# Diy Computer-fan Stir-plate Build



## Wolfy

The epic 36page 6-year-old 'Tight Arse Stir Plate' thread has some great ideas, but with so much information it might appear that making your own stir-plate look more difficult than it is.
These are the DIY Computer-fan Stir-plate assembly instructions that work well for me, and (I hope) are easy for everyone to follow.

The first stir-plate I built this way has been in use for the last 2 years, and is still going fine, the two updated versions work without problem with starters ranging from 50ml to 4L.

Total cost is about the same as that of a pack of liquid-yeast.

*Equipment *(_see next post for alternate suggestions_):





120mm speed-controlled Computer fan, "Scythe 120mm Blue LED with VR Fan (SY1225SL12VBL)".
12V DC power adapter, (cheap) from Ebay.
8x 8mmx1mm rare-earth magnets, same as the cheapest ones on Ebay when searching for 'rare earth magnets'.
A standard (cylindrical) teflon-coated stir-bar (from lab-supply shop), 20mm and 26mm long ones work well for this set-up.
An enclosure, screws etc to mount the fan/stir-plate.
Superglue to stick the magnets to the fan-hub.

*Optional*:
On/off switch.
Solder, a few bits of wire, gaffer-tape, electrical tape, heat-shrink-stuff.

The good thing about the 'speed controlled' Computer fan is that it comes with its own adjustable speed-control knob, so you don't have to worry about adding that yourself:





The tricky part of the stir-plate assembly seems to be getting the magnets positioned correctly.
I use 8 of the 8mm x 1mm round rare-earth magnets, with 2 stacks of 2 on each side of the fan-hub, as per the picture below.
This size and arrangement works well with the fan-hub, and stirs well on all flat-bottomed starter-containers that I have tried.





Attach the magnets with super-glue, but some care and attention is needed, since they will 'interact' with the copper coils inside the fan and once you have placed one, all the others want to try to stick onto them. Draw a line across the middle of the fan-hub and then arrange the magnets along that line. Try to space them evenly since that will help keep the fan balanced (try to do a better job than I did here, also try not to stick your fingers together or to the magnets or fan with the superglue).

If you buy your stir-bar before you place the magnets, I have found that the best spacing for the magnets is to have them as wide apart as the stir-bar is long (as per the picture below), closer or further apart does not work as well, but the distance is dependent on the length of your stir-bar.
By using 2 sets of magnets, both a smaller and larger stir-bar can be used.





To assemble the stir-plate, cut the plugs from the power-adapter and the fan, and then strip the wires.
Connect the appropriate wires (positive/negative, usually red/black) from the power supply to the fan (red and black wires, the yellow wire is not used, so simply cut it off and ignore it).
The connection will be 12V and the fan will only work when they are connected correctly, so you can easily join the wires together to ensure that it works before you attach them permanently.
Solder and shrink wrap are the best way to go, but the wires can simply be wound together by hand and then wrapped with electrical tape.





An on/off switch allows the stir-plate to be controlled without having to pull the plug from the wall, simply wire the power-supply wire(s) to one of the switch's terminal(s), and the fan-wire(s) to the other.

Now all you need to do is to mount the fan/stir-plate in an enclosure (see below for more info).


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## Wolfy

There are many variations of equipment that all work much the same way, you might already have most of the items, and so any additional costs will be minimal, read through the Tight Arse Stir Plate thread if you want more info.

Any size computer-fan will work, however I find the 120mm fans are easy to work with and the fan-hub is a good size for the size stir-bars that I use.
Most any old computer, or computer power supply will have a fan you can use, simply remove it, strip the wires and use it as outlined above.

(Old) Computer disk-drives have strong magnets inside them that can be removed and glued to the fan-hub, this works fine, but is more effort and since the magnets are a U-type shape with both poles on the same magnet, they are harder to adjust and tend to be a little more uneven. The rare earth magnets are very cheap on Ebay, so I find them a much better solution.

Any 12V DC power supply should work fine, if you have an old (unused) one from a mobile phone, cordless drill or other electrical device, there would not be any need to buy a new one. Computer fans also function from about 5V up to about 15V, so in theory any DC adapter in that range will work, however it will change the speed the fan works at, and may make it too fast or too slow. Old computer power-supplies can also be used, however they tend to be large and cumbersome, but if you have one it is possible to short the on/off leads and use the 12V supply from that to power the stir-plate. It is also possible to use power-adapters used for external computer-hard drives or the like, since they will usually supply 12V, it is just a matter of identifying which wires are which.

If you do not have a 'speed controlled' fan, you can adjust the speed of the fan by altering the voltage, this can be done with a variable power supply or by changing power supply, however I have found that the continuous-dial-type-speed adjustment works much better than the 'steps' that variable power-supplys offer, and that it is much easier to get the stir-plate working correctly if you can fine-tune the fan-speed. A potentiometer is also a good way to control the fan-speed, it just requires a little bit of extra electronics.
A search on Ebay for "LED Dimmer" should result in a number of (different types) of LED Dimmers, used for LED lights, these would also make a very good pre-made speed controller for a DIY stir-plate. Simply wire them in between the power supply and the fan, and they would provide continuous speed-adjustment.

While the teflon stir-bar will not be cheap (for something so small) they are designed for the job and work very well, some people have used various magnetic or metalic items, but especially if you have lab-glassware the additional expense of a real stir-bar is well worth it. They can also be boiled/sterilized when you make your starters simply by dropping them into the starter-flask while it is on the stove. The standard cylinder type stir bars work best and are much more quiet than the strange shaped ones or ones with a pivot in the middle, and if you are going to use the stir-plate in your house, keeping it quiet is good.


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## Wolfy

*Enclosure*.

A quick browse through the pictures in the Tight Arse Stir Plate thread will show that there are many ways to mount the fan/stir-plate.

When mounting the fan, obviously the magnets need to be on the 'top' as close to the top of the enclosure as possible without actually rubbing against it when it spins (make sure you check before turning the fan on).
Solid, thin, non magnetic or metallic materials (usually plastic) work best, but the type of enclosure you use often depends on what materials or skills are at hand.
Nice wooden, plastic or perspex enclosures can be made if you are skilled working with those materials.
Pre-made hobby/jiffy boxes are common, but anything else can also be used, a children's plastic lunch-box, a plastic kitchen-container, a CD spindle, a bucket etc, the list is almost endless.

Try to ensure that the the top of the enclosure is fully covered, yeast-starters can over-flow the container, and drip down and short-out the fan, which is something best avoided (the first stir-plate I made caused some nice fire-works in the lounge room this way).

In this case I used the lid from an old Coopers-type fermentor, since I use cling-wrap when fermenting beer, the lids are essentially rubbish now.
It looks ugly and I hope that others make stir-plate enclosures that look nicer, however it is solid, the fan fits perfectly inside the 'indent', the size makes it impossible to tip over, and it easily holds even a 5L starter.

From below, On/off switch and speed-control at the top, power supply at the bottom of the photo.





And from the top it looks something like this, gaffer tape is ugly but practical and saves scratches on the glassware from the screws, gluing the fan was an option but its nice to have it removable if it needs to be adjusted :





In-action shots (stepping up a lager yeast):





I grow my starters in the lounge-room since that is the most comfortable temperature all year round (Air-cond in summer and heated in winter), but since I live in a normal (maybe a tad messy) house, with a cat, open doors, dust and all that I try to keep the starters covered at all times (when not taking photos):


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## Dazza88

So Wolfy, is that stir bar pictured about 2 cm? What size stir bar is best all rounder for starting off?

Great threads and nice tea towels


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## stl

DazDog said:


> Great threads and nice tea towels



Maybe the wee lil yeasties can learn Welsh while they grow up!


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## Supra-Jim

Very nice work Wolfy. Simple cheap and nicely explained with photos. 

Maybe you should copy this into a PDF file and submit into the articles section.

Cheers SJ


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## Wolfy

DazDog said:


> So Wolfy, is that stir bar pictured about 2 cm? What size stir bar is best all rounder for starting off?


It's in use now, so I can't really measure it, but a stir-bar between 2 and 3cm should work fine, I wouldn't go any smaller or larger than that.


stl said:


> Maybe the wee lil yeasties can learn Welsh while they grow up!


LOL, the in-laws visited the UK last year, and didn't bring me home any beer-stuff so the tea-towels have to do.


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## Wolfy

I can't edit my first post now, but I forgot to add this information about aligning the polarity of the magnets when gluing them to the fan-hub:

The ends of the stir-bar will have opposite magnetic polarity, so each set of 4 magnets (on opposite sides of the fan-hub) must be arranged so that their magnetic polarity is the opposite to the ones on the other side. Essentially one set of magnets 'push up' and on the other side of the fan-hub the magnets 'pull down', this way the corresponding 'opposite' magnetic attraction from the ends of the stir-bar will 'lock on' to the magnets as the fan spins (even at 1600RPM the stir-bar shown in the picture below will stay firmly attached to the magnets).
(If you placed all the magnets the same way up, one side would repel rather than attract one end of the stir-bar.)


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## ben_harvey

Wolfy said:


> While the teflon stir-bar will not be cheap (for something so small) they are designed for the job and work very well, some people have used various magnetic or metalic items, but especially if you have lab-glassware the additional expense of a real stir-bar is well worth it. They can also be boiled/sterilized when you make your starters simply by dropping them into the starter-flask while it is on the stove. The standard cylinder type stir bars work best and are much more quiet than the strange shaped ones or ones with a pivot in the middle, and if you are going to use the stir-plate in your house, keeping it quiet is good.



I was going to post something about the stir bar losing its magnetism when heated, but a quick check on Wikipedia has confirmed no-one should ever even get close to it (look up Curie temperature). Sometimes I like to sterilise with a plasma torch though...  

But seriously, excellent post.


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## Wolfy

A few days later and a good dose of patience to get it working on the decidedly round-bottom 5L glass demijohn:




(ps: Donations of 3, 4 an 5L Erlenmeyer flasks are most welcome).


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## husky

have you got a good online source for the fan and stir bars. I have found the fan on ebay for around $35 delivered and I have fired off an email to Science Supply in Mitcham for the stir bars. Any other options? No spare time during business hours unfortunatly so online stores who post would be handy.


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## Wolfy

husky said:


> have you got a good online source for the fan and stir bars. I have found the fan on ebay for around $35 delivered and I have fired off an email to Science Supply in Mitcham for the stir bars. Any other options? No spare time during business hours unfortunatly so online stores who post would be handy.


SSC is where I got my stir-bars from, however I picked them up rather than having them delivered, there are a few other similar online shops (often the same as supply flasks and test tubes) but I don't have a list of them I'm sorry.

