My LHBS gives away free cigar boxes. They look nice and you can find them for a couple of bucks on ebay. A hole saw would work very well on them as well.
My Stirplate... Cheap and Easy Build...
- Thread starter Anthony_Lopez
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I just built mine yesterday. Slight problem, though. Everything works fine, fan spins, rheostat regulates the speed, power switch works... but my fan isn't spinning fast enough. I am using a 5V 310mA Power Supply. What Amperage are you guys using. The voltage shouldn't play a part in the amount of power that is going to the fan, that is determined by the amperage. I just found a a 5V 700mA PS so I'll solder that tomorrow and test it out.
The problem this is causing (and maybe I'll film it and post it tomorrow) is the fan either refuses to spin under the weight(?) of the magnet, without even putting the washer on. Give the fan a little flick and it will start up, but too weak. The other problem I have is, under the best situation I got, the stir bar would start spinning perfectly (this was rare) start creating a vortex (in about an inch of water in a 250ml flask) and as I increased the speed and it started getting about halfway to the bottom of the flask, the stir bar would be thrown. Does this mean the magnet isn't strong enough, in addition to my fan not putting out enough power?
I'm going to try and recreate these results and film it. Expect a video either later tonight or tomorrow afternoon.
The problem this is causing (and maybe I'll film it and post it tomorrow) is the fan either refuses to spin under the weight(?) of the magnet, without even putting the washer on. Give the fan a little flick and it will start up, but too weak. The other problem I have is, under the best situation I got, the stir bar would start spinning perfectly (this was rare) start creating a vortex (in about an inch of water in a 250ml flask) and as I increased the speed and it started getting about halfway to the bottom of the flask, the stir bar would be thrown. Does this mean the magnet isn't strong enough, in addition to my fan not putting out enough power?
I'm going to try and recreate these results and film it. Expect a video either later tonight or tomorrow afternoon.
I had a similar issue with the ps not spinning the fan fast enough with my first assembly. I did end up using a more powerful ps and it now spins the bar just fine. I also had issues with my bar being thrown. I ended up using a washer that I have centered and on it is the magnet as centered as possible. The bar hasn't been thrown once ever since. My guess is you need a higher amperage ps and the mag needs to be centered more.
Found a 12v 900mA PS late last night. I hooked that up this morning and there is definitely more power now. I can get a nice 2L vortex, but it only reaches about halfway down the flask, is this a problem?
Another problem I'm having is adding the washer. I'm having a real hard time centering it. I've been testing it all out with duct tape first, before I glue anything down, and no matter how much I think I've centered it and the magnet, I get wobbles when I switch the fan on. I'm actually having better luck with just the magnet, and no washer, only problem is the short vortex as stated above.
3rd problem is that when the flask is on the stir plate, running, the fan runs slower than when I lift the flask off of it. Once I lift it off you can hear it speed up considerably. I assume this is because the fan is pushing a stir bar through 2L of water, and since it's still creating a decent sized vortex I wasn't too concerned.
My last problem is really just flask design. I have Pyrex flasks and they have a little bulge at the bottom of the flask. This causes the stir bar to be awfully noisey. Anyone else have this happen, and find a solution, or should I just learn to ignore the noise.
Thanks.
In the case of the washer it may be more than it just being centered. Glue'ing a washer to the fan creates more weight at the top of the fan and depending on the fan's tolerances this can throw it off quite a bit on some fans. My previous fan worked fantastically and ended up so well balanced you couldn't even feel a vibration or hear a sound. My most recent model on the other hand... The fan seems cheaper and it was literally impossible to balance almost as if the balance point fluctuates a little bit when it was running to start with and adding the weight just exacerbates the situation. I finally just decided to live with a little vibration (I can get dozens upon dozens of replacements for free if it came to it) from it and go with it and it's been running just fine for months.
Personally if it were me I'd get it as close to smooth as you can and go with it. Unless you're using a big fancy fan with bells, whistles, and lights they're insanely cheap if you have to replace anyway.Alternatively I've toyed with the idea of mounting it to one of those little cheap AC fans you see at WM on closeout after summer for like $3 and putting a voltage divider in the circuit to adjust the speed. They're a lot better balanced and you can remove the steel fan and adjust the washer with a screw and two washers on the shaft to boot. Plus no wall wart = WIN~
Personally if it were me I'd get it as close to smooth as you can and go with it. Unless you're using a big fancy fan with bells, whistles, and lights they're insanely cheap if you have to replace anyway.Alternatively I've toyed with the idea of mounting it to one of those little cheap AC fans you see at WM on closeout after summer for like $3 and putting a voltage divider in the circuit to adjust the speed. They're a lot better balanced and you can remove the steel fan and adjust the washer with a screw and two washers on the shaft to boot. Plus no wall wart = WIN~
Found a 12v 900mA PS late last night. I hooked that up this morning and there is definitely more power now. I can get a nice 2L vortex, but it only reaches about halfway down the flask, is this a problem?
