Stirplate Parts List

[Leann ull]

Looking good, do a test with an erlenmeyer or demijohn.
You only need to keep the yeast in suspension not make whipped cream.
I really like the digital display

[BrewDorg]

Not much difference in price between that PWM and similar ones with no display so thought sure why not!

I have a 5L Erlenmeyer on the way so can't wait to see how that fares. I have the ingredients for a Rochefort 8 clone here waiting but I can't put it on until I can make a big starter. It's making the anticipation much worse.

[gazz]

I have most of my parts which are
Plastic Box with clip seals - Dealz €1.50 for 2
Fan - Off old computer - Free
Magnet - Off old hard drive - Free
And using one of these plugs, found in most poundshops or more than likely you have one in some draw in the house, cut of the ends and connect the 2 wires to fan wires, use the power switch between 3v-12v to increase/decrease speed of fan

[Leann ull]

Thats what I have and its great

[cruiscinlan]

I have most of my parts which are
Plastic Box with clip seals - Dealz €1.50 for 2
Fan - Off old computer - Free
Magnet - Off old hard drive - Free
And using one of these plugs, found in most poundshops or more than likely you have one in some draw in the house, cut of the ends and connect the 2 wires to fan wires, use the power switch between 3v-12v to increase/decrease speed of fan

Can you get that type plug in pundshop here?  I've never seen one here.

[gazz]

Maybe they are not as popular now with everything using the standard USB chargers, but look about in the cheap shops for em, you could use any old charger Nokia etc but it would be at the one speed. Somebody you know has one of these in the old draw with all the spare bits and bobs that's in every house

[BrewDorg]

I used an old Nokia charger and it turned out to be only 5V. Make sure it's 12V before using it, otherwise it won't spin.

[Oh Crap]

I just completed my stir plate build and I'm very happy with how it went. Still waiting on my erlenmeyer flask before I can put it to proper use though.

Video here: https://www.youtube.com/watch?v=iR9pjS6nQMQ

Parts list:

• Project Box - €4.30
• 12v DC fan - €1.70
• PWM with digital display - €6.35
• Rare earth magnets - €3
• Nuts & bolts for mounting - €3
• 19v laptop charger (!!!) - salvaged

Less than €20 on parts but did spend around another €10 for shipping. It'd be possible to get a cheaper PWM and salvage a hard drive magnet if you really wanted to do this on the cheap but I'm happy with what I've spent.

Only snag I ran into was using a mobile phone charger to power it. I had it all wired up, assuming the charger was 12v. However, only after hot gluing it in place and firing it up, I realised it was only 5v and barely got the smallest bar to move. So, since my PWM was rated for 24v, I thought why not use my 19v laptop charger and just reduce the speed so as not to burn out my fan. The digital display comes in really handy for controlling the speed accurately and I think I'll appreciate the extra length of the laptop cord when leaving it somewhere to stir.


Just a note on the video. I'm using the medium sized bar and it doesn't spin until I crank it up to ~35, but the small bar spins fine at lower speeds. The big bar spins nicely too, even at high speeds.

Fire away with any questions, happy to help if I can.

Let me begin by blaming you.....id stopped making stuff but now I want to make a stir plate...it's all your fault cause this is going to lead to trouble lol😂😂😜😜
Just one question about magnets, what size did you get in the end? 8x2mm? Or bigger smaller
Cheers

[johnrm]

@Brewdorg, can post a pic of your motor/Magnet assembly?

Its the bit that I have found tricky as it needs to be balanced to reduce vibration.

[BrewDorg]

No hassle lads, I'll crack open my stir plate after work and take pics.

@ Oh Crap, I'll happily take the blame for that! I got the 8 x 2 mm magnets and stacked 2 on top of each other.

@ John I just remembered how I got such good placement on the magnets. I had an old hard drive magnet that I glued to the center of the fan first. Then I simply positioned my stacked 8x2mm magnets at either side of that magnet until it spun nicely. They're more than strong enough to stay in position too so I didn't hot glue them. I'll take pics later anyway!

[johnrm]

Something I noticed when attempting to build one of these was the magnets on the fan affected the magnetic field on the fan motor.
The lag you experience at low rpm may be directly related to this.

[BrewDorg]

Something I noticed when attempting to build one of these was the magnets on the fan affected the magnetic field on the fan motor.
The lag you experience at low rpm may be directly related to this.

It more than likely is. The magnets actually stick to the metal through the plastic fan blades. My 19v charger does more than enough to compensate though!

Lot's of DIY stir plates builds have a metal washer glued to the fan and then the magnets stuck to the washer. That would probably prevent the lag due to magnetism too. Although the added weight of the washer would probably mean any gains are negligible!

[johnrm]

Great job BTW!

[Leann ull]

I use a self adhesive metal strip and attach it to the fan then you can adjust the magnets to where you want them

[cruiscinlan]

I use a self adhesive metal strip and attach it to the fan then you can adjust the magnets to where you want them

Where would I get self adhesive metal strips at all?