I paid $12ea for the fans, on special at PC Case Gear, if you can't find a cheaper source for the fans (google for the model number) I'd be tempted to use a generic fan and dimmer switch due to the difference in price.


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## Jarthy

i have found 2, 2nd one looks more affordable.

http://www.wiltronics.com.au/catalogue/135...gnetic-stirrers - these guys also stock electrical components for the rest of the stir plate if required.

http://www.proscitech.com.au/cataloguex/on...page=l5#l34-022


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## Wolfy

Jarthy, just be aware that many people who have a stir-bar with a pivot ring (the wiltronics ones) have said how noisy they can be.


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## Jarthy

good to know thanks wolfy


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## felten

I just ordered the magnets, LED dimmer, and stirbar from ebay, ended up getting an egg shaped stir bar instead of a pivot ring. I have plenty of 80mm fans and hopefully I can dig up a 12v phone charger from somewhere.

Thanks for the suggestions.


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## Dazza88

Inspired by the diy stir plate, have received some ebay purchases and have wired a power supply ($3), led dimmer ($7) and fan (old PC) together. It works really well. Just need the magnets, stir bar and flasks to arrive. Haven't considered the housing yet. I want to internalize the dimmer and it's pretty big. 

Didn't bother with the switch (5 for $2 delivered - ebay), the dimmer turns off. 




The connection of the fan to led dimmer is screwed in, will make it easy to swap fans, power supply etc.


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## felten

I bought the same dimmer, pretty nifty. I just mounted the dimmer's box internally, but attached the dial into the wall of my stir plate housing. It comes apart easily and has a nice long cord to the pot.

no pics atm :X


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## Dazza88

Felten, you got details on your housing?


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## Malted

I am trying to get my head around a few things. I am not a sparky or electronically minded. Please tell me how I am going so far:
I know with my stirplate when I have a large volume on top of it (say 2.0L+) at higher gravity (OG say 1.040) it most times doesn't show a whirlpool/vortex, particularly not during krausen but shows after that when it has fermented and the gravity is lower and the yeast is settling out. Perhaps it has to do with the viscosity of the starter (as expressed through specific gravity reading)- fermented is thinner?
So I am thinking grunt is good.

Since I want to build a TASP, this got me to thinking and Googling and thinking some more. 
There has been talk of dimmer switches etc and voltage regulation for speed control. These lower the voltage to lower the speed of the fan but less voltage equals less torque. Lower speed = lower grunt.

PWM (Pulse Width Modulation) seems to me to be the shizzle. You can control the speed of the fan but still retain pretty much 100% of potential torque because they are still at 12 volts. Lower speed = same grunt. (also less heat generated). It seems a lot of computer fans have four pin plugs because there is a PWM function on the computer motherboard = not useful to me. 
There are some schematics for PWM units you can solder up on circuit boards yourself = not my bag baby. 
There are commercially available PWM units for high voltage motors = not useful.
I found a few 12 volt PWM 'kits' but these are for 20 -30 amps (lowest I found was 3A) not 0.3A or so of a computer fan = not useful to me.

Does anyone have a solution for an external PWM for a computer fan?
Have I got it all wrong?
Am I chasing something that doesn't need to be chased?


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## Dazza88

Malted, i wouldn't know either but what about a pc fan controller?


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## Malted

DazDog said:


> Malted, i wouldn't know either but what about a pc fan controller?



As far as I can tell they are not PWM's, they just dial down the voltage. Lower voltage = lower grunt?
A PWM keeps it at 12 volts but switches on and off very rapidly (like 30 times a second) to regulate the speed. Thus when it is on it's got the 12volt grunt.


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## Wolfy

Malted, make sure you read through the Tight Arse Stir Plate thread - if you have not already - there are many different comments/suggestions/options there. All I was really trying to do here is to make the process of building a workable stir-plate as cheap and easy as possible for anyone who can connect a couple of wires together.

Personally - if you plan to continue using a computer-fan based stir-plate - I think you are over-analyzing things, these things are designed to spin under virtually no load and push air, so worrying about PWM, torque and all that is simply over-kill. For stirring larger volumes, increase the stir-bar size or increase the fan speed, and I think you'd do as much or more as using a PWM solution (if you were sill using a computer fan).

Stirring the starter is mostly about 3 things: introducing oxygen, degassing CO2 and keeping the yeast in suspension, so even if the stir-plate does not have a noticeable vortex at larger volumes - but is still mixing the starter well, it should still be doing all those things.


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## Malted

Wolfy said:


> Malted, make sure you read through the Tight Arse Stir Plate thread - if you have not already - there are many different comments/suggestions/options there.
> All I was really trying to do here is to make the process of building a workable stir-plate as cheap and easy as possible for anyone who can connect a couple of wires together. *Yes you certainly have achieved that, sorry for sullying it.
> *
> Personally - if you plan to continue using a computer-fan based stir-plate - I think you are *over-analyzing* things, these things are designed to spin under virtually no load and push air, so worrying about PWM, torque and all that is simply *over-kill*. For stirring larger volumes, increase the stir-bar size or increase the fan speed, and I think you'd do as much or more as using a PWM solution (if you were sill using a computer fan). *This answers my questions.
> *
> Stirring the starter is mostly about 3 things: introducing oxygen, degassing CO2 and keeping the yeast in suspension, so even if the stir-plate does not have a noticeable vortex at larger volumes - but is still mixing the starter well, it should still be doing all those things.



G'day Wolfy, sorry mate, I wasn't knocking you. I was just trying to clear my head. Thank you for the answers. 
I am genuinely happy to retract (delete) my post from here if you like (to clean it up). Let me know.


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## felten

DazDog said:


> Felten, you got details on your housing?


It's a big Tupperware container 

Those LED dimmers linked a few posts up are PWM controllers, at least it says "PWM digital dimming" on the pamphlet that came with it.


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## Wolfy

Malted said:


> G'day Wolfy, sorry mate, I wasn't knocking you. I was just trying to clear my head. Thank you for the answers.
> I am genuinely happy to retract (delete) my post from here if you like (to clean it up). Let me know.


No offense was taken, and I've no idea if my theory is correct or not - it may well be that I'm not right - but was just posting my (uneducated) thoughts on the subject.


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## a1149913

Hi, just wondering what the specs of your power supply are. I'm making a stir plate and i'm using an old nokia phone charger but it doesnt seem to power the fan enough. It doesnt ever reach maximum speed (even without the stir bar) and will most of the time struggle to get going.

Thanks, Jacob


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## Wolfy

Computer fans are rated at 12V (but they usually operate from 6-15V, just at different speeds depending on the voltage).
Last time I looked at a Nokia charger it was less than 12V.


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## ben_harvey

From memory I think that Nokia (or other phone chargers) are around 5V, give or take.
They probably have pitiful output current as well.

Keep in mind that at low voltage you need more current to supply the same power (power = volts x amps) so a 6 watt (just picking a number out of my head) fan would draw half an amp if it was designed to run at 12 volts but it would draw 1 amp if it was designed to run at 6 volts. The designed-for-12 V fan would have a resistance of 24 ohms and the designed-for-6 V fan, 6 ohms.

These figures don't apply if you're running a fan designed for 12 V at 6 V, as the current drops proportionally to the voltage, however I think that power drops with the square of the voltage applied (i.e. half voltage = 1/4 power). This would explain why the phone charger has issues running the fan, it's supplying half the voltage but really it only supplies a quarter of the power. Theoretically the fan should run at a quarter speed but it can't overcome friction to get started.

Clear as mud?

I'm not a sparky or anything, but I guarantee* this information is correct at the time of writing.


*not a guarantee


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## Amber Fluid

The mobile phone charger I have runs at 3.5v and has no problem starting up and maintaining an adequate speed to push air around. I say the proof is in the pudding and therefore, I don't know about your theory, but it certainly does not apply in my case.

After a bit of research on this forum as well, I can't recall anyone else having issues with their fans starting up either. However, I really shouldn't be speaking for other people, just stating what I have read here.


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## Wolfy

batman said:


> Clear as mud?


Yep, clear as mud.

The fans I used in the OP are 12V 0.3Amp so you can put that into whatever formula you like, but in general they work fine at a wide range of voltages.


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## ben_harvey

Ok fair enough then. I was under the impression the low voltage charges were a bit useless. I'm not speaking from experience here as I haven't built one of these things yet, but I plan to as soon as I get back from site.
I just found out a guy from work brews beer and he highly recommends liquid yeast (he still uses kits though! He gets his cultures from a microbiologist in Perth) so I can't wait to give it a shot.
It's just so expensive, hence 'll try and make a few cultures and see how I go.

Thanks again for the post Wolfy.


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## tones0606

Just waiting on magnets and stir plate.
Will post some pics hopefully in the next few days.
So simple to build.
Cheers


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## bear09

Hi All,

Just wanted to add some pix of my attempt at this stir plate. Note that I used the original container from a stir plate that I previously purchased from the US (http://www.aussiehomebrewer.com/forum/index.php?showtopic=53670). The variable resistor on the one from the US stopped working - it was either on or off - no in between. Also, I was never happy with its top speed - it could never vortex all the way to the bar like some you tube examples I had found.

Anyhow I followed the instructions on this post and after 2 hours of adjusting the height clearance (no kidding thats how long it took me to get it to balance) this was the result...

Im really happy with it. Spins bloody fast and the variable resistor has an awesome range from no to full on go.

Give it a go yourself. CHEERS for the help!!


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## Charst

looks good, I'm planning on getting mine finished this weekend, turns pretty well just finishing the top, can anyone give me any advice on getting it to spin quieter? sounds like a marble rattling around in there.


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## Acasta

Not that this tutorial isn't easy enough to follow! But heres a video I found doing this project. Looks so easy. http://youtu.be/XVLB9c0j1iU


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## felten

I was waiting for him to cut himself :X

I managed to bury most of my pocket knifes small blade into my thumb while making mine.


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## beerdrinkingbob

not sure why he didn't use the pliers to strip the wires, the blade looks a bit dangerous.

Thanks for the link acasta, brings it all together


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## bear09

Charst said:


> looks good, I'm planning on getting mine finished this weekend, turns pretty well just finishing the top, can anyone give me any advice on getting it to spin quieter? sounds like a marble rattling around in there.



Adjust the height clearance.... Like I said above, I literally spent 2 hours doing this. I didnt think there would be much in this but .5 of a mm made a difference. Also making sure the fan was level helped too. I finall found the sweet spot where the fan has maximum rpm and the bar makes a little noise only every 30 sec or so.


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## davo4772

Stir bars on fleabay.

Ordered a 27mm for A$5.75. Free postage


Here

No great loss if it turns out to be rubbish.


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## Newbee(r)

Just finished mine. Pretty happy with it - a bit of fiddling around with the magnets, had 8 x 3 mm so only needed two and its going great guns. Thanks again for the DIY instructions.