My last problem is really just flask design. I have Pyrex flasks and they have a little bulge at the bottom of the flask. This causes the stir bar to be awfully noisey. Anyone else have this happen, and find a solution, or should I just learn to ignore the noise.
Thanks.
That size vortex is just fine and if the bar isn't getting thrown, I'd deal with the noise.
camiller
Well-Known Member
Apply power to the fan, touch the tip of a red sharpie near the center of the fan hub while it is spinning. Line the hole in the washer up on that small red circle/dot.
edit: Oh, if the fan wobbles on it's axis anyway, might need to get a better quality fan.
It would take an incredibly unbalanced fan to knock over your starter and I would think the agitation won't really hurt anything and could possibly help on some small level so long as you're not throwing your stir bar. Mine's slightly off balance because of the fan and I can easily pull a solid vortex down to the bottom of a 1 gallon Kool-Aid/Tea pitcher. I can do the same with a 1/2 gallon jar with up to a 3/8" thickness bottom. Imbalance isn't the end of the world really as the spiral for your stir bar will be pretty steady either way. Just mount it well. I used an old computer speaker enclosure for a rock solid surface to boot. 
theveganbrewer
Well-Known Member
Where are you getting the flask and bar locally? I was just going to get mine online cause I figured no one had the things here.
Brickout
Well-Known Member
So how'd this work out for you? Was the fan big enough?
I would bet on the latter if it doesn't turn at all. A friend of mine made a small unit (40mm fan) for a tiny stir bar (1/2") and it worked fine.
I made this stir plate today. It worked great!
This is a great tutorial as I have ZERO electrical experience and I got it to work. I used the rocker switch 275-0712 (as I could not find the 275-018). It was labeled Ground, Load , Power (rather than Earth, Load, Supply). Also the sentence "Connect these two wires to the Earth male connector on your power supply." I discovered meant "power switch". After those mental translations, It was running perfectly.
Cheers!
This is a great tutorial as I have ZERO electrical experience and I got it to work. I used the rocker switch 275-0712 (as I could not find the 275-018). It was labeled Ground, Load , Power (rather than Earth, Load, Supply). Also the sentence "Connect these two wires to the Earth male connector on your power supply." I discovered meant "power switch". After those mental translations, It was running perfectly.
Cheers!
Nierika
Well-Known Member
I'm in the same boat as you. I found that a 1/2" bit works for the rocker switch and a 3/8" bit works for the potentiometer. If your not sure if a particular bit will work, just try some practice holes in the plastic bottom that came with the enclosure.
theveganbrewer
Well-Known Member
Thanks to the OP and all the other posts, I've got a 2L starter going now for my weekend brew. I spent $4.89 on the supplies and basically just used a bunch of junk I had lying around at home.
Purchased some N-42 Neodymium magnets from Ebay and used 4 for the big stirplate and will use 2 for a smaller one. Used the other 4 to secure my drip tray to my keezer.
I picked up a free CPU fan from Newegg (they almost always have a free after rebate fan deal going) and used an old 9V power charger I had. First used double-sided tape on a 1-1/2 inch SS washer attached to the CPU fan to center. Then attached the stir bar to the magnets and that mass to the SS washer. I nipped the end of a toothpick and centered it on the fan while spinning and epoxied it briefly while I lathered up the SS washer.
To make the case I just used the top of an old CD-DVD-R spindle case, cut the indented center hole out of the top, stuck it over the top of the fan and laid the flask on the CD spindle cover.
Got a huge vortex with a 1" stirbar in 2L. I did drop the bar a few times when only using 2 magnets, the 4 keeps it going in larger wort volumes. I find 2 magnets, one on each side, works with a 500ml starter.
No electical work other than cutting off the connector to the power supply and connecting it with the CPU power lines. No rocker, no switch. Plug it in and it goes, take it out of the socket and it stops.
Purchased some N-42 Neodymium magnets from Ebay and used 4 for the big stirplate and will use 2 for a smaller one. Used the other 4 to secure my drip tray to my keezer.
I picked up a free CPU fan from Newegg (they almost always have a free after rebate fan deal going) and used an old 9V power charger I had. First used double-sided tape on a 1-1/2 inch SS washer attached to the CPU fan to center. Then attached the stir bar to the magnets and that mass to the SS washer. I nipped the end of a toothpick and centered it on the fan while spinning and epoxied it briefly while I lathered up the SS washer.
To make the case I just used the top of an old CD-DVD-R spindle case, cut the indented center hole out of the top, stuck it over the top of the fan and laid the flask on the CD spindle cover.
Got a huge vortex with a 1" stirbar in 2L. I did drop the bar a few times when only using 2 magnets, the 4 keeps it going in larger wort volumes. I find 2 magnets, one on each side, works with a 500ml starter.
No electical work other than cutting off the connector to the power supply and connecting it with the CPU power lines. No rocker, no switch. Plug it in and it goes, take it out of the socket and it stops.
