How to build a stir plate for less than ten quid

[Justin Dean]

I will try a 1.8v -> 12v one instead

 

[Drunkula]

I can't make out the readings on the meter. And have you tested the power supply directly? And does the fan go really, really fast when just connected to the power supply?

 

[Justin Dean]

It goes really fast when connected direct to power cable. So it is the regulator.

 

[yumbeer]

I've built one of these using this Potentiometer:
https://www.ebay.co.uk/itm/DC-Motor-1-8V-3V-5V-6V-12V-PWM-Speed-Controller-2A-Potentiometer-Knob-Switch-SF/362720085707?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

When I connect it to the fan, it doesn't turn unless I turn it up to full power, and this is a bit too strong to keep the stirbar centred. I have tried both of the following fans with the same result:

https://www.ebay.co.uk/itm/92-x-92-x-25mm-DC-12V-2Pin-65-01CFM-Computer-Case-CPU-Cooler-Cooling-Fan-K4-O7C0/283440840478?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

https://www.ebay.co.uk/itm/90-x-25mm-9025-2pin-12V-DC-Brushless-PC-Case-CPU-Cooler-Cooling-Fan-V1L4-X7-H5X4/302933311172?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Any ideas? It has a light on the Potentiometer and this changes as you turn the knob so it appears to be working. If I reverse the polarity of the fan it never turns.

Cheers!

 

[pottsworth]

I've built one of these using this Potentiometer:
https://www.ebay.co.uk/itm/DC-Motor-1-8V-3V-5V-6V-12V-PWM-Speed-Controller-2A-Potentiometer-Knob-Switch-SF/362720085707?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

When I connect it to the fan, it doesn't turn unless I turn it up to full power, and this is a bit too strong to keep the stirbar centred. I have tried both of the following fans with the same result:

https://www.ebay.co.uk/itm/92-x-92-x-25mm-DC-12V-2Pin-65-01CFM-Computer-Case-CPU-Cooler-Cooling-Fan-K4-O7C0/283440840478?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

https://www.ebay.co.uk/itm/90-x-25mm-9025-2pin-12V-DC-Brushless-PC-Case-CPU-Cooler-Cooling-Fan-V1L4-X7-H5X4/302933311172?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

Any ideas? It has a light on the Potentiometer and this changes as you turn the knob so it appears to be working. If I reverse the polarity of the fan it never turns.

Cheers!

mine is similar in that you have to turn it all the way up to get it moving, but as soon as you get that initial movement you can turn it back down before the speed gets too high.

 

[yumbeer]

mine is similar in that you have to turn it all the way up to get it moving, but as soon as you get that initial movement you can turn it back down before the speed gets too high.

Yeah, I've tried that loads with both fans and it's always off or too fast. Thanks though.

 

[BeerOclock]

I used this PWM dimmer and removed the board.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/311976651711

 

[BeerCat]

For anyone struggling with the bits you can buy these all ready to go with a display and on/off button.

 

[johncrobinson]

I myself would love a stir plate my local homebrew shop dont sell them.
I have many computer fans,So this might become a project over the oncoming long,long Scottish winter months.

 

[johncrobinson]

For those writing about having to start at full power and then turn down.! This is NOT a fault its just the physics of electric motors (of the type used in these computer fans).
stir plates are awsome for yeast farming.

 

[Brew_DD2]

I myself would love a stir plate my local homebrew shop dont sell them.
I have many computer fans,So this might become a project over the oncoming long,long Scottish winter months.

I was going to build one, but after having a quick look on eBay I picked one up for £22.