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

[BrewersKaramazov]

Thank goodness you posted, I thought I had become the bringer of death.

 

[Grasslands]

I'm about to do this as well. I've got most of the major components: 80mm fan, HD magnet, 10.6v charger plug, cigar box enclosure.

We'll see if my extreme novice approach to all things electrical can result in something positive.

I plan on drilling a few extra holes in the box to exhaust a little heat. This thread has been extremely helpful.

 

[Anthony_Lopez]

Glad to hear! For those of you guys that are doing this build now, I'd love to know which posts aside from my original post have helped you. Perhaps I could consolidate the other information into the original post to make it easier for the newcomers to this thread...

 

[Grasslands]

For what its worth, since my enclosure is a bit shorter in height than the suggested radio shack one, it'd be a combination of your first post and the drawn out diagram post.

I got mine working at its most basic level, though it's not finished yet - my enclosure is a 2" tall (lightweight) wood cigar box. I just need shorter screws, some padding and to drill a few holes and I'm all set.

 

[sils13]

Mine workin great! This thing is awesome!! Lol

 

[fiat84]

Another option is to use only a 5V power supply/USB which reduced the fan speed enough to vortex. Did not work with the full 12V molex computer power supply connection to fan molex(no splicing) as that spun all three 80-120mm fans 1350-2600rpm I tried too fast. Glued a big washer to the fan then put one hard drive magnet on top. A variable voltage power supply would be more versatile. Might still make the nice case variable speed switch version but do not have those parts yet.

Most USB port's are 5V(some newer motherboards optionally output more) so using a USB cable cut off one end then spliced only the red and black wires to a 80mm 2300rpm fan red/black wires and its working fine am getting a small vortex. Will hopefully source someone's 5V cell phone charger to remove the computer power connection. Used an old spare PC to be safe after finding lots of Google hits on modding USB cables to power 5V electronics.

Made a temporary stir bar from a bolt with a nut attached at the end to help balance. Wrapped it in a few layers of 6 mil vapor barrier plastic then melted together with a heat gun. After it cooled added an O-ring to the center as a balance point. Makes a small vortex in water with a curved bottom pickle jar and a flat bottom coffee pot. UPDATE: in a SG=1.044 dark wort did not start swirling in the curved bottom pickle jar but did eventually start swirling in the flat bottom coffee pot. Had to re-start it a few times before it got going and then took over a minute to vortex as the wort is thicker than water. Maybe the balance point was off a bit on the home-made stir bar and never did re-try the curved bottom pickle jar.

Originally posted here added a few updated details: https://www.homebrewtalk.com/f51/show-us-your-diy-stir-plate-228400/index4.html#post2844031

 

[wrench]

I just got my prototype working using parts I had around the house. So my component list is a little different:

• 120V Radio Shack fan
• Rotary ceiling fan speed control
• Kuba Kuba cigar box
• Salvaged appliance power cord
• Two big magnets (not rare-earth)

The only thing I bought was a lighted switch for the bling factor in the finished product. It's a rocker that lights red when the plate has power and goes green when it's on.

Here are some of my initial thoughts:

• The lighted switch looks cool
• The stir bar I have is probably too big (3") and is keeping the speed down.
• The load is producing a lot of heat in the fan motor - too much?
• I'll play with a smaller stir bar, different magnets, and different spacing in the hopes of getting better speed and less heat.
• Might have to add some cooling vents in the box to get that heat down
• The 120V fan is beefy, heavy and all metal which virtually eliminates any vibration you would get with a plastic PC fan.
• The fan control is infinitely-variable (not 3-speed) and also has a trim screw to adjust the low-speed cutoff - very cool.

 

[Catt22]

I just got my prototype working using parts I had around the house. So my component list is a little different:

• 120V Radio Shack fan
• Rotary ceiling fan speed control
• Kuba Kuba cigar box
• Salvaged appliance power cord
• Two big magnets (not rare-earth)

The only thing I bought was a lighted switch for the bling factor in the finished product. It's a rocker that lights red when the plate has power and goes green when it's on.

