How to build a stir plate for less than ten quid

Help Support The HomeBrew Forum:

Drunkula

Landlord.
Joined
Nov 30, 2017
Messages
2,197
Reaction score
1,784
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

Regular.
Supporting Member
Joined
Mar 22, 2019
Messages
337
Reaction score
65
It goes really fast when connected direct to power cable. So it is the regulator.
 

yumbeer

New Member
Joined
Jun 19, 2017
Messages
4
Reaction score
2
Location
NULL
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

Regular.
Joined
Jul 21, 2018
Messages
204
Reaction score
43
Location
Bromsgrove
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

New Member
Joined
Jun 19, 2017
Messages
4
Reaction score
2
Location
NULL
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.
 

johncrobinson

Landlord.
Joined
Sep 13, 2019
Messages
1,056
Reaction score
334
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

Landlord.
Joined
Sep 13, 2019
Messages
1,056
Reaction score
334
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

Mint Choc Chipster
Joined
May 20, 2015
Messages
1,627
Reaction score
783
Location
Dundee
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.
 

Latest posts

Top