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## davo4772

Wolfy said:


> A few days later and a good dose of patience to get it working on the decidedly round-bottom 5L glass demijohn:
> 
> 
> 
> 
> (ps: Donations of 3, 4 an 5L Erlenmeyer flasks are most welcome).




Hey Wolfy,

I have the same 5L glass demijohn. What adjustments did you make in order for it to work with the concave bottom?
5L erlenmeyers are a bit expensive.

Cheers


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## benno1973

Quick question, maybe it's already been asked but I can't see it in this thread, and it's been a while since I read the Tight Arse Stir Plate thread, so here goes...

I see lots of people using LED dimmers in these projects, 12V 0-8A. As most of the fans we're using are around 0.3A, doesn't that mean that the max draw by the fan is 0.3A? So how does a 0-8A dimmer work? I assume that it adjusts the amps between 0 when the dial is at minimum, and 8A when the dial is at max? So wouldn't the fan be at max speed after turning the dial just to the right a little?

Obviously I haven't used one myself, so I don't know. And I know nothing about electronics, that's probably obvious.


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## pyrosx

Kaiser Soze said:


> Quick question, maybe it's already been asked but I can't see it in this thread, and it's been a while since I read the Tight Arse Stir Plate thread, so here goes...
> 
> I see lots of people using LED dimmers in these projects, 12V 0-8A. As most of the fans we're using are around 0.3A, doesn't that mean that the max draw by the fan is 0.3A? So how does a 0-8A dimmer work? I assume that it adjusts the amps between 0 when the dial is at minimum, and 8A when the dial is at max? So wouldn't the fan be at max speed after turning the dial just to the right a little?
> 
> Obviously I haven't used one myself, so I don't know. And I know nothing about electronics, that's probably obvious.



0-8 amps? 8 amps is a LOT. Without knowing exactly what im talking about (in that i cant find an actual link to said LED dimmer specs), i'm still fairly confident in saying you've got something a bit wrong there. 10 amps is the max draw of most household wiring. An LED drawing 8amp would be like a personal sun?


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## benno1973

These are the dimmers. They specify output power 96W, output current 8A. I assume that they are for a bunch of LED lights, not just a single light. Still, as you point out, LED lights draw bugger all, so I'm not sure how these work exactly...


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## Wolfy

david72 said:


> I have the same 5L glass demijohn. What adjustments did you make in order for it to work with the concave bottom?


Lots of patience and trial-and-error.
Each of my demi-johns have a circular flat area (from how they are made I think) so it's just a matter of being super patient (and trying 100 times) to get the stir-bar balanced.


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## Dazza88

Kaiser Soze said:


> These are the dimmers. They specify output power 96W, output current 8A. I assume that they are for a bunch of LED lights, not just a single light. Still, as you point out, LED lights draw bugger all, so I'm not sure how these work exactly...




They are pretty cheap. About half way on the dial is the fastest I get get a stirrer to spin. And lower produces a slightly slower spin so you do have some control with it.


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## Fents

can anyone point me to a site that i can buy the exact rare earth magnets and a stir bar i need pls, i cant be assed to trawl through 50 pages. shanks.


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## argon

equally i can't be arsed searching for you


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## Dazza88

Search on ebay.


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## Supra-Jim

ebay

Stir bars


Rare Earth Magnets 

Cheers SJ


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## DU99

aussie magnet in richmond,ring http://www.ssapl.com.au/ about stirrer bar's if you in a hurry also they sell flask's ebay is where i got my stir bar from..


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## Gar

argon said:


> equally i can't be arsed searching for you



Your in a helpful mood lately argon :lol: 

Here you go fents http://www.rareearth.com.au/magnets


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## argon

Gar said:


> Your in a helpful mood lately argon :lol:
> 
> Here you go fents http://www.rareearth.com.au/magnets



I don't mind helping... but when someone just states...


Fents said:


> i cant be assed to trawl through 50 pages.


It's hard to be helpful to those that won't help themselves



As an example;



Some bloke who did a bit of research said:


> I had read through the thread and a quick search around the internets for some decent magnets. Anyone got any recommendations for somewhere i can get magnets that would be best to use.



Yeah sure here you go;

http://www.rareearth.com.au/magnets


Edit: ahhhh... nice link!!... just got it. :lol: :lol:


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## Silo Ted

Argon, what does the word Diy mean in the title of this thread? I cant be arsed opening a new browser window.


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## Fents

thanks du99, rang SSL. only problem is i have no idea what size magnets or stir bar....guess i'll have a search hey argon?


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## Fents

argon said:


> I don't mind helping... but when someone just states...
> It's hard to be helpful to those that won't help themselves



for your info i did the ahb google search, came up with this thread looked through and didnt see it


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## Silo Ted

Fents it doesnt really matter. Theres no EXACT magnet type for the job. A mate of mine built one out of flat, crescent shaped broken bits of magnet from an old computer, and he gets a wicked vortex.


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## Fents

thankyou guys.


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## Gar

As Ted said, even if you get the cheapo thin mags you can glue a few together to get the job done (like I did)...

As for the stir bar, I use a 40mm egg shaped one, I've only used it up to 2L but it vortexes that no worries, I have heard that the bars the ring in the middle tend to be a bit noisy.


----------



## Wolfy

Fents said:


> can anyone point me to a site that i can buy the exact rare earth magnets and a stir bar i need pls, i cant be assed to trawl through 50 pages. shanks.


Except this thread has only 3 pages ...


Fents said:


> thanks du99, rang SSL. only problem is i have no idea what size magnets or stir bar....guess i'll have a search hey argon?


The pictures and text on the first page should give you good/easy answers, you might have to read a bit but I'm sure it's there.


----------



## Fents

yep argon already gave me the 'your a lazy prick' reply, but thanks wolfy i guess i just didnt read your first post proper, apologies to all and sundry for being shit, i've been here long enough to know better.

i went with these - http://www.dealextreme.com/p/super-strong-...10mm-x-1mm-5962

can anyone tell me if this stirbar will be ok as someone on the last page suggested the ones with the line in the middle are noisy?? http://www.ebay.com.au/itm/Stirbar-Egg-Sha...=item2eb916f462


----------



## benno1973

Hey Fents,

Your stirbar should ideally be around about as long as the magents are far apart (or vica versa), so it can depend a bit on the fan you're using. Measure the fan and estimate where your magnets are going to go, then measure the distance between the centres of the magnet. 

Having said that, 25mm is what I use, but not egg shaped. It's a little noisy - I hear that the ones with the ring in the middle are much louder. I bought mine from seratech when sera was selling them (I think?). I can't see them on his website anymore, but I think he used to sell them.

And those magnets will be fine. You might need to glue some together, but you have 10 of them, hey?!!


----------



## argon

:icon_offtopic: 



Fents said:


> yep argon already gave me the 'your a lazy prick' reply... snip




yeah sorry... had the cranky pants on this morning, wife had the shits with me this morning and i get into work and the coffee machine is broken. :angry:


----------



## felten

Fents said:


> yep argon already gave me the 'your a lazy prick' reply, but thanks wolfy i guess i just didnt read your first post proper, apologies to all and sundry for being shit, i've been here long enough to know better.
> 
> i went with these - http://www.dealextreme.com/p/super-strong-...10mm-x-1mm-5962
> 
> can anyone tell me if this stirbar will be ok as someone on the last page suggested the ones with the line in the middle are noisy?? http://www.ebay.com.au/itm/Stirbar-Egg-Sha...=item2eb916f462


I use an egg shaped bar though it looks to be a different shape, it does the job, and it's silent as well. 

It's the same length as the hub on my CPU fan too, which means it sits well on the magnets at either end.


----------



## benno1973

Kaiser Soze said:


> Quick question, maybe it's already been asked but I can't see it in this thread, and it's been a while since I read the Tight Arse Stir Plate thread, so here goes...
> 
> I see lots of people using LED dimmers in these projects, 12V 0-8A. As most of the fans we're using are around 0.3A, doesn't that mean that the max draw by the fan is 0.3A? So how does a 0-8A dimmer work? I assume that it adjusts the amps between 0 when the dial is at minimum, and 8A when the dial is at max? So wouldn't the fan be at max speed after turning the dial just to the right a little?
> 
> Obviously I haven't used one myself, so I don't know. And I know nothing about electronics, that's probably obvious.






Kaiser Soze said:


> These are the dimmers. They specify output power 96W, output current 8A. I assume that they are for a bunch of LED lights, not just a single light. Still, as you point out, LED lights draw bugger all, so I'm not sure how these work exactly...






DazDog said:


> They are pretty cheap. About half way on the dial is the fastest I get get a stirrer to spin. And lower produces a slightly slower spin so you do have some control with it.



So I bought an LED dimmer as referenced in the above link. I hooked it inline between my power source (12V, 500mA) and the fan (12V, 170mA). The problem is, the fan spins at full speed, no matter what the dial is set to. Even if I turn it all the way around to 'off' the fan is going full tilt. I would expect that all the way to the 'off position' would supply 0A, so there's be no power? Has anyone else got experience with these dimmers, and do they stop the fan in the off position? Maybe my dimmer is dodgy?


----------



## Wolfy

Kaiser Soze said:


> So I bought an LED dimmer as referenced in the above link. I hooked it inline between my power source (12V, 500mA) and the fan (12V, 170mA). The problem is, the fan spins at full speed, no matter what the dial is set to. Even if I turn it all the way around to 'off' the fan is going full tilt. I would expect that all the way to the 'off position' would supply 0A, so there's be no power? Has anyone else got experience with these dimmers, and do they stop the fan in the off position? Maybe my dimmer is dodgy?


Sounds like it's broken, or you're doing something wrong.


----------



## Dazza88

Wire up differently I am guessing. Inline? Have you wired fan into one side and ac onto other?
My guess . . .


Code:





Actually, wiring is pretty obvious prob dodgy dial. Weird it runs all the time.


----------



## booargy

check the supply output is DC. It probably won't work on AC


----------



## Dazza88

The positive wires sit next to each other on the device, are they touching? This would bypass the dial


----------



## benno1973

Thanks guys.

Yes, the power supply is 12V DC, not AC.
It is wired up correctly, otherwise it wouldn't run at all I'm guessing. DC supply into the INPUT (V-/V+) and the fan into the OUTPUT (V-/V+). I checked that the wires aren't touching - you're right they are pretty close together but I made sure they weren't in contact.

Just wondering if there's an easy way to test it to confirm deny whether it's working.


----------



## Brewman_

I like the ideas about stir plates, very simple and cheap, and I am thinking about making one, but always considered a stir plate with an aeration or oxygen injection. But looking at the pics I don't see any of that. I am I missing that bit? Or do you get good results with just the stir plate?

