My shamelessly cheap $12 DIY stir plate

[theCougfan97]

So is the flask necessary/worth $15 for a 1L? Or can I use a mason jar?

 

[mjap52]

So is the flask necessary/worth $15 for a 1L? Or can I use a mason jar?

It depends. If you can get your stir bar to balance and not get thrown off of the center, then you don't need it. I personally think it's worth it. Also, spring for the 2 liter if you do, less steps if you ever need to make a lager.

 

[theCougfan97]

It depends. If you can get your stir bar to balance and not get thrown off of the center, then you don't need it. I personally think it's worth it. Also, spring for the 2 liter if you do, less steps if you ever need to make a lager.

Thanks, so assuming the same fan this thread identifies and a 2L flask how big of a stir bar?

 

[mjap52]

Thanks, so assuming the same fan this thread identifies and a 2L flask how big of a stir bar?

I use a 1 inch stir bar with good results.

 

[ilikeguns]

1 gallon growler $5
USB Fan $19 ( i got the 12 )
$4 stir bar
salvaged hard drive magnet

For under $30, you can get a stirplate that can make 3L starters.. awesome find!

 

[HDIr0n]

They do make stir Bars for convex bottoms. Look up barbell stir bar, they aren't as cheap but they aren't horrible if you are doing a large starter and don't have a 5L+ flask. Brewmasters Warehouse did have them, they might get them in sometime soon.

 

[theCougfan97]

Sorry if I repeat a question but why does my stir bar keep getting tossed off center? At lower speeds I can get it to stay but with no whirlpool action. I can see at low speeds its spinning just a little off center almost doing tiny circles while also spinning. My assumption it the the magnet is a hair off center but its a HD magnet so it's a funky shape. Any ideas?
(2L flask, 2 laptop hard drive magnets stacked, 1"stir bar, thread specified fan)

 

[fc36]

Sorry if I repeat a question but why does my stir bar keep getting tossed off center? At lower speeds I can get it to stay but with no whirlpool action. I can see at low speeds its spinning just a little off center almost doing tiny circles while also spinning. My assumption it the the magnet is a hair off center but its a HD magnet so it's a funky shape. Any ideas?
(2L flask, 2 laptop hard drive magnets stacked, 1"stir bar, thread specified fan)

One thing that helps is having a bigger stirbar. The 1" won't cut it to make a full 2L flask even show a ripple, much less a full vortex. Another thing to check out are stirbars with the ridge in the center that acts as a fulcrum for it to spin on. And lastly, when dealing with funky shaped HD magnets (I have them and so do many many many of the other homebrewers out there) what I found worked super well was to literally just sit there with your stirplate cover off and spin your fan and adjust the magnets over and over until you find a sweetspot where you see very little wiggle or wobble. Then rather than drawing an outline and then applying glue to the back side and possibly losing the exact position, just mix up a mini batch of JB Weld and goop it all around the magnet edges to lock them in place at that aforementioned sweetspot.

 

[theCougfan97]

just sit there with your stirplate cover off and spin your fan and adjust the magnets over and over until you find a sweetspot where you see very little wiggle or wobble.

How do you do that? If I am just using the magnet and fan I can't identify the center point because of the shape. I tried with the stir bar on the magnet but there is a little play in where the stir bar will stick so that doesn't seem reliable enough.

 

[ilikeguns]

i'm using a 1" stirbar with the hard drive magnet, the model 12 fan an am able to get a "slight" vortex in a 1 gallon growler.. minimum of 1" in the starter.. 3-4" in water. It did take a little positioning of the magnets to optimize it.

 

[fc36]

How do you do that? If I am just using the magnet and fan I can't identify the center point because of the shape. I tried with the stir bar on the magnet but there is a little play in where the stir bar will stick so that doesn't seem reliable enough.

Real easy. Put the fan on a table surface and turn it on. If it skitters and moves itself across the table surface, the magnets are off center and need to be adjusted. Just keep moving them little by little until you find a sweetspot (centerpoint). It'll take you a couple of tries, but once you feel comfortable mix up that JB Weld and lock them in place. Believe me, if the magnets are close to being centered, the stirbar will fall inline and not misbehave (as much )

 

[cbzdel]

Just wanted to pass it along, it may have been mentioned already though. I got this fan from NewEgg for $14.99 shipped, I didnt need anything else off Amazon so I did not qualify for the shipping, plus they are based out of my state so I have to pay sales tax with them as well.

 

[theCougfan97]

Real easy. Put the fan on a table surface and turn it on. If it skitters and moves itself across the table surface, the magnets are off center and need to be adjusted. Just keep moving them little by little until you find a sweetspot (centerpoint). It'll take you a couple of tries, but once you feel comfortable mix up that JB Weld and lock them in place. Believe me, if the magnets are close to being centered, the stirbar will fall inline and not misbehave (as much )

My fan does budge but my stir bar still gets tossed. Does that mean I need a bigger stir bar?

 

[fc36]

My fan does budge but my stir bar still gets tossed. Does that mean I need a bigger stir bar?

Does budge or doesn't budge? Because if it does budge that means the magnets are off center and the small 1" stirbar will get thrown all the time. I have a stirplate that is rock solid centered and I can get a ripple in my 2L flask even with the 1" stirbar, but I use a 2" stirbar for big starters and the 1" is for starters 750mLs and under.

