My Stirplate... Cheap and Easy Build...

[joety]

well, they're centered enough that they don't cause the fan to wobble, but I'm sure they are slightly off.

How accurately did you get yours centered and how did you do it? I have a digital micrometer and center-finding calipers. I can see the dimple at the center of the fan hub, but I assume I can't drill through there since the copper windings are inside the hub, right?

I just adjusted by feel until there was no wobble, then cemented down. I have made a few dozen starters since then, and the fan has not burned out yet. Knock on wood.

 

[camiller]

well, they're centered enough that they don't cause the fan to wobble, but I'm sure they are slightly off.

How accurately did you get yours centered and how did you do it? I have a digital micrometer and center-finding calipers. I can see the dimple at the center of the fan hub, but I assume I can't drill through there since the copper windings are inside the hub, right?

How I did it:

1. Start the fan spinning
2. touch a sharpie as near as possible to the center, making a circle slightly smaller than the hole in the fender washer
3. stop the fan and use the spot to line up the washer and glue in place
4. draw a line across the washer and place the magnet(s)
5. put the stir bar directly on the magnets and turn on the fan.
6. viewed from above the center of the stir bar should look like a solid circle the width of the stir bar while the remainder has a kind of blurred appearance. If not adjust accordingly.
7. once it looks centered while spinning, mark the location of the magnets on the washer and remove/glue/replace.

 

[kcreiglow]

Thanks to this post I was able to figure out a few problems I was having with my Stirplate.
First, I couldn't regulate the speed with my potentiometer. I wired it differently using directions from a Utube video.
Second, I kept throwing my magnet. I felt it was due to not being able to regulate the speed of the fan but it was also that I had to many volts powering my fan. I had a 12 volt power supply. When I switched it to a 6 volt it was a perfect combo of speed and power to keep the magnet centered.

Thanks everyone... I love this hobby!

 

[petey_c]

My stirplate Ver. 2.0 passed it's 24 hour QA test. Thanks for all the help. Pete

 

[EllisTX]

Old heatsink fan √
Old hard drive magnet √
Some artsy fartsy box my wife is probably going to kill me for drilling holes in even though it only cost $2 √
A stirbar from ebay √
Lots of good info from this thread √

 

[Gear101]

just got everything to make one of these next week, only thing is that the power switch only has two post on the back of it?

 

[Gear101]

Works like a charm, only think I did different was I bought a fan at Radio Shack and the total bill was still around 32 dollars. The fan I bought was so tight that I had to remove the “ripped” material from inside the box, small sharper chisel, and it came right out. I went to a smaller hardware store and bought bolts that just made it into the holes, and then they “tapped” in with a driver and holds it at perfect height.

 

[Diver165]

That's a Rheostat and power switch in the background. My only regret is that I put the switch in the center of the box instead of moving it to the left to balance out the look of the front of the stirplate. OH well...

I put in a plug for the "wall wart". It looks nice and neat and allowed me to brush up on the soldering skills.

The height of the fan is adjustable. If I find the pull on the maginets is too much I can lower the fan.

2 Neodymium Magnets 3/4 x 1/4 off ebay. These things are insanely strong!

My total cost was about $30. I'm happy with it. It was fun to build and works like a charm! Beats the hell out of buying one for 100.00

 

[good11s]

i gotta do this

 

[Diver165]

i gotta do this

Yes you do. It's a fun and easy project to do. And best of all it saves you a ton over what you can buy elsewhere ready made.

 

[petey_c]

Old heatsink fan √
Old hard drive magnet √
Some artsy fartsy box my wife is probably going to kill me for drilling holes in even though it only cost $2 √
A stirbar from ebay √
Lots of good info from this thread √

Square root?

 

[EllisTX]

Square root?

Damn it. I knew someone was going to catch that.

 

[cincybrewer]

I'm looking to build one of these so does anyone know a cheap place to my the flasks? They seem a bit pricey at the homebrew stores.

 

[Gear101]

Yes you do. It's a fun and easy project to do. And best of all it saves you a ton over what you can buy elsewhere ready made.

It is that easy too, just follow the OP and everything goes together that easy. That coming for some that knows nothing about wiring anything. At the cost of 1/2 to 1/3 the price of a pre-made one, I might make two of them.

Cheers

 

[Diver165]

I'm looking to build one of these so does anyone know a cheap place to my the flasks? They seem a bit pricey at the homebrew stores.

brewmasterswarehouse has 2L ones for 19.99 and 6.99 flat rate shipping. That's about as cheap as I've found them for the 2L version

 

[atjsparty]

Check out Cynmar. Pretty good prices. Found the flasks when I was looking for yeast slanting stuff.

 

[JonGrafto]

My ghetto stir plate with my first starter in a Pyrex decanter I got at goodwill for $0.99

 

[barrooze]

My ghetto stir plate with my first starter in a Pyrex decanter I got at goodwill for $0.99

What size flask is that and what volume starter are you stirring?

 

[JonGrafto]

What size flask is that and what volume starter are you stirring?

It's about a 2L glass. I split my smack pack on half and I am building it up. What's in there is about a liter

 

[FredTheNuke]

www.homebrewstuff.com has stir plates for $42. Based on cost of the parts for the DIY and the value of my time that is a damn good price!!!

