Tight Arse Stir Plate

[haysie]

Thx Folks,
I sorted it with the big washer on the hub (50mm) and the rare earth magnets just on the outside of this, 30 mm stir bar ex G&G, i get a nice vortex initially going a little hard then crank it right back. I spun a new 1084 the other night dusk til dawn on 1.5 ltrs and in the morning had a lovely krausen, switched off. Later in the day there wasnt a lot of activity so cranked it up again for a further 2 hours. This morning I had a half inch bowl of yeast, no different to my previous method of shake rattle and roll (always temp controlled). I have seen the charts re. yeast counts, stirrer vrs shaken vrs oxy but i am not convinced the stirrer provides more good yeast vrs dead yeast therefore attentuation issues as per an earlier post/experiment by sosman in this thread.
I turned it off after reaching krausen thinking oxidation, but not thinking too good because i will be pouring off all liquid and resuspending with some cooled, boiled anyhow.My thoughts eliminating oxi factor?
Is there a specific method I have missed re, "more yeast per ltr of wort".
Maybe just another piece of kit , but gotta try new tricks........ or just too bloody goddamn ignorant to stick with what i know.
Thx again. Haysie

edit, i am running this off an old exchange battery 12volt in my shed, i stick it on one of those 12v dick smith jobbies...... nothing??
it was made per LC`s latest

 

[razz]

I'm just spinning my latest yeast for the first time in a couple of years Haysie. I never looked at it from a larger amount of yeast point of view, I've always done it (stirrer) to get there quicker.

 

[haysie]

I've always done it to get there quicker.

The joys of cut n paste.Done what?
I hear you Razz but you can get there nearly as quick with a bit less and stepped up again and again yada yada. Only a newbie this stir thingy, take me with a grain of malt.

edit, dead yeast cells, i do think the stirrer creates more only on my thoughts alone, not backing it up with any tried n true tested methods, but i will be able too tell via attentuation and taste of my beers vrs current method i use

 

[razz]

I think I was sold when I read the the online doc by MB Raines Phd

 

[captaincleanoff]

is it really necessary to have the switch and pot when constructing a stir plate?

Could I just wire the fan directly to a 12V power supply, and not worry about the switch and pot?

 

[schooey]

No speed control, dude... Never a good thing

 

[Fourstar]

Im 1/2 way thru setting up mine, i coundt find the pot at dick smith so i will have to goto jaycar. ive got mine connected to a 7.5V 450mA VDC PSU. Spins up quite well and gets a hex drill bit spinning ontop of the case beautifully.

I'm using a HDD magnet which is quite thin, apoorx 1mm. so ive stuck both of them together. is it best to stack the HDD ones or offset them like the standard rare earths? The magnets from a hdd seem strange when trying to offset them as 1 face does not seem to be a poloar side but center to edge is north and center to edge is south. flip it over and the same applies. Maybe i should just rip apart another old HDD and hope for a fatter magnet.

 

[samhighley]

is it really necessary to have the switch and pot when constructing a stir plate?
Could I just wire the fan directly to a 12V power supply, and not worry about the switch and pot?

This will never work. I very rarely run my fan at full speed, as the magnet just won't work at full speed.

Also, I usually need to start slow and ramp up the speed gradually, otherwise the fan spins too fast for the magnet, and they disengage each other.

Short answer: no, it will not work without speed control.

 

[litre_o_cola]

Im 1/2 way thru setting up mine, i coundt find the pot at dick smith so i will have to goto jaycar. ive got mine connected to a 7.5V 450mA VDC PSU. Spins up quite well and gets a hex drill bit spinning ontop of the case beautifully.

I'm using a HDD magnet which is quite thin, apoorx 1mm. so ive stuck both of them together. is it best to stack the HDD ones or offset them like the standard rare earths? The magnets from a hdd seem strange when trying to offset them as 1 face does not seem to be a poloar side but center to edge is north and center to edge is south. flip it over and the same applies. Maybe i should just rip apart another old HDD and hope for a fatter magnet.

I found that it is important to have that "polar" advantage otherwise the stir bar can stand on one end and be less efficient, that is why I opted for two rare earth magnets with the opposed polarity and it made a massive difference in bar stability. The only time it goes nuts now is at full power and the cavitation from the whirlpool engages the bar.

 

[Fourstar]

Interesting to know. I been planning on getting some rare earth magnets from dealextreme.com maybe this is the excuse to get them... and a LED torch, some hop scales and a LED piggy keychain!