HenryVance3
Well-Known Member
Well done sir!
theveganbrewer
Well-Known Member
I bought 10 Pc N42 1/2"x1/8" Strong NdFeB Neodymium Disk Magnets off ebay from CMS and used 4 to get a 1 inch stir bar going in a 2L flask. 2 magnets total worked on a 1L flask (one magnet per side). Good size magnets for other projects too.
twd000
Well-Known Member
I got a brand-new 12 Volt DC brushless fan from Radio Shack.
http://www.radioshack.com/product/index.jsp?productId=2102823
I had it working for a few minutes, off a 12 VDC/500mA wall wart. Later in the course of hooking up the rest of my control circuit, I noticed that the fan no longer spins when voltage is applied. It "locks up" the rotor and won't free spin until you remove voltage. Is it possible to fry one of these things by applying voltage in reverse or something?
I have tried powering it directly with the 12 V supply, and a 4.5 V supply, and it just locks up and won't spin until I remove voltage.
http://www.radioshack.com/product/index.jsp?productId=2102823
I had it working for a few minutes, off a 12 VDC/500mA wall wart. Later in the course of hooking up the rest of my control circuit, I noticed that the fan no longer spins when voltage is applied. It "locks up" the rotor and won't free spin until you remove voltage. Is it possible to fry one of these things by applying voltage in reverse or something?
I have tried powering it directly with the 12 V supply, and a 4.5 V supply, and it just locks up and won't spin until I remove voltage.
twd000 said:
In don't know the answer, but I went through 4 fans and several power supplies before I found a working combo.
In have since moved on to using a USB fan with speed control included
-=Jason=-
Sent from my HTC Incredible using Home Brew Talk
twd000
Well-Known Member
Well I don;t have the wires soldered - I'm just twisting them together. So I have tried both ways. One way nothing happens, the other way the fan "jumps" then locks up. There no way for a short in the external wiring - just a single red and black wire, and they're not touching each other. I'm wondering if there is a transistor or diode internally that I fried, that could cause a short?
It doesn't beep on the continuity check on my multimeter. I get 135 ohms, from red to black across the fan leads?
Flomaster said:
WTF?
Do you even look at the power ratings of the fans and the powerful supplies? If you provide a decent voltage, and the adapter is able to meet the fan's minimum amperage requirements (both operating AND startup), there's no reason it shouldn't work, unless you have defective components.
Assuming they're not defective, there really shouldn't be any guessing or trial-and-error involved in finding two components that work together. None whatsoever.
twd000
Well-Known Member
The plug says 500 mA @ 12 VDC, and the fan lists a max of 0.32 A (320 mA) so it should be more than enough, no?
twd000
Well-Known Member
But I ought to be able to spin it w/ my finger to get it started, right? It;s the opposite; like the magnets are locked in position preventing it from spinning
twd000
Well-Known Member
yeah it's this one
4" Cooling Fan : Computer Fans | RadioShack.com
bought it new, and like I said I had it work a couple times but now it won't spin up
If you have your neo mags on it that can hose you. Try without the mags. If it works remount with more shielding (aka more washers, they can be sandwich glued together).
Honestly, I have no experience with RS fans. But for around that price, you could have gotten a killer, high-quality, premium name-brand fan (from the right stores, of course).
Does it just have the black and red wires?
Does it just have the black and red wires?
twd000
Well-Known Member
no magnets on it yet. Literally just touching the bare red and black leads to the exposed leads from the power supply
I had a box of old computer gear I had retired and some extra wall worts lying around. from 6v, 9v, 12v. seems all fans would start to spin, or jerk a little but never spin. I tried several combinations using the parts I had on hand only to find out non would work. so yes it's possible I had bad fan, and or power supplies. I wasn't about to buy new gear so I opted for the USB fan and speed controller route for $8.99
-=Jason=-
Alternatively if it works when you plug it up to your cpu normally you might consider swapping the polarity of your wall wart. Alternatively if you have a meter (any cheap one works) you can check the voltage. Make sure it's dc out. I've seen some with bum components that out ac even tho rated for dc. If the rectifier/diode blows it's usually an open but if shorted it might seem to work but really not.
twd000
Well-Known Member
I can't (easily) plug it into my CPU to test - it came right out of the box with bare leads, no Molex connector. Multimeter tells me I have 15 Volts DC coming out of the wall wart. So a DC brushless fan does have a rectifier/diode that can blow? I am reading 135 k-ohm across the fan leads - not open circuit.
Not usually on the fan but I have seen several that would not work unless the correct combination of +/- were used. The wall wart does have diodes though most likely. They are generally step down transformers with 1/2 - 4 diodes set to filter/clip the AC. If you've got 15V DC coming form the wart I see no reason why it wouldn't turn it. Switch the polarity is the best suggestion I could make at this point. There is a very VERY slim chance it could be issue with the transformer coil which you can quickly discount by plugging a 9V battery up to the fan if you have one. I'm assuming it's a 12V fan and not a 5V one correct?
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