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General Category => Equipment and Software => Topic started by: dzlater on December 01, 2010, 04:50:08 PM

Title: stir plate alternative?
Post by: dzlater on December 01, 2010, 04:50:08 PM
While watching the BrewMaster teevee show I noticed they had the yeast on these rotating table tops to keep the yeast in suspension. Googling around I found a whole lot of really expensive ones. Something like this seems like it would be easy to build.
A platform mounted on springs on top of a rotating arm. Anyone every tried something like this?
Just thought it was neat idea.
Here is picture I found.
(http://www.noblersport.com/ebayimg/nin/nin1935a.jpg)
Title: Re: stir plate alternative?
Post by: Kaiser on December 01, 2010, 05:08:59 PM
I thought about this since you could easily build something large enough for multiple flasks. However, the mechanics are a bit more complicated than the fan and magnets stir plate designs.

Kai
Title: Re: stir plate alternative?
Post by: richardt on December 01, 2010, 06:01:36 PM
I'm just brainstorming here.  It'd be a good DIY project for those with the tools and means. 

For a multiple flask stirrer, it might work to have one variable-speed motor, two 4-inch wheels (same size, lying on its side), and a belt connecting the two wheels (so the wheels move in sync).  Attach your multiple flask stir plate (wooden or metal board)with its own hub and axle to the 12 o'clock position of each wheel. As the wheels turn (in sync), the board moves in a gentle circle (without any pitch, yaw, or roll).

I'm sure the parts could be found at Harbor Freight or McMaster Carr.
Title: Re: stir plate alternative?
Post by: Kaiser on December 01, 2010, 06:07:31 PM
Richardt, that's a very good idea. I like the simplicity. 

Kai
Title: Re: stir plate alternative?
Post by: a10t2 on December 01, 2010, 06:21:36 PM
Something even easier to build would be a shaker table. They're used in labs all the time. Just a motor with an off-axis weight, and some kind of shock dampening between the table and the base so that the noise doesn't drive you crazy.

At the homebrew scale, the easiest/cheapest thing to do is probably to use an aquarium pump and inline filter.
Title: Re: stir plate alternative?
Post by: roffenburger on December 05, 2010, 03:12:41 AM
Like Sean said, shakers are used all the time in labs. Its really the preferred method for yeast prop, but magnetic stir plates do the job just fine for homebrewers. At work we have several shakers that are heated and cooled. We also use baffled flasks for extra media agitation.
Title: Re: stir plate alternative?
Post by: dzlater on December 29, 2010, 09:53:53 PM
Found this today,  http://openwetware.org/wiki/DIYbio/FAQ/Projects#Bob_Horton.27s_Shaking_Incubator (http://openwetware.org/wiki/DIYbio/FAQ/Projects#Bob_Horton.27s_Shaking_Incubator)
I had one just about finished today, (without the heater) and the turntable belt snapped.  >:(
I was using a wooden box and thought I would use springs instead of the strings
Title: Re: stir plate alternative?
Post by: Kaiser on December 29, 2010, 11:26:31 PM
Using an old record player, that is a neat idea.

I wouldn't use springs thoug. They'll make the position of the shaker plate weight dependent and you may also run into the problem of an uneven shaker plate.

Kai