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 ******* 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.

 

[Bizier]

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.

No, diagram is assuming grouped magnets are of same polarity. Sorry, I meant to put it there but I did it very quickly.

 

[captaincleanoff]

can anyone tell me if the stir bars without the pivot in the middle are quieter?

I got a stir bar with a pivot in the middle, but it is really noisy when using the stir plate. I borrowed professional stir plate from work, so its not because I have a dodge plate design.

i think I read somewhere in this thread that the stir bars without the pivot are quieter.. Can anyone confirm before I go out and buy one?

 

[porky]

can anyone tell me if the stir bars without the pivot in the middle are quieter?

I got a stir bar with a pivot in the middle, but it is really noisy when using the stir plate. I borrowed professional stir plate from work, so its not because I have a dodge plate design.

i think I read somewhere in this thread that the stir bars without the pivot are quieter.. Can anyone confirm before I go out and buy one?

Yes they are, as it has been pointed out many times before.
A flat bottomed flask is the most important part for a quite operation, along with a stir bar without the middle pivot.

 

[captaincleanoff]

Yes they are, as it has been pointed out many times before.

thanks for the smartass response.. I didnt particularly want to look through 26 pages.

edit: ****** label by the way

 

[wakkatoo]

thanks for the smartass response.

I agree, was a pretty simple question really. I've read all 26 pages at various times and no doubt it is in there somewhere but I've managed to miss it. Now I've learnt something new as well, so thanks for asking (despite the tone of the answer).

 

[Batz]

I buy a few things from this Kiwi site,this looks like it would make building a stir plate a snap if you don't already have one

http://www.trademe.co.nz/a.aspx?id=212232576

I haven't seen them in Australia.

Batz

 

[pdilley]

I buy a few things from this Kiwi site,this looks like it would make building a stir plate a snap if you don't already have one

http://www.trademe.co.nz/a.aspx?id=212232576

I haven't seen them in Australia.

Batz

Sorry Batz, wrong Triac design in that. Its a light dimmer not a Fan Controller. I already checked it out

I ended up with a proper Fan Controller AC Triac circuit from the local Bunnings for my AC fan stir plate design.

 

[Batz]

I ended up with a proper Fan Controller AC Triac circuit from the local Bunnings for my AC fan stir plate design.

That's what I have had for years as well,just found this thing and it sounded good by the dudes rave. (Will control most small AC motors like engravers and fans, exhaust fans etc, up to 300Watts)

Batz

 

[Sammus]

I disagree, I went on the advice to get ones without pivot rings and they just rattle and roll around on the glass. If you tune the speed right and use the right size bar, the pivot ring is the only thing that touches and its dead silent except for the swooshing of the liquid. I couldn't get this to happen without a pivot ring.

 

[pdilley]

That's what I have had for years as well,just found this thing and it sounded good by the dudes rave. (Will control most small AC motors like engravers and fans, exhaust fans etc, up to 300Watts)

Batz

It will work, but not as well as a Fan Controlling Triac circuit and some stress out fan motors more than a Shaded Pole Fan Controller Triac circuit would.... That said I ran my original AC fan glove box design on a light dimmer for a while, though it did get pretty toasty

Light Dimmer (Solid state phase angle firing of a triac) usually will not come with a minimum level adjustment control (this is important for fan motors). Solid state controls are real sensitive to line voltage and differences in load variations. If the voltage jumps around because of the air conditioner kicking on, etc. or flipping on or off a lamp on the same branch circuit that you are running your FAN controlled by a Light Dimmer triac controller, it may cause the dimmer to kick off, or worse, half cycle which sends half wave rectified DC to your AC motor....Not Good...Toast. (Ever notice how they say on the package "for incandescent use only"?) (Light bulbs don't care what you feed them they just average the power).

When you start a dimmer on high, then reduce the speed, you can go to a lower setting, than if you started the dimmer at the lowest setting and increased it slowly, it would start running abruptly at a higher speed. It's kind of like the flywheel effect in that the motor windings kick some voltage back to the dimmer that helps to keep "triggering" it. (If that makes any sense.) If the motor is not running initially, it takes more to trigger it. This is probably why you will notice, like I did when I used light dimmers you have to gun the buggary out of the control to kick start the AC Fan going before you can back it off. Its not a linear control either, so your adjustment ability is hampered if that ever is a concern (wasn't at the time when I first needed a control capability for my first AC fan project.)

The price for a Light Dimmer circuit is usually 1/2 of the price of a Fan Controller circuit when it comes to retail checkout time.


Fan Controller (Solid state phase angle firing of a triac with additional needed components for inductive load (motor) operation) I've seen them with a rotary switch or a slider control. They always turn on at high speed and then adjust to slow. Good ones have a minimum speed adjustment. (If they don't have a min. speed adjustment they don't go very slow.) (Get one with a user settable minimum speed adjustment) No solid state dimmer operates real well at real low speeds. These controls are quite efficient for AC Fan Motor operation.

The price for a Fan Controller circuit is usually double the price of a Light Dimmer circuit when it comes to retail checkout time.

Other options are: Rheostats which are the least efficient control. Variac, Powerstat which are very efficient its just that they cost the most and are huge and heavy and bulky.

Variac -> Fan Controller -> Capacitive De-Hummer (worst for variable speed, you usually get only 3).

Thats all that is best for Shaded Pole AC Motor control. Out for potential damage, and inefficiency would be Rheostat -> Light Dimmer.