 

[theCougfan97]

Does budge or doesn't budge? Because if it does budge that means the magnets are off center and the small 1" stirbar will get thrown all the time. I have a stirplate that is rock solid centered and I can get a ripple in my 2L flask even with the 1" stirbar, but I use a 2" stirbar for big starters and the 1" is for starters 750mLs and under.

Sorry does not budge.

 

[SharonaZamboni]

Sorry does not budge.

I had to put a little more distance between the stir bar and the magnets. Right now, it's a Post It notepad

 

[theCougfan97]

Do I want the cyclone of water to touch my stir bar and send up all those bubbles? I can get it to do the cyclone but as soon a it touches the stir bar it gets tossed. Do I just need a bigger magnet?

 

[fc36]

Do I want the cyclone of water to touch my stir bar and send up all those bubbles? I can get it to do the cyclone but as soon a it touches the stir bar it gets tossed. Do I just need a bigger magnet?

No, the cyclone is an area of turbulence. I would fully expect that your stirbar would get tossed once the cyclone touches it regardless of the size of either the stirbar or the magnets. Reduce your speed. Also once you actually start doing starters in there, your cyclone will be less pronounced due to the higher viscosity and density of a sugar/water/yeast solution. In this case, there is a measurable quantity that tells you it's a denser liquid that brewers are directly interested in: Gravity is a measure of density.

 

[kombat]

I built my own stir plate, it didn't work. The first power supply I used wasn't powerful enough to spin the fan when the stir bar was present. On my second attempt, the stir bar would get tossed off immediately. I just gave up and bought a ready-made one from stirstarters.com (not spamming, check my post count - just giving a personal account). It's worked great for my 1" stir bar and 2L flask. I haven't yet tried it with my 2" stir bar and 5L flask, but that'll get to be tested when I finally make my Doppelbock later this summer.

 

[tabrazinski]

We made one using the fan and a couple rare earth magnets. We glued the washer to the fan and never even had to glue the magnets down. Initially we did it for placement, but it worked so well we never messed with it. Then we mounted it into a little project box. Couldn't be happier with it!

 

[Wus67]

Just finished mine up. Total cost less than $5.00, as the only part I couldn't find in my junk collection was a rheostat. It seems to work quite well, but I'm not sure if I'll have to put a different rheostat in, it seems to spin pretty fast even on the lowest setting. I do have a pretty nice vortex going, I'm just not sure how fast it should be going. Other than that it was a pretty fun build, and much easier than I would've expected. So glad I didn't pay $100 to buy one.

 

[ExtremeWade]

I saw this exact fan on Amazon as you have posted. I also viewed the 120mm fan. I have a 2L flask coming my way and was wondering if maybe the bigger fan would be more wide and stronger for the larger flask? No worries if you cant provide a definite answer. Clean build my friend. This post is a life saver.

/w

 

[Pomylka22]

I saw this exact fan on Amazon as you have posted. I also viewed the 120mm fan. I have a 2L flask coming my way and was wondering if maybe the bigger fan would be more wide and stronger for the larger flask? No worries if you cant provide a definite answer. Clean build my friend. This post is a life saver.

/w

I remember seeing someone saying they bought a larger fan but ended up getting a smaller one due to the rpm. Someone correct me if I'm wrong but a larger fan doesn't necessarily mean better performance. It's possible to create more drag and therefore lower rpm and less desirable results. Just my $.02

 

[alien]

It's probably the power (amps * voltage) that best determines the performance, not the rpm or the diameter.

 

[ExtremeWade]

I already went ahead and bought the smaller one. I saw the discussions on the higher RPM. thanks for the replies gents.

 

[Chavi]

Thanks to everyone for the awesome suggestions with this build. Here is mine! I used the smaller fan and used this magnet (since I don't have any spare hdd's).

 

[hogwash]

subscribing for future reference

 

[vNmd]

Thanks to everyone for the awesome suggestions with this build. Here is mine! I used the smaller fan and used this magnet (since I don't have any spare hdd's).

Nice setup. I love Ashton's and have plenty of boxes sitting around. I carved into the side for the switch. Didn't think of going through the top. I can only open the box so far because of the wire to the switch. Going through the top would probably be better.

Love this thread.

 

[Chavi]

Nice setup. I love Ashton's and have plenty of boxes sitting around. I carved into the side for the switch. Didn't think of going through the top. I can only open the box so far because of the wire to the switch. Going through the top would probably be better.

Love this thread.

That looks awesome! Did you use a hdd magnet or another type?

 

[vNmd]

I used a HDD magnet (I have many being in IT). One thing is that new newer larger capacity drives have a larger, stronger magnet than the older drives. I think I might have been too close to the top because of the very strong magnet. Here is a pic of a newer versus older hard drive magnet to show the size difference:

The OP mentioned the front and back guards of the fan are a little different height. My first run was using the closer of the two guards. It ran ok with the real starter, but playing around I noticed it didn't spin when the magnet had a hold of it. I thought it was rubbing. I swapped out the guards for the one that is a little farther away. I have a brew coming in a couple of weeks and will try it out. Again, fantastic thread. I probably would have bitten the bullet and bought a professional one. This was cheap and a nice little project for tinkering around with. If I had a hat - it would be off to the people coming up with these ideas. Don't know how they do it! I am impressed with myself for being able to follow someone else's ideas.