Fear_n_loath


----------



## benno1973

You get great results with just the stir plate. I tend to shake (aerate) the starter, then on the stirplate you're constantly moving the surface of the wort around in contact with air and this introduces further oxygen. That, in conjunction with keeping the yeast in suspension, makes things move fast. I factor in a day for each step up from a slant, but I could easily get away with half a day given how fast things move with a stirplate.


----------



## ledgenko

Ok guys .... I am building as we speak but as luck would have it I happened upon a 240v 12cm ball bearing rotary fan made by none other than D- word smith (as my son calls Dick Smiths - ok its kinda cute and funny at the same time) but made in none other that Taiwan .. Dick would and should be ashamed !!!! see photo .. but what I want to know is it going to be too powerful and because it is 240v can I use a ceiling fan control to adjust the speed ??? and also will I need the same number , more or less magnets ??? 

For your consideration and comment... 

BTW ... I have no idea where this came from and what its original use was but thought hell this could be a more funner build  

Yes I meant it !!


Matt


----------



## Wolfy

ledgenko said:


> .. but what I want to know is it going to be too powerful and because it is 240v can I use a ceiling fan control to adjust the speed ??? and also will I need the same number , more or less magnets ???


It's not likely to be too 'powerful' - when built (with a ceiling fan controller) - it will likely put out the same RPM.
However, you'll be playing with lethal 240V and not mostly-harmless 12V so it's not something I'd recommend.


----------



## spog

just remembered (bit late now),but i think it was the december aussie issue of the silicon chip magazine had a section on building a stir plate.
maybeyour library has it or someone you know.......cheers.......spog.........


----------



## alfadog

ledgenko said:


> Ok guys .... I am building as we speak but as luck would have it I happened upon a 240v 12cm ball bearing rotary fan made by none other than D- word smith (as my son calls Dick Smiths - ok its kinda cute and funny at the same time) but made in none other that Taiwan .. Dick would and should be ashamed !!!! see photo .. but what I want to know is it going to be too powerful and because it is 240v can I use a ceiling fan control to adjust the speed ??? and also will I need the same number , more or less magnets ???



I am not sure how the magnets work with the AC, but give it a go and let me know


----------



## pyrosx

I love this thread. Never had the chance to continue high school chemistry onto Uni levels - so never got to play with a stir plate - always wanted to though. (Edit: forgot to say "Thanks!")

Couple of purchases from dealextreme (followed by the customary agonising couple-week-wait), and i've got a stir plate!

The stir bar was delivered much quicker than the dealextreme gear, so I had it ready - attaching the magnets in the right place on the fan was actually pretty straight forward: I left the stir bar in the small plastic bag it came in (just as a superglue insurance policy), organised both piles of magnets into place on the stir bar. Because I know knew that the magnets were the right space apart, the hard part was done. Superglue was applied directly to the other side of the magnets, then stuck into place as close to centre on the fan hub as I could - an hour later, I tested it out, and it worked perfectly. Liberal applications of cardboard and electrical tape have it looking like a proper ghetto unit. I was thinking i'd go back and glue or otherwise more-permanently attach stuff later on, but right now, my thinking is "why bother?".






My only worry is the speed i've achieved: I used an old 5V nokia charger, and have not had to use the separate speed controller I bought - 5V with the fan I bought seemed to get a pretty decent amount of agitation going - I don't get a massive vortex in 2L flask when it's pretty full, but i do get a pretty decent (2-3cm) indentation, and shit is definitely being stirred around... anyone experienced know if a more forceful agitation is required? This picture shows about 4-500ml of starter and some cooperspaleale yeast (stepped up overnight with 100ml starter), and while there's not a massive vortex, there's a definite indent, most of the liquid is moving even at the edges, and there's definite bubbling - that's all thats really required, right?


----------



## Dazza88

Looks good to me, after two days take it off the stir plate, let it settle and see how much of a yeast you have.


----------



## bruce86

I was looking into all this tonight and sussed out from my elecy mate if i could use a charger (5v) with the fan that needs 12 v he said that it will try drawing the whole 12v out of the transformer and prob cause the fan to burn out quicker (im pretty sure that is what he ment) If u already have the 12V power supply you may as well use it may save your fan in the long run.


----------



## pyrosx

bruce86 said:


> I was looking into all this tonight and sussed out from my elecy mate if i could use a charger (5v) with the fan that needs 12 v he said that it will try drawing the whole 12v out of the transformer and prob cause the fan to burn out quicker (im pretty sure that is what he ment) If u already have the 12V power supply you may as well use it may save your fan in the long run.



Using a bigger power supply and a resistor is going to.... ugh - my elec eng skills have massive cobwebs... higher voltage, so lower current. What this means in practical terms to the fan is beyond me though... probably more current through the coils, so a possibility of more heat and burnout - doesn't feel hot though. I'll keep an eye on it though - I hadn't thought of my ghetto cardboard solution in terms of fuel for a fire :/

Obviously under-powering anything isn't exactly "ideal", and the warranty is probably void - but it cost less than $3 - so i'm comfortable with that.

Once this starter is done i'll probably look at finding a beefier phone charger and include the pot for speed control - probably nicer anyway.


----------



## vortex

I've picked up the parts to build a new dual stir plate, two 120mm fans and two fan speed controllers; hopefully one of these will be powerful enough for a 5L lager starter.

Just wondering though, has anyone cracked open a professional stir plate to see how the magnets are placed/arranged? Just curious, as i've had a few issues with throwing stir bars on my DIY plate and i'm wondering if it's because of the placement of the magnets. I've also had a few thoughts on magnet arrangement, and just wondering how the magnets in a professional stir plate are arranged.


----------



## Wimmig

I just ordered the parts for a stir plate, 12v version. So far, the bits cost $12.50. Going to use a cigar box from work so that's free. All that's left is a stir bar and a flask


----------



## black_labb

I have most of what I need for a stirplate from uni projects. a variable dc power supply (up to 12v), some neodynum magnets and a few small motors that work off 12v. Just need to mount it all together.


----------



## Camo1234

I have just built my first stir plate and having a few issues with getting the stir bar to stop spinning off.


I have a small and large stir bar and have used 2 sets of 8mm x 1mm magnets 3 high so that you have 4 sets across the fan. I can get the small stir bar to spin while I keep the fan going slow but when I speed it up it shots the stir bar off.... the larger stir bar pretty much shoots off straight away...



What do you think my issue is? Are my magnets not strong enough or are they not aligned correctly? with the small one I can get a small vortex but it makes plenty of noise and doesn't really spin quietly... i have the staight stir bars like have been recommended on here, are thesse supposed to go quietly?


Cheers guys, any help appreciated.



Camo


----------



## benno1973

Are you using a flat bottomed flask or something with a flat bottom for the starter? Anything with a slightly domed bottom (V8 jars, glass jars, 2L demijohns etc) are a bitch to get going. Also, if you can get a really slow spin on the stir bar, then you'll be more likely to keep it from spinning off.


----------



## Camo1234

Kaiser Soze said:


> Are you using a flat bottomed flask or something with a flat bottom for the starter? Anything with a slightly domed bottom (V8 jars, glass jars, 2L demijohns etc) are a bitch to get going. Also, if you can get a really slow spin on the stir bar, then you'll be more likely to keep it from spinning off.




Hey mate, i am using a 2 ltr erlenmeyer flask so I assume it has a flat bottom. How vigorous does the whirlpool need to be? is a slow spin ok or does it need to go crazy like the You tube videos? I have the dimmer knob hooked up and can get the small bar slowly spinning well so I might just stick with that for now.


----------



## Wolfy

Camo1234 said:


> I have a small and large stir bar and have used 2 sets of 8mm x 1mm magnets 3 high so that you have 4 sets across the fan. I can get the small stir bar to spin while I keep the fan going slow but when I speed it up it shots the stir bar off.... the larger stir bar pretty much shoots off straight away...
> 
> What do you think my issue is? Are my magnets not strong enough or are they not aligned correctly? with the small one I can get a small vortex but it makes plenty of noise and doesn't really spin quietly... i have the staight stir bars like have been recommended on here, are thesse supposed to go quietly?


The not spinning quietly would also indicate that it's not-so-stable.
If you've put the magnets the 'right' distance apart (as suggested at the start of the thread) then I'd try adjusting the distance between the flask-bottom and the magnets, either raise or lower it and you should get to a 'sweet spot' where both stir-bars are stable at all speeds. How you raise/lower the distance depends on what enclosure you are using.

The straight stir-bars should be mostly quiet - just a small tinkle-sound as it spins around.


Camo1234 said:


> How vigorous does the whirlpool need to be? is a slow spin ok or does it need to go crazy like the You tube videos?


You only need enough of a vortex to mix in oxygen and to stir the yeast - so it does not need to be a super-whirlpool like many videos.


----------



## Camo1234

Wolfy said:


> The not spinning quietly would also indicate that it's not-so-stable.
> If you've put the magnets the 'right' distance apart (as suggested at the start of the thread) then I'd try adjusting the distance between the flask-bottom and the magnets, either raise or lower it and you should get to a 'sweet spot' where both stir-bars are stable at all speeds. How you raise/lower the distance depends on what enclosure you are using.
> 
> The straight stir-bars should be mostly quiet - just a small tinkle-sound as it spins around.
> 
> You only need enough of a vortex to mix in oxygen and to stir the yeast - so it does not need to be a super-whirlpool like many videos.



Cheers... I have it going now, well enough to grow yeast anyway!

It is literally a computer fan with a few cardboard spacers and a tupperwear lid at the moment with the flask on top.... it is spinning nicely with a little noise.

I'm not the most handy person going around but slowly getting these things going... Haven't really been a "build it" person until I started brewing.... I would usually just buy things i needed... But I am starting to actually enjoy the feeling of pride when I put it together.... So far I have done my STC1000 (was nervous I would kill myself so got a sparkie to look over it and he was happy :icon_cheers: ), computer fan blower to cool my keggerator font and now my sort of stir plate!


Time to think about an enclosure!



Camo


----------



## Wolfy

Camo1234 said:


> It is literally a computer fan with a few cardboard spacers and a tupperwear lid at the moment with the flask on top.... it is spinning nicely with a little noise.


Easy then - add/remove spacers until it all spins fine.


----------



## Camo1234

Hi Guys


Sorry, school boy question here.... First go at a starter and also using a stir plate and not really sure if I am seeing a krausen or just bubbles from the airation.









This is the second step, first step was 1 ltr with half a smack pack, the stir bar fell off so the yeast settled after 24 hours so I stepped it up with 1.5 ltrs and now after 48 hours this krausen is still there.


I feel like my first few brews watching it like a hawk!


ps... yes that is my dodgey stir plate! enclosure will come another day.

also, i am heading camping for the weekend so will the starter be OK if I just put it in the fridge from Thurs night to Sun night and then pitch Sun night?



