyone out there know what I need to drop the voltage down to 12VEC? Is it a simple resistor or should I just get a 12VDC supply from a model shop?

Ok, here's the cool part. since it's a rheostat, you should be able to hook it up to either. zero on the control means zero voltage. move it up, and so goes the voltage. Now here's the tricky part. Hooking it (your fan) up to an 18 volt controller may fry (probably not) your fan motor. It most certainly will throw your stir bar. I've got a 6 Volt DC controller hooked up to a 12 volt fan and I get to about 25% and I toss the stir bar. Some of the other folks with vastly larger brains than I have may be able to direct you down better more productive paths than I on the disparity of voltages.
good luck!
 
I built another bare bones stir plate. This one is a double barrel 2000 ml bohemouth. I was using 500 ml starters which worked well, but I wanted to improve two things: 1. I wanted to be able to boil in the flask 2. I wanted to reduce the "tinking" noise I was getting from the jars I was using before. I went to midwest and ended up buying the 1000 ml flasks. So here's my question... what's the largest starter per 5 gal batch that you would pitch? I figured I'd pitch into two batches (1000 ml per batch) but would it hurt to pitch 2000 ml for a 5 gal batch? let me know what you think...

here's the photo:

Bare Bones 3.1

barebones3_1.JPG


side note: if you power two fans with one power source, make sure you buy two of the same fan. the one on the left is actually stirring... but at a much slower rate.
 
OCB tilly said:
so...why the stirplate?

For those of us out there that like to make a yeast starter, (there are a few different reasons for this - a simple search will get you a wealth of information) you start out with a small amount of yeast, and pitch it into a "mini brew" of DME, water, and a nutrient - I like Go-Firm myself. Anyway, once you have your starter pitched, you want the yeast to ferment (grow) as much as possible. A stir plate aids this process by a. keeping the yeast suspended in the wort & b. oxygenating the yeast continually.

So say by the Wednesday before a Saturday brew, I pitch a starter of 1 LTR for a 5 gal batch. 1 ltr of yeast starter will reduce the time it takes for the fermentation of your beer. If you start out with a small amount of yeast, it takes a long time for the yeast to multiply enough to properly ferment your beer.
 
Back
Top