Mr. No-Tip
Well-Known Member
- Joined
- 26/9/11
- Messages
- 920
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Hey Brewers,
I've been building a home made stir plate this weekend:
-12v PC fan
-12v 500ma PSU
- eBay purchased 'rare earth' magnets
-70mm stirrer bar without pivot
-2l flask
Having a few problems...
The magnets aren't place entirely evenly - they got kind of sucked in by the fan's central magnet while the araldyte was drying. Not perfect now, but still pretty close. I initially found that the bar was throwing no matter what distance I picked. I think I have that figured out - maybe the chinese magnets aren't all they're cracked up to be - stack four of them, and we get a stir.
So now I have my stir, but this is the best whirlpool I can get (starts at 1.5l, topped up to 1.75l before the end...ignore dog and masterchef)
That's nowhere near what I have seen in demo videos. Now I can see the problem - not enough fan torque. As soon as I lift the flask off, the fan goes visibly faster a second later. I suspect the weight of the four magnets and the less than perfect positioning may also contribute.
I did try it with a 1a power supply, but the difference was pretty negligble.
Is that whirlpool sufficient for a 1-2l starter? If not, any suggestions on how to fix?
Thanks!
I've been building a home made stir plate this weekend:
-12v PC fan
-12v 500ma PSU
- eBay purchased 'rare earth' magnets
-70mm stirrer bar without pivot
-2l flask
Having a few problems...
The magnets aren't place entirely evenly - they got kind of sucked in by the fan's central magnet while the araldyte was drying. Not perfect now, but still pretty close. I initially found that the bar was throwing no matter what distance I picked. I think I have that figured out - maybe the chinese magnets aren't all they're cracked up to be - stack four of them, and we get a stir.
So now I have my stir, but this is the best whirlpool I can get (starts at 1.5l, topped up to 1.75l before the end...ignore dog and masterchef)
That's nowhere near what I have seen in demo videos. Now I can see the problem - not enough fan torque. As soon as I lift the flask off, the fan goes visibly faster a second later. I suspect the weight of the four magnets and the less than perfect positioning may also contribute.
I did try it with a 1a power supply, but the difference was pretty negligble.
Is that whirlpool sufficient for a 1-2l starter? If not, any suggestions on how to fix?
Thanks!
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