Cheers Fellas... Camo


----------



## Camo1234

Bump???





Camo1234 said:


> Hi Guys
> 
> 
> Sorry, school boy question here.... First go at a starter and also using a stir plate and not really sure if I am seeing a krausen or just bubbles from the airation.
> 
> View attachment 53065
> 
> 
> View attachment 53066
> 
> 
> 
> This is the second step, first step was 1 ltr with half a smack pack, the stir bar fell off so the yeast settled after 24 hours so I stepped it up with 1.5 ltrs and now after 48 hours this krausen is still there.
> 
> 
> I feel like my first few brews watching it like a hawk!
> 
> 
> ps... yes that is my dodgey stir plate! enclosure will come another day.
> 
> also, i am heading camping for the weekend so will the starter be OK if I just put it in the fridge from Thurs night to Sun night and then pitch Sun night?
> 
> 
> 
> Cheers Fellas... Camo


----------



## Wolfy

Camo1234 said:


> Sorry, school boy question here.... First go at a starter and also using a stir plate and not really sure if I am seeing a krausen or just bubbles from the airation.
> ...
> also, i am heading camping for the weekend so will the starter be OK if I just put it in the fridge from Thurs night to Sun night and then pitch Sun night?


Why does it matter? What are you actually trying to ask? You're looking to grow yeast not ferment starter-beer.
If your yeast starts fermenting (when you see krausen/activity), it's already grown as much as it's going to - usually that takes 12-24h (48h maximum) after that time having the stir-plate turned on is not essential.

If you are asking has it done it's thing, grown, fermented, behaved as expected:

Turn off the stir-plate, and view the yeast-sediment that settles to the bottom - you should have a nice layer of yeast (much more than you started with).
Check the gravity, if the gravity has dropped (it likely grew, fermented and finished all while you were watching) then things are done.
The brown-yeast-skum-layer on the side of the flask that is higher than the froth, indicates to me that it's done and dusted, fermented and finished - but that's a guess that does not need to be made if you do the two things above.

Putting the yeast in the fridge for a few days should not hurt things too much.


----------



## Camo1234

Hey Wolfy, cheers for the reply. You have explained it perfectly! I was waiting for the krausen to settle out as I thought i had read somewhere that I should let the starter ferment out :blink:


----------



## Wolfy

Camo1234 said:


> I was waiting for the krausen to settle out as I thought i had read somewhere that I should let the starter ferment out :blink:


If you are stepping a starter (as you did) there is no need to wait for it to ferment, simply step it up after about 12-48h (depending on size, yeast etc).

On the last step of the starter (especially if the yeast will be stored for a few days) it can be beneficial to let it ferment-out and then give the time for the yeast to settle - however this process (again depending on size, yeast etc) is still usually very fast 24-48h.


----------



## crd0902

Hey all I'm just gettin started building my stir plate. I have a fan and a 5 and 9 volt power supply. Trying to find adimmer. What size magnets are good. I have a choice 10 by 1 mm, 8 by 1 mm and some three mm and five mm thick. Not sure what to go for. Also I cant find a stir bar without the pivot ring. Any advice cheers


----------



## Gar

Dimmer - the guts can be taken out of the box if you'd like to make it more compact.
http://www.ebay.com.au/itm/New-12V-8A-Led-...=item256cd4bb47

5mm thick magnets sound nice... old HDD magnets are good too.

Got my stir bar without pivot ring from http://www.livingstone.com.au they're a bit finicky with who they deal with though, not sure why they trust me :lol:


----------



## crd0902

Thanks I found some stir bars on ssapl.com so I'll try your site if I have no luck. I think I'll go for the 5 mm magnets as I just read somewhere else they are good ones. Thanks for the advice. I'll be back once it's built


----------



## bullsneck

I'm having trouble keeping the stir bar on. I have exactly the same system as you Wolfy. I bought what you did so it would work.

However, the stir bar keeps flying off, even at the lowest speed. My thoughts are because it is a bit longer than yours, measuring 5cms or so. Will a smaller stir bar work?


----------



## Wolfy

bullsneck said:


> I'm having trouble keeping the stir bar on. I have exactly the same system as you Wolfy. I bought what you did so it would work.
> 
> However, the stir bar keeps flying off, even at the lowest speed. My thoughts are because it is a bit longer than yours, measuring 5cms or so. Will a smaller stir bar work?


Could be because the stir-bar is longer, especially if your magnets are close together, or could be that the height between the bottom of the flask and the magnets is a problem, so try adjusting that first.


----------



## vortex

vortex said:


> I've picked up the parts to build a new dual stir plate, two 120mm fans and two fan speed controllers; hopefully one of these will be powerful enough for a 5L lager starter.



Got both of these up and running now, they spin 5L of water OK in an Erlenmeyer, but 5L of wort at a higher density I'm not so sure about yet.




Untitled by auvortex, on Flickr
(Spot the dummies and baby stuff... one of the reasons I brew!)




Untitled by auvortex, on Flickr




Untitled by auvortex, on Flickr




Untitled by auvortex, on Flickr

Rather than looking for smaller round neo magnets like I had in my old stir plate, I picked up 10x rectangular Neo magnets from a retailer on eBay (I can find specific details if anyone likes, cbf logging into eBay right now) for a decent price, was like $25 for 10 or something reasonable like that. A couple of CoolerMaster 120mm LED fans ($25/both), some PC fan speed controllers ($2 each!) and some tupperware containers nicked from the SWMBO's cupboard and they're basically done. I need to pick up some power sockets from Jaycar and i'm ready for a winter of Lagers!

I can't take credit for the tupperware, I saw the idea here somewhere with the specific goal of catching yeast spillage; have had a couple of overflows with my old stirplate, so this will catch it.

These fans, being 'enthusiast' PC fans are not very high RPM (to keep them quiet) so I can run them at 12v flat out and they don't spin too fast, 1200RPM is their max RPM to be exact. I am planning to pick up some faster fans so the stirplates can both spin faster, but honestly these are still pretty good fans to use and they do generate a small vortex.

The rectangular magnets have ment my small and long stirbars all work perfectly unlike on my old stirplate which only used smaller magnets, only my short stirbars would work in these..


----------



## iralosavic

I've got a similar container! Good idea on the rectangular magnets, mate. Haven't tested my 28mm bar out in 5L wort yet either, but it stirs the crap outta a litre.


----------



## Wolfy

Picked up a 5L flask today (at the price from KegKing its hard to go past), it's only blue food-colouring at the moment, but I'm sure that the stir-plate design outlined at the start of the thread will have no problem with 5L of wort/yeast.






What I did find interesting is that in the shop they do not have the fan mounted on anything at all.
The fan sits on the bench, and the flask sits on 4x silicon bung that rest on the bench around the fan - so simple and so easy.


----------



## peaky

Nice one wolfy. How much was the flask? Keen for one of those as I want to ferment double batch lagers.


----------



## Dazza88

I like those rectangular magnets, do they allow you to use a range of stir bar sizes? My spaced out circular ones will only spin the 1 inch stir bar i bought originally.


----------



## Wolfy

peakydh said:


> Nice one wolfy. How much was the flask? Keen for one of those as I want to ferment double batch lagers.


List price is $39, but I got mine for $35 - either way very cheap for that size.


----------



## peaky

Wolfy said:


> List price is $39, but I got mine for $35 - either way very cheap for that size.



Jeez! That's a bargain, gettin' me one for sure. I thought they'd be double that.


----------



## vortex

DazDog said:


> I like those rectangular magnets, do they allow you to use a range of stir bar sizes? My spaced out circular ones will only spin the 1 inch stir bar i bought originally.



They sure do. Up to the length of the magnets will work fine, I have 38mm, 42mm and 52mm stir bars, all are fine. The 52mm is about the limit because of the size of the magnets (they're 50mm total, 25mm each); but you could spread them out and make longer stirbars work OK, at the expense of shorter ones if that's what you wanted to do.

My older stirplate with the round magnets works with the 38mm and 42mm, but the 52mm throws straight away.


----------



## Dazza88

Cool. My stir plate will only spin the 1 inch. i scored a bargain of yeast prep stuff including at least 5 stir bars of various sizes, haven't been able to used them due to lack of being assed to build a new fan with magnets set up. Maybe i will get some of those ones rect. ones.

BTW those cheapo LED dimmers suggested in this thread (or the other one?) has latest fine for me for about 9 months, used it for 48+ hours on starters. e.g http://www.ebay.com.au/itm/LED-Light-Dimme...=item27bfe245da


----------



## peaky

Yeah, those rectangle magnets look the business. I may need to upgrade my stir plate once I get a 5L flask. The current version spins up 2L ok but not sure about a starter more than twice that size. I'm limited to a 1 inch stir bar atm.


----------



## iralosavic

Peaky: you may be surprised. Many people report great success with small bars in large volume worts. I'm crossing my fingers with mine. I'll let you know - I already have a 5L flask, just haven't tested the stirrer on it yet.


----------



## peaky

iralosavic said:


> Peaky: you may be surprised. Many people report great success with small bars in large volume worts. I'm crossing my fingers with mine. I'll let you know - I already have a 5L flask, just haven't tested the stirrer on it yet.



Hoping my stir plate will spin 5L, but if it doesn't then I have another brewery project. I don't really need another project right now, it has taken me 5 weeks so far just to fit a sight glass to my HLT! I think I've spent on average about 4 minutes a week working on it....


----------



## iralosavic

Haha totally on the same page, mate. I have so many unfinished projects and it's not from a lack of motivation, I'm simply needed around the clock at either work or home (two high needs babies). I finally managed to calibrate my sight glass a few weeks ago after months of walking past it and daydreaming lol I'm still waiting to find the time to finish my false bottom. Stir plate has been 2 months in the making (mostly waiting for slow shipping).


----------



## Wolfman

I looked at one of those 5L flasks, thought to myself WOW that's freaking HUGE!


----------



## iralosavic

Haha they are bloody ginormous in flesh and blood. I'm always paranoid I'll break it everytime I move it around. So much surface area to accidentally knock against something.


----------



## peaky

I thought the 2L was big when I got it, looking forward to being able to make some big lager starters with a 5L.


----------



## Wolfy

iralosavic said:


> Haha they are bloody ginormous in flesh and blood. I'm always paranoid I'll break it everytime I move it around. So much surface area to accidentally knock against something.


LOL yep. Getting it out, washing it, and setting it up just to take a few photos - after having a few beers - was not a good idea .... so I decided _after _doing it yesterday.


----------



## Wolfman

I'm spewing I didn't buy one now! 

Got home and SWMBO says you should have bought more as they would make a great flower vase!


