Three dollar stir plate

[pondochris]

I decided I would build a stir plate from stuff I had lying around the house. Between my basement and garage I managed to source almost 100% of the materials for free

Making a mess...

Dirty old case fan. I found some old magenetic nametag backs and popped off the magenets. Superglued them to the fan.

Old Motorola RAZR 5v charger.

Guitar volume and tone knob I had laying in my tool box. I wanted to use one of these for fan-speed control but 500k ohms is too much resistance.

Testing out the things.

I found some wood and some masonite wall board and made some ugly cuts.

Fan cleaned and box coming together.

The only part I purchased was the switch for $3

All wired up and working

Isn't she pretty?

The entire project took about a week of tinkering whenever I had time. I purchased the 1L flask and stir bar from my LHBS for about $20 with my 3 dollar stir plate I guess it could be called a 23 dollar yeast propagation platform. My flask has a slightly mounded bottom so I have to move it a little to find a quiet spot for the stir bar.

 

[bobeer]

nicely done!

 

[cixelsyd]

Booo, guitar pots won't work for this! Booo! Actually, I may have one of the 25K pots from an EMG active setup... Any way to math that out or just try it?

 

[NewBrewB]

I like knowing that there is a really entrancing blue glow inside the box, even if we can't see it.

 

[pondochris]

Booo, guitar pots won't work for this! Booo! Actually, I may have one of the 25K pots from an EMG active setup... Any way to math that out or just try it?

I'd just try it and see. I tried mine. With the knob all the way on the fan ran at full speed but turning it down just the tiniest amount turned off the fan. If it works it works, the only thing you'd need to keep an eye on is that it doesn't get too hot I think. I don't have much experience working with electricity unfortunately.

I tried a 12v power adapter but it was way to fast to keep the magnet. I like the speed I get with the 5v even without fan control.

 

[cixelsyd]

Yeah I figured out that even 25K is still way too much resistance, being as the fan itself is only a load of about 30 ohms. V=IR