Tight Arse Stir Plate

[bonk]

i built one of these and it seems to work a treat, i need a bigger stir bar however as the bloke at the medical supply shop only had a 20mm bar.

the funny part was, as i was paying for them, he explained that he ordered in some other bars, but the guy went to jail for growing dope.... i wonder what he was up to..

 

[ausdb]

I need to chip in here with my effort, I found an old fashioned industrial strength 5-1/4" floppy disc drive up at the local tip/recycling centre a few weeks back. The lady didn't like my offer of $2 so it cost me $5 but I wasn't complaining.

I went home and took it apart and ended up with two of these!


I just superglued two neodmyium magnets to the little flywheel and sit a piece of plastic on top or if I am worried about overflowing with krausen then I use a tupperware container like this picture.


I originally tried to re use the power supply from the hard drive but it only went for about 1/2 an hour before the smoke decided to escape from one of the capacitors, so now I just use a 12V plugpack.

I made a 2L starter which I pitched into 40L of oxygenated 1.053 wort, it fermented out in about 8 days so I was pretty happy

 

[Jye]

Here is my effort from last night, I used Gulf Brewerys article on how to build one with the exception of a few resistors in series to handle the 20V power supply I am using. The magnets came from jaycar and look like they were made for the job

 

[Ross]

First toy for the new year

Built it this afternoon, based on Jye's & Sosmans units.





Bought all the parts from Jaycar - cost $75 all up...


cheers Ross

 

[AndrewQLD]

top stuff Ross, You will have starters with 2x the yeast in 2 days. Best thing I ever made, big thanks to Sosman.

Cheers
Andrew

 

[Zwickel]

Hello Brewmates,

this is a manual how to build a magnetic stirrer, unfortunately written in german, but the pictures tells it all:
http://www.experimentalchemie.de/versuch-057.htm

... and here some variations:

have fun

 

[ausdb]

this is a manual how to build a magnetic stirrer, unfortunately written in german, but the pictures tells it all:
http://www.experimentalchemie.de/versuch-057.htm
have fun

Great link Zwickel :beerbang:

Google is your friend too for translation
http://www.google.com.au/language_tools?hl=en

 

[Jye]

Nice one Ross.

Cheers to better hydrated polyclar

 

[timmy]

Here's my effort.

The fan is from a decommissioned UPS. It's a 240v 45w 180mm. Has no trouble stirring anything!

speed is controlled via a 200va dimmer switch. Just need to be carefull about the speed, it will happily rev to over 2000rpm but not before throwing the stir bar. For this reason i ditched the 15mmx7mm magnets for the 12x5 ones. At about $2 each for the magnets i bought a couple of sizes.

 

[Trough Lolly]

Here is my effort from last night, I used Gulf Brewerys article on how to build one with the exception of a few resistors in series to handle the 20V power supply I am using. The magnets came from jaycar and look like they were made for the job
View attachment 4277

[post="82254"][/post]​

Nice work Jye - I'm about to build my stirrer based on Fitzy's prototype too! I've gotta give my new 2L flask something to do, eh?!
Regarding the middle piccy (retained in above quote), it looks like you've reverse mounted the fan and magnet (nice fat one too!) in the case or did you flip the fan for the photo???
Correct me if I'm wrong, but your mounting method for the fan means we don't have to mess around with metal brackets and we can just stuff some spacers under the fan to raise the fan in the case so the magnet sits nice and close to the topside when you seal the case?

Cheers,
TL

 

[Jye]

Hey TL, the fan is mounted just like in the pic, I screwed it directly to the bottom of the case with no spacers underneath. IIRC when the lid is on the magnet sits about 10mm away and I found this to be close enough to turn the other magnet easily.

I can take another pic showing the mounting better tonight if that will help.

Cheers
Jye

 

[Trough Lolly]

Thanks Jye,
That's a pretty chunky lookin magnet you have there - and I'm not referring to the image in your signature block! :blink:
I'm gonna follow your design lead on this version and mount the fan as you have - I'm too lazy to get some metal and cut it into brackets when I can just stuff some scrap strips of timber under the fan if it needs to be raised closer to the underside of the case cover.
If you're gonna take a pic (and thanks if you do) could you also do a close-up or two of the wiring between the fan / pot and bulkhead power connector - that'd further reduce the chance of me running 12VDC through my body! h34r: I'll use a 12VDC 500mA power supply so I won't bother with any resistors. By the way, did you solder all the connections? I don't have a soldering iron (yet) but if this job can be done without spending extra bucks on a 40W iron, that'd be good...

Cheers,
TL the heavily overspent household budget brewer!! :unsure:

 

[Jye]

I will post some close ups tomorrow. The 12V supply is perfect, I had a 20V hanging around so I needed the resistors to bring the voltage down a bit and I used a few in parallel because I didnt have to correct wattage ones <_<

You should be able to wire it up the same as in the Peter Fitzsimons article without a soldering iron, just twist the wires tightly onto the jack and potentiometer. These magnets really are perfect for a stir plate and dead easy to centre with some 5 min epoxy, I just turned my fan on low and it centred it self.

 

[Ross]

That's a pretty chunky lookin magnet you have there - and I'm not referring to the image in your signature block! :blink:

[post="127282"][/post]​

TL,

I built mine the same, it works great. I can thoroughly recommend these chunky magnets, they are sold as pairs & are self centering - also being oval shaped they spin really easily even when the flask bottom isn't flat. I mix my polyclar in a kitchen plastic beaker using it, with no worries.

Cheers Ross

 

[Jye]

And they make a cool noise when you use them for their original purpose.

 

[Doogiechap]

So Ross and Jye, am I correct you use the second magnet as the stir bar ? The tight arse im me is coming out bigtime here but it is in mortal combat with the thoughts of the magnet leeching 'nasties into the starter :blink: . Any thoughts ?
Cheers
Doug

 

[Jye]

So Ross and Jye, am I correct you use the second magnet as the stir bar ? The tight arse im me is coming out bigtime here but it is in mortal combat with the thoughts of the magnet leeching 'nasties into the starter :blink: . Any thoughts ?
Cheers
Doug

[post="127296"][/post]​

Yep the second one is the stir bar and I had the same concern when I first got them so I did a test starter. I couldnt detect anything wrong with the starter using my great sense of smell and taste :blink: and the magnet didnt show any signs of corrosion. The surface isnt like a bar magnet, it has a smooth protective coating which make it easy to clean with napisan or what ever. After a dozen or so starters and using it hydrate polyclar it has no signs of wear and tear.

 

[Ross]

So Ross and Jye, am I correct you use the second magnet as the stir bar ? The tight arse im me is coming out bigtime here but it is in mortal combat with the thoughts of the magnet leeching 'nasties into the starter :blink: . Any thoughts ?
Cheers
Doug

[post="127296"][/post]​

As Jye say's it's showing no signs of wear & I'm not aware of anything toxic in a magnet, but no doubt someone will enlighten us if there is a potential risk :unsure: .

++

Notice you're using my wit recipe Doggiechap, let me know what you think - My keg ran out a few days ago & it's going straight back on the list of beers to brew...

Cheers Ross

 

[Pumpy]

What sort of stir bars do you use on the heavy concave bottomed jars this type


Pumpy

 

[Jye]

TL, a few close ups for you.