----------



## peaky

Wolfman said:


> I'm spewing I didn't buy one now!
> 
> Got home and SWMBO says you should have bought more as they would make a great flower vase!



Haha! Spares in case you break one...


----------



## Wolfy

KegKing display their 5L flasks with a DIY stir-plate on their counter.
The mounting setup was so simple and easy I asked them to take a couple of photos for me to share here.




As you can see, the fan simply sits on the bench with 4 rubber stoppers for the flask to sit on, it also seems they've used some type of blue-tack or putty to stick the magnets to the fan.
But no matter how simple it is, it works well:


----------



## brad81

I saw this setup on Tuesday. Love how they did the switch. Very ghetto, but who cares!

So I ripped an old PC apart, removed the fans (including the PSU fan). And now have a few spare to tinker with.

Wait for hard garbage, have a phillips head in the car, and go for a drive.


----------



## mikec

I just noticed this stir "bar" on the proscitech website.
Do you reckon it would be better, worse, or no difference?


----------



## brad81

Well, went ahead and made it. Left off the switch. Cost me about $30-40 all up.

I'm colour blind so I had to enlist SWMBO to tell me that the orange wire was actually red on the PS.


----------



## Fourstar

vortex said:


> Got both of these up and running now, they spin 5L of water OK in an Erlenmeyer, but 5L of wort at a higher density I'm not so sure about yet.
> 
> Rather than looking for smaller round neo magnets like I had in my old stir plate, I picked up 10x rectangular Neo magnets from a retailer on eBay (I can find specific details if anyone likes, cbf logging into eBay right now) for a decent price, was like $25 for 10 or something reasonable like that. A couple of CoolerMaster 120mm LED fans ($25/both), some PC fan speed controllers ($2 each!) and some tupperware containers nicked from the SWMBO's cupboard and they're basically done. I need to pick up some power sockets from Jaycar and i'm ready for a winter of Lagers!
> 
> I can't take credit for the tupperware, I saw the idea here somewhere with the specific goal of catching yeast spillage; have had a couple of overflows with my old stirplate, so this will catch it.
> 
> These fans, being 'enthusiast' PC fans are not very high RPM (to keep them quiet) so I can run them at 12v flat out and they don't spin too fast, 1200RPM is their max RPM to be exact. I am planning to pick up some faster fans so the stirplates can both spin faster, but honestly these are still pretty good fans to use and they do generate a small vortex.
> 
> The rectangular magnets have ment my small and long stirbars all work perfectly unlike on my old stirplate which only used smaller magnets, only my short stirbars would work in these..




I've been eye balling those speed controllers for a few weeks now and decided its time to trick up my stir-plate to MKII so I can properly handle 2L starters. My current stir plate set-up in a jaycar jiffy box throws the bar at low speeds and can be a pain when you set it up overnight to wake up and find it no longer spinning. My plan was almost identical to yours but with a few extra tricks. 100% plug and play. Hopefully the fan controller will run off 5V. otherwise ive wasted $2.50 (what a shame.)

USB AC wall charger - http://www.ebay.com.au/itm/200676592190 $1.00
3 pin molex to usb adapter. - http://www.ebay.com.au/itm/360440336469 $1.50
Fan controller - http://www.ebay.com.au/itm/251073464439 $2.71
70mm Case Fan 3 pin - http://www.ebay.com.au/itm/300641239992 $2.59 

Slap on a tupperware container from 2 dollar shop and the whole thing is ready to fire in less than $10.

Or as wolfy has done i could mount it on a fermenter lid and trim the cost down further.


----------



## pimpsqueak

Cheers Wolfy. Another piece of ghetto equipment to add to my collection...


----------



## Wolfy

Fourstar said:


> USB AC wall charger - http://www.ebay.com.au/itm/200676592190 $1.00
> 3 pin molex to usb adapter. - http://www.ebay.com.au/itm/360440336469 $1.50
> Fan controller - http://www.ebay.com.au/itm/251073464439 $2.71
> 70mm Case Fan 3 pin - http://www.ebay.com.au/itm/300641239992 $2.59
> 
> Slap on a tupperware container from 2 dollar shop and the whole thing is ready to fire in less than $10.


Great links to everything you need, pity I can't edit the first post.



pimpsqueak said:


> Cheers Wolfy. Another piece of ghetto equipment to add to my collection...


Someone else with excess fermentor lids ... cool.


----------



## bullsneck

Here's some photos of mine in action.

It's on the Bayside Brewers Blogspot


----------



## Fourstar

Wolfy said:


> Great links to everything you need, pity I can't edit the first post.



Except the speed controller is redundant after i noticed on the packaging it controls 12V down to 5V(if only the listing told us that.) given the USB connector is 5V directly driving all components. Cannot be used even as a switch.


----------



## 1974Alby

what output are peoples power supplies? Im using a 300mA phone charger and I cant get it spinning fast enough to create a vortex even in 500ml :angry:


----------



## Dazza88

how big is ur stirbar?


----------



## bullsneck

I'm using a 12v 400mA power supply to push my stirplate. The bar is 25mm or 30mm long, I forget and it's spinning at the moment so I can't measure it. This link shows that the vortex is almost too big.

Edit - spelling


----------



## Dazza88

That was directed at Albanian but I should prob ask how many volts, 25mm should liter starters.


----------



## 1974Alby

not sure of the size...I would estimate 25-28mm ish...its 12v

edit...just double checked..Its only 9v, 300mA


----------



## Wolfy

Albainian said:


> not sure of the size...I would estimate 25-28mm ish...its 12v
> 
> edit...just double checked..Its only 9v, 300mA


Assuming its a 12V fan, the fact the transformer is 9V is most likely the issue for it not spinning fast enough - even the large 120mm LED 12V fans (as per the first post in this thread) are rated at 0.30A.


----------



## Dazza88

This power supply should do the trick, 3 bucks.

http://www.ebay.com.au/itm/AC-100-240V-DC-...3#ht_2674wt_957


----------



## 1974Alby

yep..its a 12v 120mm led fan...needs more juice...

I have another one here that says

Pri.: 240V ~50Hz 135mA
Sec.: 12V - 1A 12VA

Im guessing that this is 12v 1000mA output...its from a modem router. Does this sound better?


----------



## 1974Alby

swapped power supply and now it goes like the clappers...still cant get a vortex though, I think 550ml in a 500ml erlenmeyer is just too full for get the vortex...next step up is to add the 550ml into 1.4L in a 2L flask...this will give me 1.95L ...again I think it unlikley to get a vortex at these volumes.


----------



## vortex

Albainian said:


> swapped power supply and now it goes like the clappers...still cant get a vortex though, I think 550ml in a 500ml erlenmeyer is just too full for get the vortex...next step up is to add the 550ml into 1.4L in a 2L flask...this will give me 1.95L ...again I think it unlikley to get a vortex at these volumes.


No, you should easily get a vortex with those volumes. My 120mm can vortex 5L of plain water in a 5L flask. Your stirbar may be too short, however.

At the end of the day though, you don't really need a massive vortex - all you're actually looking to do is to move the liquid around enough to exchange the surface (and keep yeast in suspension of course) to keep oxygen absorption happening, so the yeast have all the oxygen they need. If it's moving the wort around, gas exchange is happening. A vortex simply means the liquid is spinning faster and has more surface area so you MAY get slightly better gas exchange (oxygen absorbed, CO2 knocked out of solution) but not entirely critical to a successful starter (look how many people make starters successfully just by shaking the bottle/flask).


----------



## 1974Alby

its a 20mm+ stir bar (might even be 25mm)...I know I dont need a vortex, but I WANT ONE!!! That would make me feel like my stir plate was as cool as everyone else's!


----------



## tipsy

Thanks for this thread. 
Used mine and can't believe how quick it got a 5lt starter fermenting.

FWIW I've used the lid idea but just keep the fan sitting underneath (not attached)

To get the right hight I just kept stacking the cheap Chinese magnets up until it spins nicely.
I think I've got about 10 on there.


----------



## Dazza88

Albainian said:


> its a 20mm+ stir bar (might even be 25mm)...I know I dont need a vortex, but I WANT ONE!!! That would make me feel like my stir plate was as cool as everyone else's!



So the bar is spinning with the fan at higher speeds? I get a vortex with 1 inch bar in volume less than a litre and sufficient movement for 1.25 l starters.


----------



## 1974Alby

yep its spinning and I can see the wort moving gently, but no vortex. I thought the problem was not the volume, but the depth as the flask is nearly full.


----------



## alfadog

DazDog said:


> This power supply should do the trick, 3 bucks.
> 
> http://www.ebay.com.au/itm/AC-100-240V-DC-...3#ht_2674wt_957



I had three of these power supplies for my fridge fans, two of them failed within a fortnight. I am saving the last for my stir plate. Was not too happy with them


----------



## alfadog

I finally got the parts today to build my stir plate and it was a bit tricky getting the magnets on the fan. So I had to do a Macgyver job.





I placed all the magnets on a strip of blu-Tak which allowed me to get the distances perfect. I then dabbed on some silicone and placed the whole strip on to the fan assembly. Works a treat! Now to make me some starters.


----------



## Acasta

Built one of these but I guess i've done it wrong. It will only go at full speed and not move at lower settings

I used a normal 120mm fan, and a 12V power supply and of these fan speed adjusters:
http://www.ebay.com.au/itm/221037047346?ss...#ht_4449wt_1002

When ordering the power supply off ebay, the accidentally sent me one of these, but I'm not sure I can use it as its 12-24V>
http://www.ebay.com.au/itm/Wireless-Remote...9#ht_4885wt_905

I'm thinking I'll get one of those dimmers. Thoughts?


----------



## glenwal

Acasta said:


> When ordering the power supply off ebay, the accidentally sent me one of these, but I'm not sure I can use it as its 12-24V>
> http://www.ebay.com.au/itm/Wireless-Remote...9#ht_4885wt_905



That should be fine to use. 12-24V just means you can use it on any power supply thats between 12V and 24V, so if you have a 12V supply for your fan, its perfect.

Remote controlled stir-plate sounds pretty cool.


----------



## Acasta

Cheers! Yeah, handy so I can control the speed from across the room!
Now i need a remote controlled beer tap and fetcher...


----------



## Tony_N

I have just assembled my little jobby in a lunch box, relying on this thread. Thanks Wolfy and others. Just waiting on my ebay magnet which is a rare earth bar magnet 50mmx15mmx10mm for use with a 35mm stirbar (or I will get a 50mm one if needed).

I'm wondering if I have overkilled on the size of the magnet, thinking it might be too heavy for the fan. I ask only because I don't want to superglue the magnet on to find that the fan wont spin it. Anybody know if this is too big? Or alternatively,know of some way of attaching it temporarily without it spinning off and ripping the fan apart?? Or is there any way of releasing superglue without dissolving the plastic on the fan.

