I found this online article on making your own stir plate and thought someone might like it. Hope it's not a repost. http://makeprojects.com/Project/Homebrew-Stir-Plate/277/1
DIY stir plate
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That's a mighty puny stir plate with only an 80mm fan. He shows it with a mini-sized 250 ml beaker and he only has it filled to the 150ml level. That's like a whopping whole 5 ounces! A 2 liter starter would smother the thing. IMO, the magnets he is suggesting to use are too small, too weak and I have no idea why he suggests using four magnets arranged as he has them. I experimented using four magnets like that one time and it did not work well at all.
I have not seen that particular build before, but there are a gazillion of them floating around including my own. Here's my version using a full 2 liter flask with a 2" stir bar:
These things are very easy to build and many of the parts can be scrounged up for free or very little cost and any parts you might need to buy are not at all expensive.
I have not seen that particular build before, but there are a gazillion of them floating around including my own. Here's my version using a full 2 liter flask with a 2" stir bar:
These things are very easy to build and many of the parts can be scrounged up for free or very little cost and any parts you might need to buy are not at all expensive.
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stamandster
Well-Known Member
That's a great idea, and you can cut off the fan blades if you're at all worried about the fan cooling the yeast.
No need to cut off the fan blades. The moving air is beneficial in that it helps the fan motor run cooler. I don't have to worry about the starter temps much as I keep the house at about 70F year round and the yeast seem to be happy in that range.
stamandster
Well-Known Member
Yeah I was thinking about that earlier and if we were to cut the blades wrong it'd create an imbalance of the rotation.
Here's a electrical parts list at least, especially if you don't have any in your possession.
120mm fan comes with rheostat to control speed -- $8.49
http://www.newegg.com/Product/Produ...1&cm_re=fan_controller-_-35-200-021-_-Product
Molex Power Adapter - $12.49 (if you don't have a power supply you can use)
http://www.newegg.com/Product/Produ...re=molex_power_adapter-_-12-123-309-_-Product
And that's it! Then all you need is a glass/plexi plate, misc bolts and screws.
My present stirplate is about to die, this is interesting as I make large starters.
What magnet/source do you recommend for the fan?
Thanks
What magnet/source do you recommend for the fan?
Thanks
I use two 3/4" X 1/4" rare earth disc magnets from Magcraft:
http://www.magcraft.com/products/disc/disc3.html
I've tested a variety of magnets and these work the best IMO.
http://www.magcraft.com/products/disc/disc3.html
I've tested a variety of magnets and these work the best IMO.
stamandster
Well-Known Member
These ones right? One glued at the center of the fan?
http://www.rare-earth-magnets.com/p-65-nsn0582.aspx
camiller
Well-Known Member
two magnets, one with the north pole up and one with the south pole up, mounted across from each other about the length of your stir bar apart from each other (center to center)
prob not put in the center, most are off to one side or it will stop the motor from turning. I think he is saying two, one on each side, oposite polls facing up so the stir bar will pretty much catch each magnet.
I used one hard drive magnet, off center and I can get a full vortex with a half gal container, as long as the bottom is flat.
I used one hard drive magnet, off center and I can get a full vortex with a half gal container, as long as the bottom is flat.
Yes, those are the ones, but only two magnets are required. No magnet in the center. I've found that spacing them at 1-1/2" center to center works very well with a 2" stir bar. The magnets should opposite poles facing up to match the polarity of the stir bar. I use a wooden disc to insulate the motor from the magnets. Proper magnet spacing, alignment and balance are critical for optimum stir plate operation.
heck yeah that's a killer price for a fan and speed control shipped for free.
-=Jason=-
Here's how I mount the magnets. The disc gets glued to the face of the fan motor:
The wooden disc works as a spacer to move the magnets farther away from the fan motor while providing precisely spaced pockets for the magnets. The disc also works as a flywheel.
The wooden disc works as a spacer to move the magnets farther away from the fan motor while providing precisely spaced pockets for the magnets. The disc also works as a flywheel.
Catt, that is Sweet! nicely done.
Thankx! I've build more than a few of these for my brewing buddies. The design has sort of evolved over a number of years. My quest was for a minimalist, low cost design that would perform well and not be excessively ugly.
stamandster
Well-Known Member
So you used oak? heh... just kidding. I love the "flywheel" idea!
lol...yes, I used oak for that particular one, but I've since switched to poplar. Much easier to work with the poplar, but any clear wood will work. I'm about to put together another one for a buddy. I'll take some step by step pics for more detail on the build.
