Building a Stir Plate [Science]
2008 Jun 29
Pretty cool Zym. If you do choose to use a potentiometer, just make sure you get one with appropriate heat rating. The ones that can dissipate power are the wirewound potentiometers, and are rated in watts of dissipation. I would expect one of less than 5 watts (maybe less than 1 watt) would be good enough.
2008 Jun 29
That's a fantastic project, and definitely cheaper than buying your own. I bow down to your superior skills!
Make sure the stir bars are cleaned to within an inch of their life before you put them on the production line: you'd never believe the kind of stuff I had to mix when I was doing lab work ;)
Make sure the stir bars are cleaned to within an inch of their life before you put them on the production line: you'd never believe the kind of stuff I had to mix when I was doing lab work ;)
zymurgist
Tonight I finally collected up all the stuff I need to build a stir plate for propagating yeast. If you propagate your yeast with the aid of a stir plate you can actually get about 5x the number of yeast cells from the same amount of wort, as doing it without the stir plate.
I'm roughly using the direction on this page : chris.norrick.com
Though I'm trying it with a DC fan, not an AC one as they use.
I picked up :
- a $2 12V DC fan at princess auto
- a 9V DC adapter from the garbage can at work
- 1" (30lb) rare earth magnets at Lee Valley
- glue dots at lee valley
- stir bar and flask from a friend who works in a lab
I put a quick prototype together this evening, but it's not working and I'm not sure what I'm doing wrong. Off the top of my head I think it might be that the fan is turning too fast. Since it's DC I don't have a potentiometer in the mix. Any electronics whizzes out there know of a cheap DC potentiometer?
Anyway, will update with my progress, if any ...