Thanks - Tony


----------



## glenwal

Tony_N said:


> Or alternatively,know of some way of attaching it temporarily without it spinning off and ripping the fan apart??



Would bluetac do the trick?


----------



## Tony_N

Glen W said:


> Would bluetac do the trick?



It might if I let it set for a while - praps I'll try it if there is no other solution - thanks Glen


----------



## Tony_N

Tony_N said:


> It might if I let it set for a while - praps I'll try it if there is no other solution - thanks Glen



The magnet is too heavy for the fan to move...$#!%%^& - be good to extract the bar out of the flask though - it is soooo strong


----------



## Arghonaut

Got my stirplate running, thanks to the advice in this thread. Grabbed an old pc, took its 80mm case fan, which came in a convenient mounting case that is a good size for sitting a flask on. Salvaged the magnet from the HDD, and grabbed an adjustable voltage adapter i had lying around. Just bluetacked the magnet to the fan for now. Got a 2L erlenmeyer flask and a 25 and 35mm stir bar. The 25mm works a treat, only throws on the highest voltage, but the vortex is allready all the way down to the stir-bar at that point. The 35mm is no good, too long for the HDD magnet, throws on even the lowest setting.

Now eagerly awaiting some 1388 and 1084 :super:


----------



## geneabovill

Has anyone had any success using other hits of ferrous metal? I tried testing with a pop rivet - it jumps around but doesn't spin. The stir bar is on its way from the states.


----------



## ian ulrick

Is this motor controller suited to run a computor fan for the stir plate and also able to contol the mill motor that Motion Dynamics sells for a grain mill.

Speed controller http://www.ebay.com.au/itm/270859508293?ss...984.m1497.l2649 

Motor http://www.motiondynamics.com.au/worm-driv...s/12v-180w.html 

Baldrick


----------



## warra48

Baldrick said:


> Is this motor controller suited to run a computor fan for the stir plate and also able to contol the mill motor that Motion Dynamics sells for a grain mill.
> 
> Speed controller http://www.ebay.com.au/itm/270859508293?ss...984.m1497.l2649
> 
> Motor http://www.motiondynamics.com.au/worm-driv...s/12v-180w.html
> 
> Baldrick



Geez, I'm interested whether it would work.

The motiondynamics motor is basically designed to propel a golf buggy. I have a golf buggy with just that motor, but with a stuffed circuit board, and I'll be stuffed forking out $200 quoted to replace the controls.


----------



## vortex

Baldrick said:


> Is this motor controller suited to run a computor fan for the stir plate and also able to contol the mill motor that Motion Dynamics sells for a grain mill.
> 
> Speed controller http://www.ebay.com.au/itm/270859508293?ss...984.m1497.l2649
> 
> Motor http://www.motiondynamics.com.au/worm-driv...s/12v-180w.html
> 
> Baldrick


Serious? What size starters are you doing?
a 120mm PC fan with rectangle magnets spins 5L no worries @12v, total of about $10. No need to overkill that much!


----------



## ian ulrick

vortex said:


> Serious? What size starters are you doing?
> a 120mm PC fan with rectangle magnets spins 5L no worries @12v, total of about $10. No need to overkill that much!




I am using a 120mm fan. Not the mill motor :blink: . I am asking about the controller. Is the controller in the link what I am looking for for both applications. I want to control the speed on the stir plate so I can use it for other then just brewing.


Baldrick


----------



## vortex

Baldrick said:


> I am using a 120mm fan. Not the mill motor :blink: . I am asking about the controller. Is the controller in the link what I am looking for for both applications. I want to control the speed on the stir plate so I can use it for other then just brewing.



Apologies, I mis-read (or more likely simply did not!). It will work, but it's massive overkill for a stir plate. I can't comment on what the mill motor would draw when crushing grain though, so I'm not sure if that speed controller will work when the amp draw increases - but it says it supports 10amp though.

All you need for the stir plate is this: http://www.ebay.com.au/itm/QT156-NEW-3-Pin...3c8b&_uhb=1
I have one of these on each of my stir plates.


----------



## ian ulrick

All you need for the stir plate is this: http://www.ebay.com.au/itm/QT156-NEW-3-Pin...3c8b&_uhb=1
I have one of these on each of my stir plates.
[/quote]

Thanks Vortex. I did not find that controller when searching on ebay. Looks the goods.

Baldrick


----------



## Amber Fluid

This Dimmer Switch will do the job too.

Just a note regarding the MD motor, you really don't need a speed controller for it. It does a great job without one.


----------



## geneabovill

Done:


----------



## lael

vortex said:


> Rather than looking for smaller round neo magnets like I had in my old stir plate, I picked up 10x rectangular Neo magnets from a retailer on eBay (I can find specific details if anyone likes, cbf logging into eBay right now) for a decent price, was like $25 for 10 or something reasonable like that. A couple of CoolerMaster 120mm LED fans ($25/both), some PC fan speed controllers ($2 each!) and some tupperware containers nicked from the SWMBO's cupboard and they're basically done. I need to pick up some power sockets from Jaycar and i'm ready for a winter of Lagers!



this looks great - what size magnets did you get? Did you just glue the tips of the magnet to the round hub and the rest is just hanging over?


----------



## vortex

lael said:


> this looks great - what size magnets did you get? Did you just glue the tips of the magnet to the round hub and the rest is just hanging over?



Yeah they're just glued with Tarzans Grip, about 3/4 of the magnets are on the hub so plenty of room to hold them on.
The magnets are 25mm x 10mm x 3mm each.
Exactly these ones: http://www.ebay.com.au/itm/Buy-10-Neodymiu...d2ae&_uhb=1 Aussie seller.


----------



## lael

vortex said:


> Yeah they're just glued with Tarzans Grip, about 3/4 of the magnets are on the hub so plenty of room to hold them on.
> The magnets are 25mm x 10mm x 3mm each.
> Exactly these ones: http://www.ebay.com.au/itm/Buy-10-Neodymiu...d2ae&_uhb=1 Aussie seller.



excellent! thanks! ordered some 30mm x 10 x 4 so should do the job!


----------



## potof4x

Something to contribute and a query as well. Have found and trialled this power supply this and pwm speed control on my 80mm fan stirplate. They seem to work treat and plug together out of the box.

Have the fan to make a 120mm stirplate but can't really find a good budget pro looking box. These at jaycarare ideal but pricey for a plastic box , and these from the UK, but postage is a killer.

Any suggestions for some thing available similar for the right price?


----------



## bullsneck

I got mine (similar to geneabovil's above) from DSE online for half of what they are priced at Jaycar.


----------



## lael

bullsneck said:


> I got mine (similar to geneabovil's above) from DSE online for half of what they are priced at Jaycar.


I tried looking - want a box for a braumiser controller - but had trouble finding anything - would you mind linking?


----------



## lael

I used one of these: to reduce the speed, but have found that the fans make an annoying whining noise. Does anyone know why / have any suggestions?

http://www.ebay.com.au/itm/LED-Light-Dimmer-Brightness-Adjustable-Control-Controller-DC-12V-8A-Bright-Lamp-/140936962822?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D7153136481644901969%26pid%3D100011%26prg%3D1005%26rk%3D2%26sd%3D390502379656%26


----------



## krausenhaus

lael said:


> I used one of these: to reduce the speed, but have found that the fans make an annoying whining noise. Does anyone know why / have any suggestions?


Mine does too - I thought it was going to be a big problem after I built it and made plans to try and insulate it, but I used it for the first time the other day and found that I barely noticed it over any other background noise in the house unless I was standing close to it.

Just whack it in a different room and let it blend in with all the other household sounds.


----------



## lael

insulate it? electrical source? or just to insulate / reduce the noise?


----------



## Acasta

My stir bar just got 'lost'. Any suggestions of getting a cheap replacement? Was thinking a local store might save on shipping. After the 25mm or so ones.


----------



## Helles

Acasta said:


> My stir bar just got 'lost'. Any suggestions of getting a cheap replacement? Was thinking a local store might save on shipping. After the 25mm or so ones.


Grain and Grape have them $10 i think


----------



## felten

After I lost my first one, I bought 4 of them from proscitech.com, $14 for a pack of 4x 50mm oval.


----------



## lael

Just upgraded my stirplate - I found the smaller fans were having trouble starting up with the larger magnets on them.

Went for:
Server Fan - these are POWERFUL, so be careful with your fingers / remove blades if you have kids:
3 fo $40.- http://www.aliexpress.com/snapshot/234389147.html

Controller - http://www.ebay.com.au/itm/12V-8A-PIR-Sensor-LED-Strip-Light-Switch-Dimmer-Brightness-Adjustable-Controller/400514371595

Power Supply (fans are 1.6Amp): http://www.ebay.com.au/itm/120967914339?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Magnets - http://www.ebay.com.au/itm/Big-Super-Strong-Block-Strip-Cuboid-Magnets-Rare-Earth-Neodymium-30-x-10-x-5-mm-/170885527943
but I got a pack of 5 for about $10 from memory?

Drill holes out of the corner mount (8mm) and put through 5/16" bolts in as a stand, with rubber caps from Clarke Rubber over the top. Works so much better with water - haven't tried wort yet.... I've got KegKing erlenmeyer and the bottoms aren't flat - so the oval stirbars produce way less noise.


----------



## KingKong

Finished my build. Very happy with it! Is there a need to vortex when using it with a starter.




ed. I dont know how to turn that around.


----------



## lael

pics


----------



## Edak

Looking good lael  

If anybody else is having trouble with a fan not starting up or working at low speeds then consider making a pwm stir plate, reason is that pwm will still drive at full voltage but pulses instead, which ensures motor doesn't struggle


----------



## lael

Edak said:


> Looking good lael
> 
> If anybody else is having trouble with a fan not starting up or working at low speeds then consider making a pwm stir plate, reason is that pwm will still drive at full voltage but pulses instead, which ensures motor doesn't struggle


cheers Edak! I looked into PWM - have you built a circuit for it? I actually got those fans because they are 4 pin and can take full PWM output. Ideally I would like to use
http://www.overclockers.com/pwm-fan-controller
this circuit to send a 'true' PWM signal to the fans, which would also eliminate the noise. But... my knowledge of electronics is scarce. Any pointers?


Edit - PS to the above post. stirbars in the picture are 70mm oval stirbars - also off aliepxress for $8ea - guy was nice and thew in a 50mm one for free too!  . They are large enough that they recenter themselves if they get thrown and you turn the fan off.