 

[litre_o_cola]

Interesting to know. I been planning on getting some rare earth magnets from dealextreme.com maybe this is the excuse to get them... and a LED torch, some hop scales and a LED piggy keychain!

In the interest of saving on postage of course

 

[captaincleanoff]

is there a cheap alternative to the erlenmyer flasks? I'm going to need a size of about 5L, and a flat bottom for use with the stir plate. Can't think where else I could get a suitable glass container.. any ideas?

Got mine working today! Haven't got a stir bar yet, but it was stirring 2L fine just with a small nail. Very noisy though. Hopefully a proper stir bar will be quieter

 

[Fourstar]

is there a cheap alternative to the erlenmyer flasks? I'm going to need a size of about 5L, and a flat bottom for use with the stir plate. Can't think where else I could get a suitable glass container.. any ideas?

Got mine working today! Haven't got a stir bar yet, but it was stirring 2L fine just with a small nail. Very noisy though. Hopefully a proper stir bar will be quieter

Why do you need a 5L? why dont you just do step ups in a 2L erlenmyer flask to say 1L, crashchill, decant and transfer to 1L of wort in antoher 2L flask?

I get away with doing stepups from a slant via 2 1L erlenmyer flasks. i would prefer a 1L and a 2L just ot make it easier though but 3-4days of growing the yeast i can have enough to pitch into a standard batch, another 2 days and i can attack a high gravity wort!

 

[captaincleanoff]

Why do you need a 5L? why dont you just do step ups in a 2L erlenmyer flask to say 1L, crashchill, decant and transfer to 1L of wort in antoher 2L flask?

because I am doing starters for 65L batches, so I'm going to need to build it up to a bit

 

[~MikE]

because I am doing starters for 65L batches, so I'm going to need to build it up to a bit

i'm currently working on something, based on a 5.5L cookey jar i got at 'the general trader' - not a very flat bottom though- otherwise i was considering a 5L borosilicate beaker from pro-sci-tech - $50 delivered. i figure some silicone bakeware to seal a bastardised chopping board that will make for a lid and clamping ring...

 

[captaincleanoff]

cookie jar would be ok.. except it would need a flat bottom..

anyone else got any ideas what I could use for a 5L starter vessel, before I spend $100 on a erlenmyer 5l flask?

 

[Juddy]

Hello fellow brewers!

I have read with great interest both this thread and most others that are related to all things stirplate. Firstly I would freely admit that I am in no way electronically or electrically minded and can only talk of my own expirience. About two years ago I was convinced that a stirplate was the next gadget that was "essential" in my ever growing home brewery. I researched, and then I shopped! I ended up with a 12v computer fan $25, and a 12v 1 amp plug pack $25 from Jaycar, and some magnets from an old hard drive! Then, as recomended by the friendly if somewhat disinterested people at Jaycar I assempled the main components as shown below:~
The fan attached to a box made of scrap wood from the workshop. Fan attached to plug pack via twisted wire and some heat shrink!

The power pack looks like this.

And when I want the fan to go slow I set the voltage low! And then use the convinient slide switch to up the voltage and hence up the fan speed!
When combined I am able to adjust the speed of the stir bar from next to nothing, too she's gonna blow speed!


Now I have the horrible feeling that I am going to be told that I have done a dreadful thing and I am lucky to have survived tha last 2 years and countless brews! But my set up is this simple, and it works a treat!

And the stirplate, and more importantly me are still in great shape!

So if you have decided that a stirplate is the next "essential" item in your brewery, I believe that $50, some old timber and a scrap hard drive will see you right! It may not be as tight as some stirplates, but it is still one of the cheapest brewing gadgets that I've bought and the results are spectacular! :icon_cheers:

Cheers

Juddy

 

[raven19]

Juddy, another great effort on stir plates.

Gotta get me one... one day.

Well done. Beers!!

 

[Bizier]

I have half built one of these.

I used an standard intel p4 fan and snapped off all of the blades and filed them back. I glued a mini CD onto the mobile part, and it is uncanny, there is about 1mm between it and the circular outer structure.

I currently have 2 magnets on there, and I want to know if anyone can say whether I am better with 4. And if so, do I place these diagonally opposite at the same diameter rather than "outside" the exising diameter?

 

[litre_o_cola]

Bizier, in that diagram does the red and white denote polarity?
If so that would disrupt the stir bar stability, as to the other question having them outside of the existing would enable you to use a longer bar.