# Homemade stir plate in progress.



## Kiwifirst (5/6/14)

Found a old PC at work and pulled the fan and hard drive. 
Next step the box and switch.


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## mofox1 (5/6/14)

Thats the spirit, I just hit up ebay. Mindless consumerism at its best.

Still... $1 fan & $2 for some i-can't-pull-these-apart magnets.

Thought I'd get fancy with a bit of perspex for the body (only once I found out how much 3D printing costs - sheesh!) and that was the most expensive bit - $8 for an A4 sheet.

Build yet to come - keep us posted on your progress!

Mick.


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## mofox1 (5/6/14)

Actually - I take that back about the perspex being the expensive bit...

It'll be the farking flasks. I *know* they're worth it, but the anally retentive money monger in me doesn't appreciate it.

Mick


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## mosto (5/6/14)

Just a tip, if you gut the PSU (Power Supply Unit), screw the casing back together and cut a hole in the top, makes a perfect housing for the fan of your stir plate.


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## Kiwifirst (5/6/14)

Hey mofox, I had raided the Tupperware/sandwich box selection in the kitchen and had already cut out a couple of holes when I saw mosto's post. Kind of obvious now when I think about it eh? Thanks Mosto, you're right, I'll go back and raid the box I ripped the fan out of. As I was pulling out fans and hard drives, I originally thought using the ps box might not be good due to if being metal. I guess the magnets are strong enough and close enough to ignore right?


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## Pogierob (5/6/14)

I hope you get a photo of your bosses face when he comes in to work tomorrow and his PC is completely disassembled on his desk..


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## Kiwifirst (6/6/14)

LOL I put the sides back on, he might not notice


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## Mardoo (6/6/14)

"It makes a clunking sound when I shake it."


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## Kiwifirst (17/6/14)

About to try my hand at soldering. It has been a while.


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## Kiwifirst (17/6/14)

I am only using half a magnet and it isn't spinning the stir bar. 
Either it is because I have half a magnet or because I am only using a 9v power output and it should be 12v. Or is a combination of the two?


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## lael (17/6/14)

The stir bar has north at one end and south at the other. You need to have opposite magnets to match. Place them as far apart as your stir bar is long.


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## Kiwifirst (17/6/14)

So I should use the whole magnet and not just half? If I cut out that ragged hole bigger, I could use an entire magnet. Then I'll need to have the space between the two magnets the size of the stir bar length, is that right?


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## lael (18/6/14)

as long as you put the magnets with one with south pole up and the other with north up.


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## zooesk (18/6/14)

lael said:


> as long as you put the magnets with one with south pole up and the other with north up.


+1
I have a 5v phone charger powering my 12v fan works fine


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## Kiwifirst (18/6/14)

One with South up and one with north up? 
I am confused, I have a little whit plastic covered magnet about 20mm long in the flask and a magnet superglued to the top of the fan. Are you saying that maybe I need to flip the magnet on the fan over? Because I can't control the stir bar.


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## MastersBrewery (18/6/14)

You need two magnets on the fan

MB


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## mofox1 (18/6/14)

Like this (shamelessly borrowed from http://www.digitalhomebrew.com/diy-magentic-stirplate-kit):





And as lael mentioned, make sure one's north up and the other is south up. Easiest way to make sure is to stick them together, and when you pull them apart just lay them down so the previously "stuck" sides are up. When you stick them down, make sure the separation is approximately the length of your stir bar (probably 30mm ish?). Too close you won't get a good "grip" on the stir bar, too far apart and you'll throw the bar very quickly (if it even spins).

Hit up google or youtube for stir plate searches... there's quite a lot of people making very functional (and some awesome) stir plates.

Mick


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## lael (18/6/14)

Mick, if you've got any links handy for awesome ones I'd like to see them!


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## zooesk (18/6/14)

Kiwifirst said:


> One with South up and one with north up?
> I am confused, I have a little whit plastic covered magnet about 20mm long in the flask and a magnet superglued to the top of the fan. Are you saying that maybe I need to flip the magnet on the fan over? Because I can't control the stir bar.


The half magnet you have is ether north or a south magnet you need to have the other half so you have north and South then you will be good


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## mofox1 (18/6/14)

zooesk said:


> The half magnet you have is ether north or a south magnet you need to have the other half so you have north and South then you will be good


Lol! If he's got himself a monopole he (or his pole <chortle>) is going to be the interest of a great deal of physicists.



Mick


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## mofox1 (18/6/14)

lael said:


> Mick, if you've got any links handy for awesome ones I'd like to see them!


On the mobile atm, but one of the best I saw was actually through the digital home brew website. 3D printed structure in an offensive orange colour. I liked it and got the same colour in perspex.

Others have used external hdd enclosures, cigar boxes...


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## Kiwifirst (18/6/14)

Lol thanks everyone, it all makes sense now. All I had was the one magnet from a Harddrive, which I broke in half because it was too big for my rough arsed hacksawed hole. 

So I'll prise off the washer with one magnet on, add something larger to sit on the fan and put two magnets on it, north and south. 

When I broke the magnet in half, one part of it flew into a bucket of screws, that was a task getting a ball of screws out of a narrow necked jar


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## Kiwifirst (18/6/14)

MastersBrewery said:


> You need two magnets on the fan
> 
> MB


This seems so obvious now 

Sigh. 

I have intention, enthusiasm and lack the research bit.

Why I thought one magnet would cause the stir bar to spin is....... Interesting.


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## zooesk (18/6/14)

mofox1 said:


> Lol! If he's got himself a monopole he (or his pole ) is going to be the interest of a great deal of physicists.
> 
> 
> 
> Mick


Haha too many drinks go the blues


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## Kiwifirst (21/6/14)

Woohoo it works.

Scavenged, borrowed and built this for free. Bit of blue food colouring in wAter for photo.


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## Kiwifirst (21/6/14)

Attached the photo this time.


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## mofox1 (21/6/14)

Kiwifirst said:


> Attached the photo this time.


Good one... hope my not-so-free one will work just as well 

With any luck I might even do a bit more on it tonight.... (it mostly still looks like the orange pits of plastic on the AHB home page)


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## Pogierob (21/6/14)

Made mine a few months back but when I got the stir bar it wasn't balanced. 
Finally got around to rebalancing it tonight. 

http://youtu.be/E2y4epM01mY


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## Kiwifirst (21/6/14)

Nice. I haven't got that much vortex action going. But I have the same box set up, so I am expecting much more action with a smaller starter. My trail was with 3l. Good to see your video.


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