----------



## Edak

lael said:


> cheers Edak! I looked into PWM - have you built a circuit for it? I actually got those fans because they are 4 pin and can take full PWM output. Ideally I would like to use
> http://www.overclockers.com/pwm-fan-controller
> this circuit to send a 'true' PWM signal to the fans, which would also eliminate the noise. But... my knowledge of electronics is scarce. Any pointers?
> 
> 
> Edit - PS to the above post. stirbars in the picture are 70mm oval stirbars - also off aliepxress for $8ea - guy was nice and thew in a 50mm one for free too!  . They are large enough that they recenter themselves if they get thrown and you turn the fan off.


Mine was similar to the one you linked, I used a 555 timer but I don't think I used the diodes on the output. I can take a couple of photos for you if you would like...


----------



## syl

Well I found the answer to my low power issue, only used one HDD magnet thus far. TIME TO HARVEST MORE HDD'S!


----------



## sticksy

quick question from a noob, how important is speed control? cant you just run it flat out? 

thinking ill use a hard drive case as it has a power supply already and slide the fan n magnets in.


----------



## elcarter

Just upgraded mine with new fan and a CPU controller that's got a digital fan RPM lcd.

I cant go past quarter without the sir bar breaking out of the already maxed out 6 magnet field.

When I was initially testing at half power my un-glued magnets flew off, whizzed past my head and hid behind the brew stand for an hour.

If you double up button magnets glue them to as well 

A little bit of rpm control is good - in fact i think needed when you have smaller or larger starters to maintain a good whirl pool and keep the magnet in the magnetic field.

More or less liquid has a decent drag effect and having no control would be hit and miss I think.

Oh yeah super fast fan not so great idea,


----------



## yum beer

Do you need to have a vortex all the time or just the starter stirring.

I get it going hard for a few minutes then turn it down enough to just keep the wort moving. Then crank it up every so often to bring in some extra oxygen.
Surely yeast are not happy living in a whirlpool.


----------



## elcarter

I'm by no means an expert, I think as long as your knocking the Co2 out of solution so you avoid the yeast volcano you should be where you want to be.

If there's any extra benefit / determent from going faster to yeast production / happiness I'm not sure.


----------



## Edak

elcarter said:


> I'm by no means an expert, I think as long as your knocking the Co2 out of solution so you avoid the yeast volcano you should be where you want to be.
> 
> If there's any extra benefit / determent from going faster to yeast production / happiness I'm not sure.


Tell that to 3068! I had mine on a stir plate, about 1.4 L in a 3L flash and it made a huge mess. I hadn't ever seen yeast climb out when being stirred before but hey where there's a will there a way.

I also believe that speed control is a good thing.


----------



## MartinOC

Interesting discussion & linky here: http://aussiehomebrewer.com/topic/76219-stir-plate-speed/?hl=%2Bstir+%2Bplate+%2Bspeed


----------



## elcarter

Cheers for the link Martin, appears going faster makes quite a large difference.

Now I'm wondering how far out my "Brewers Friend" starter calculations are.


----------



## LiquidGold

Finally got around to making my own stirplate thanks to this thread so just thought I'd show how it turned out and ask some questions while I'm at it. First off bit of a noob question, when making a starter for the plate do you just boil the stirer bar at the same time as you boil the wort?



lael said:


> I used one of these: to reduce the speed, but have found that the fans make an annoying whining noise. Does anyone know why / have any suggestions?
> 
> http://www.ebay.com.au/itm/LED-Light-Dimmer-Brightness-Adjustable-Control-Controller-DC-12V-8A-Bright-Lamp-/140936962822?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D11%26meid%3D7153136481644901969%26pid%3D100011%26prg%3D1005%26rk%3D2%26sd%3D390502379656%26


I used the same dimmer and am also experiencing a whining noise, did using a fan without LEDs fix that issue? The noise stops when it's turned on full with mine but that kinda defeats the purpose of having wired a dimmer :blink:

Pics


----------



## MartinOC

Nice one, Centurion!

If you're making your starter wort from DME in the receiving flask, you may as well chuck the stir-bar in at the same time to make sure it's all sanitised.

Don't worry about being able to run the thing at full-tilt. Home-made jobs aren't perfectly aligned & to run it too fast will just throw the bar, defeating the purpose.

As long as you're getting a good circulation & the stir-bar is centred over the magnets, don't worry about speed. Play around with centring the stir-bar in the middle of the flask as it's running, so it's aligned with the magnets (ie. it goes quiet). Job done. It'll work fine.


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## LiquidGold

Yeah I'd like to run it lower than full but the noise I'm getting is not from the stirbar. It's definately the fan since the first time I noticed it was just after wiring up the fan and checking how the dimmer worked. Right away as soon as I give it enough power to light the LEDs but not enough to spin the fan there is a ringing/whiny noise emitted. This noise continues as I wind up the dimmer and only stops once on full.

Looking forward to culturing some more coopers yeast and seeing the difference the stirplate will have on the end result.

Cheers


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## MartinOC

I used a fan that came with it's own potentiometer & never had that problem.

'Just thinking outside the square here:

1. Does your plastic container have any holes in it to allow for/reduce air pressure build-up inside it when the fan is running? It could be that the fan isn't able to lift itself off it's bearings unless it's running at full-tilt & that's the noise problem...?

2. Which way does your fan rotate? Is it pushing air up or down?

Edit: Culturing-up Coopers yeast from a bottle? Give it 3 days & you'll see bugger-all. Don't despair. Day-4 it'll take-off like a train. Patience.....


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## LiquidGold

Fan spins counter-clockwise and is pushing air down but even with the lid off and before the fan was attached to anything it was already making the noise, even before it begins to spin so it makes me think it had to do with the LED or electrical part of the fan somehow. I might try wiring up another computer fan that has no LED to the dimmer and see what happens.


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## LiquidGold

So I wired up another fan to the same dimmer and when turned slightly on there was the same noise but much much quieter and when the fan began to spin it was basically overidden by the noise of the fan spinning. So although there are no LEDs on this other fan the noise still existed but didn't matter much at all compared to the first fan that was pretty loud. Now considering removing my magnets from first fan to glue onto second fan, which would mean blue LED in the ferm fridge B)


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## spog

For anyone interested there is a how to build a stirplate in the latest issue of BYO magazine.
It even has pictures .
Cheers....spog..


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## lael

ok... so a while back I posted that I had ordered those Delta 1212AFC server fans. Tried controlling them with an LED dimmer... annoying whine. Got interested in PWM control, and then... hmm 4 pin fan.. get realy PWM control. I didn't know how, so I found a post where people were talking about doing it on overclockers forum.

Long story short - a friend helped to build an awesome controller board. I got frustrated trying to make it work properly. Gave up for a while, ordered something else which didn't work for the fans. Gave me motivation to get it worked out.

Behold the stir monster!




5L being stirred - turns out that straight walled is harder to stir than conical and that glass is easier for the stirbar to stay steady on (no surprise).




There was a post that said faster stirring was better... 




I can't get the large stirbar to go quite fast enough to do this, but with a 1" one the stirbar gets completely enveloped in air. I was scared the stirbar would launch off and break the glass the first few times... but it slows down pretty quickly when it gets launched (the little one can go all the way to 4000rpm... )

So why do you need a big stirplate? - big starter of course! 










Hard to tell how far the vortex goes down. Not that far. The stirbar is kind of noisy in the bottom of the 20L handypail.

Next step... stir a fermenting beer for the first two days?

edited: clarity


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## MastersBrewery

lael said:


> ok... so a while back I posted that I had ordered those Delta 1212AFC server fans. Tried controlling them with an LED dimmer... annoying whine. Got interested in PWM control, and then... hmm 4 pin fan.. get realy PWM control. I didn't know how, so I found a post where people were talking about doing it on overclockers forum.
> 
> Long story short - a friend helped to build an awesome controller board. I got frustrated trying to make it work properly. Gave up for a while, ordered something else which didn't work for the fans. Gave me motivation to get it worked out.
> 
> Behold the stir monster!
> 
> 
> 
> 
> stirmonster01.jpg
> 
> 5L being stirred - turns out that straight walled is harder to stir than conical and that glass is easier for the stirbar to stay steady on (no surprise).
> 
> 
> 
> 
> stirmonster02.jpg
> 
> There was a post that said faster stirring was better...
> 
> 
> 
> 
> stirmonster03.jpg
> 
> I can't get the large stirbar to go quite fast enough to do this, but with a 1" one the stirbar gets completely enveloped in air. I was scared the stirbar would launch off and break the glass the first few times... but it slows down pretty quickly when it gets launched (the little one can go all the way to 4000rpm... )
> 
> So why do you need a big stirplate? - big starter of course!
> 
> 
> 
> 
> stirmonster04.jpg
> 
> 
> 
> 
> stirmonster06.jpg
> 
> 
> 
> 
> stirmonster07.jpg
> 
> Hard to tell how far the vortex goes down. Not that far. The stirbar is kind of noisy in the bottom of the 20L handypail.
> 
> Next step... stir a fermenting beer for the first two days?
> 
> edited: clarity


I'm thinkin a new thread is required!!! Awesome stuff. I'm on my brewing shopping spree ATM, and was seriously just about to go hit up the guys at Digital home brew for some kit.


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## Lord Raja Goomba I

Finally got a whirlpool.

Big two tips I can give.

The bigger Erlenmeyer flasks are more forgiving speed wise. My fan is 1000 rpm and in a tiny flask too powerful.

2Nd bigger one is, test the stir bar sits flat on the magnet. If one side polarises away, then flip the resistant magnet.


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## Lionman

I have noticed there are some 3d printed DIY PC fan stir plate designs on Thingiverse. I might have to print one out.


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## Mardoo

Oooo, good idea. I hadn't thought to check on Thingverse for enclosures.


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## tdog_505

so here is my version of a computer fan stir plate. All up with some scrounged components it cost me about $30... could have saved a couple of dollars by excluding the switch, as the voltage controller has an inbuilt switch, but now i get the external light that shows when its running.

View media item 10943View media item 10944


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## MHB

I just got one of these on eBay, $40 delivered, pretty neat and tidy little unit.
Probably a lot tidier than I would build. good value and a lot less mucking around.
Mark


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## tdog_505

MHB said:


> I just got one of these on eBay, $40 delivered, pretty neat and tidy little unit.
> Probably a lot tidier than I would build. good value and a lot less mucking around.
> Mark
> View attachment 116387


Good deal! All up I would say mine cost more than that, even though I scrounged a few parts! Was kinda fun to make though...


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## MHB

Yep I get that part, I'm in the middle of building a couple for some 1L and 6L Bellco Bioreactors, they only want to turn at 30rpm (Teflon blades the size of your hand) but in the interim I needed a stir plate in a hurry and the above was a good buy.
The ones I'm building have temperature control, timed O2 supply and the stirrer drive, so a bit more complex, designed to propagate enough yeast from 1 Wyeast smack pack up to a 200L pitch
Sort of like this but twice as big - Mark


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