Diy Computer-fan Stir-plate Build

[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]

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]

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.

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]

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]

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]

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.