DIY Fail...

[atoughram]

The only reason I bought a stir plate was so that I'd only have to buy one tube of yeast instead of two.

Washing and storing yeast - in my opinion - add's complexity and another failure avenue to my process - I'll just buy new yeast every time except when I'm going to pitch the same yeast into different worts - which I do with WLP001. Then I'll pump new wort onto an existing yeast cake.

BUT - I'm not criticizing those who wash, store and re-propagate yeast - each to their own.

 

[monkeeroot]

The point of my latter posts are this: I don't try and DIY a auto transmission rebuild - I've taken everyone I've had to do to a shop. Why? Because I don't have the knowledge, skills, abilities, or tools to do the job and for me to obtain all that, it would cost more than it does to just have someone else do it.

Not too sure how an auto transmission relates to this situation at all. If you do something wrong with a transmission you are risking your life and the life of others. If you do something wrong with a stir plate you basically just run the risk of having less yeast to pitch. I don't believe that any person on this forum started brewing with expert knowledge and equipment. We all took the plunge and learned how to do it.

I have the knowledge, skills, abilities, and tools to build my own stir plate - but I didn't - because my time is worth money to me and it was cheaper to buy it.

That was a decision that you made. You don't know what he has lying around the house that will make building one much less expensive. I built mine for $2.00 because I had almost everything in my garage for example.

Making your own stir plate is cool - but when it turns out dangerous - it's not cool.

I don't think that there are many situations where people have died from 12VDC. There is a much greater risk of being injured while handling several gallons of boiling liquid and we all take that risk.

I'm not too sure why this post has even gone off topic in the first place. The main purpose of this post was someone asking for help with a DIY build. There was never the question as to whether or not he should buy or build one.
Encouraging someone not to try something because you wouldn't do it is not what this forum is about.

 

[toddnaud]

this guy's site, along with the links he posted at the bottom of his blog, helped me:
http://biohazardbrewery.wordpress.com/instruments/brewery-stirplate/

 

[atoughram]

I don't think that there are many situations where people have died from 12VDC.

Probably why we dont see many electrical fires in automobiles...

and I was encouraging the OP to do the safe thing - and get help or buy one already made, no matter what you may believe, 12Vdc will burn your house down just the same as 120Vac.

 

[monkeeroot]

Probably why we dont see many electrical fires in automobiles...

and I was encouraging the OP to do the safe thing - and get help or buy one already made, no matter what you may believe, 12Vdc will burn your house down just the same as 120Vac.

I stand corrected. But, this is why seeking help for projects will help prevent this sort of mishap.

 

[IslandLizard]

I brewed today , laid yeast on water for 15mins , stir a bit for 15 mins , pitched the yeast, air lock going in 2.5 hours. Stir plate ?

That's dry yeast, the cell count is quite high already when re-hydrated properly, and the yeast is ready to take off. Now 2.5 hours must be a new record, never seen or heard that before.

For liquid yeast, the stir plate is a real gem and a reasonable necessity.

 

[kgx2]

Success! Sort of...

So i got it all together and running thanks to the advice and diagram. I learned how to tell the positive side of a capacitor in the process which is always a plus to learn something new! Tested it with my 1L flask and some water and it worked well. Not a lot of speed control but enough. Guess the fan isn't very good?

I say sort of because i pit my first starter on the plate last night and the bar rattles like crazy even though with just water it was fine. I'm guessing stronger magnets are needed to stabilize the bar?

Here's a pic of the finished product in action.

 

[tracyk]

Congrats on your success!! I have made several stir plates for myself and friends and here is what I have found that works best for the ones that I made. An old 80mm computer fan, of course your switch (12v), a 25 ohm 3watt pot (from rat shack), and usually a 6 volt 500Ma power supply. I found that a 300Ma power supply would work, but they were more finicky to get right. With a 6V 500Ma power supply I can do as little as 1 liter up to 5 liters without any problem. With the 1 liter I have the pot turned all the way down. I usually am stirring a 2 liter starter.

If you are using an old hard drive magnet or rare earth magnets those would be strong enough.

 

[abeasst]

Success! Sort of...

So i got it all together and running thanks to the advice and diagram. I learned how to tell the positive side of a capacitor in the process which is always a plus to learn something new! Tested it with my 1L flask and some water and it worked well. Not a lot of speed control but enough. Guess the fan isn't very good?

I say sort of because i pit my first starter on the plate last night and the bar rattles like crazy even though with just water it was fine. I'm guessing stronger magnets are needed to stabilize the bar?

Here's a pic of the finished product in action.

Make sure you bring the sitr plate up to speed slowly. Don't just crank it all the way to high as sometimes this can cause the stir bar to just vibrate and not actually spin.

 

[kgx2]

Yeah i tried doing both and adjusting the flask on the plate but the bat still rattles like crazy.

 

[atoughram]

Congratulations!

 

[IrregularPulse]

Thanks for the links but why would I buy a stir plate when I'm talking about making one in the DIY section?

Because after fighting with one and getting it to spin right and not throw the bar every 5 seconds, it's what you'll eventually end up doing I built one myself and it worked ok for a while, but was always a pain. If I get back into brewing, I'll just buy one for $50.

But congrats on getting it working. As far as not much speed adjustability, that's due to the size of your pot. Not a big enough range of resistance.
Did you try it out in just water first to watch the stir bar? I assume so. What kind of motion were you getting? Spinning or rattling or..? What kind of vortex were you pulling down?

 

[kgx2]

With water the bar was fine and the vortex went top to near the bar with no rattle just a swirling noise. That's why i think i need more magnets to help with the thicker liquid.

 

[atoughram]

With water the bar was fine and the vortex went top to near the bar with no rattle just a swirling noise. That's why i think i need more magnets to help with the thicker liquid.

My prebuilt unit rattles too - I think its an issue with the bottom of the flask more than the stirrer itself.

 

[atoughram]

Double post...

Flash sucks..