 

[JonGrafto]

www.homebrewstuff.com has stir plates for $42. Based on cost of the parts for the DIY and the value of my time that is a damn good price!!!

Cost of parts? All mine were free less $2.00 in bolts. and it took maybe 15 minutes to do.

 

[Diver165]

www.homebrewstuff.com has stir plates for $42. Based on cost of the parts for the DIY and the value of my time that is a damn good price!!!

So I saved 12 bucks. I killed a 6er of homebrew and spent an evening acting like MacGyver in my workshop (making something out of nothing). And best of all, the damned thing works!!

Now if I can make a fermentor out of chewed bubble gum and duct tape. ... Never mind ...

 

[MonkeyMashBrewing]

So I made a stir plate out of a 12v pc fan, hard drive mag and spliced in a power supply. I didn't have a rheostat laying around so rather than spending a few bucks, I used a 5v power supply. Thought being less power, lower speed....

Take a look at the vortex it produces and let me know what you think-

Im no pro but I would say its constantly moving and that's better than the occasional stir a few times a day? This is a 2oz/500ml starter, I think I might not have enough behind it to start a larger batch but I would say this is a good start.

Cheers:

 

[Gear101]

FYI computer repair shops have a TON of old hard drives letting around, I got two hugh earth ags for 3 usd.

 

[rales]

Hey all - virgin post here so be nice...

I actually built this before discovering the forums. I haven't read all of the 100+ pages - but a good chunk of them and didn't see anything like my very simple setup. I was at Fry's for a cheap fan and saw an Antec 3-speed 80mm for $6 and thought I'd try it. Speeds are 1500/2000/2500 rpm with a simple switch. The local RS was out of the 25 ohm rheostats so I thought I'd try it without and see what happened... could always add one later. I knew I wanted the magnets (.475" rare earth) away from the fan and the 1" pvc bushing was the perfect height (about 1.25") for my cigar box with a good surface to mount the magnets. Had some strong double sided tape that allowed me to dial in the spacing before epoxying. Found that 1.125" on center was perfect for my 1" stir bar. If I've learned anything from reading this and other forums/YouTube is that bigger bars = more trouble!

Works great! The 1500 is about perfect for 750 ml in a 1L flask with a vortex bouncing all the way to the bottom and even the 2000/2500 speeds won't throw the bar - I can imagine the higher speeds will work well for larger starters/flasks. Power supply is 12v from an old router. Total of about $8 in parts.

So - no rheostat, no on/off switch... center the bar and plug it in... away you go. Worked beautifully on a stepped starter last week...

 

[befus]

Built one of these this afternoon. Cost $19. Waiting on stir bar to try it out. Thanks for the how to!

 

[Homercidal]

Tested out my new version this week. Building it for a friend. Using a 1.5" stirbar and 4 small round rare earth magnets, and a Homebuilt PWM circuit.

On about as low as I could get it, 1800ml still have a very pronounced vortex. The stirbar rattled badly until I realized the flask was not level to the stirplate. A small shim under one corner fixed that.

There is a small hum from the PWM, but not bad at all. I have it sitting on my desk and I can play games and listen to music without being disturbed. I probably wouldn't prefer to have it next to my bed, but it probably wouldn't keep me from sleeping either.

My thoughts after this experiment is that 1.5" stibar is actually pretty long for a small flask. Where my 3/4" bar does fine, the 1.5" almost seems like overkill. PWM is nice and I like the fine control you get, but my old stirplate work great with just a POT and wall wort.

The magnet alignment seems better on my new version. The bar is held tight throughout the full speed range. I haven't tried it with my 3/4" bar yet, but I expect similar performance.

Next step for testing is putting the 1 gallon jug up there and see how it goes.

 

[Gear101]

I use a 1 inch bar with a 1 liter and it seems to be just about right, so not to make a cake and keep everything moving, but that is at about 1/3 power.

 

[GulfCoastGirl]

Just got mine done last night. A big thanks to everyone who contributed to the thread with advice, pictures and most importantly DIAGRAMS of the wiring.... that was most helpful


Here I've got shots of a 1.5" stir bar in a quart size canning jar on the lowest setting... WAY overkill as it looks like the Tazmanian Devil spun up a tornado in there (is there such a thing as too much spin?).

I have a 1" stir bar on order so hopefully it will be a little more tame.

I put a hole in the back of the box and the side of the box as well to allow for good circulation of air. Don't know if that was needed but it just seemed logical to me to create good air flow around the fan.

 

[Mellow52]

Just got mine done last night. A big thanks to everyone who contributed to the thread with advice, pictures and most importantly DIAGRAMS of the wiring.... that was most helpful

Here I've got shots of a 1.5" stir bar in a quart size canning jar on the lowest setting... WAY overkill as it looks like the Tazmanian Devil spun up a tornado in there (is there such a thing as too much spin?).

I have a 1" stir bar on order so hopefully it will be a little more tame.

You need nothing more than a 1" to 2 " vortex / dimple. The one inch stir bar will help but also get a lager container like a 2000 ml lab flask. The lab flask works well with the stir bar since it has a very flat bottom. Can you slow it any without stalling?