Here are some of my initial thoughts:

• The lighted switch looks cool
• The stir bar I have is probably too big (3") and is keeping the speed down.
• The load is producing a lot of heat in the fan motor - too much?
• I'll play with a smaller stir bar, different magnets, and different spacing in the hopes of getting better speed and less heat.
• Might have to add some cooling vents in the box to get that heat down
• The 120V fan is beefy, heavy and all metal which virtually eliminates any vibration you would get with a plastic PC fan.
• The fan control is infinitely-variable (not 3-speed) and also has a trim screw to adjust the low-speed cutoff - very cool.

I've built quite a few stir plates using that same Radio Shack AC fan and an ordinary rotary type light dimmer. IME, that fan needs a lot of cooling ventilation. It does not produce a lot of heat, but it can build up if the fan is confined in a box. IOW, it's not the load as much as it is the lack of ventilation. FYI, I've also used fans with plastic housings and there were no problems with vibration. IME, most vibration problems are a result of poorly balanced and aligned magnets on the fan and have nothing to do with the fan motor itself. I use the 2" stir bars with good results. IMO, it's best to match the stir bar to the magnet spacing (if using two magnets, of course). While a 3" bar is large, it should be useable I would think. I use DC fan motors on my current builds for much improved speed control.

 

[Chefencore]

this thread really helped my build. I have yet to try it with an actual flask and stirrer (pyrex and auxiliary magnet I have wrapped in plastic) i used a wood cigar box, HD fan and magnets, phone charger and blank CDs (what are those?) to build up the height. and lots of hot glue. i attached some cabinet liner (the foam-y type) to the bottom and top with double-sided tape to reduce vibration and stop movement of device and flask. I’ll post pics when i get em!!!

I will verify if I need a volume knob once I get my stir bar

 

[BeerMike]

So this is my final product. I really liked this thread. The first post is what helped me the most.

I had an old computer fan that actually came with a potentiometer that turned off also. The fan is SILVERSTONE FM123 120mm Case Fan. I accidentally snapped one of the fins so i just took them all off.

For magnets I used Magcraft NSN0575 3/8-Inch by 1/4-Inch Rare Earth Disc Magnets which are a little stronger (8lbs each).

Then I got lucky for the power supply. I had an old router power adapter at 12V and 0.5 Amps, exactly what the fan used, so I just wired that directly.

The box was also from Radioshack, but I went with the slightly larger one (8x6x3) for the fan and the 2L starters. Then used a grommet for the wire going inside and some rubber feet on the bottom.

I assembled it almost the same as the first post but I have the fan mounted to the larger structure. I didn't want holes in the lids. I used washers inside to help minimize how much the bolts stuck out. And the rubber feet raise it enough to prevent scratching.

In the picture I have it running at near full speed with bubbles flying everywhere , but I doubt I'll need to run at that speed with the starters.

 

[topend]

I got mine put together but it doesn't pull the vortex down to the bottom, only about 2 or 3 inches at full power. Will this create the desired effect for a starter?

 

[Anthony_Lopez]

I got mine put together but it doesn't pull the vortex down to the bottom, only about 2 or 3 inches at full power. Will this create the desired effect for a starter?

Yes. You will get a great starter. The purpose is to keep the yeast aerated and in suspension. A small vortex works great.

 

[topend]

Sweet. Thank you so much for putting together this tutorial.

 

[Chefencore]

So I just got a stir bar, and my stirplate keeps throwing it. I haven't put on a speed control yet, but plan on it. But it throws it as soon as I turn it on. Is there a certain way the magnets should be on the fan, or do I need more? I have 2 HD magnets right now. It's a 50mm stirbar with center ring FYI.

 

[Monster Mash]

So I just got a stir bar, and my stirplate keeps throwing it. I haven't put on a speed control yet, but plan on it. But it throws it as soon as I turn it on. Is there a certain way the magnets should be on the fan, or do I need more? I have 2 HD magnets right now. It's a 50mm stirbar with center ring FYI.

You need a speed control. What size power supply are you using?, you should use a 6v or nothing over 9v.

When placing the magnets you should stick them to the stirbar first to get the polarity and spacing correct.

You should use a non conductive spacer between the magnets and the fan motor so they don't interfere with the magnets in the motor.

 

[ekjohns]

short answers yes the magnets can on on wrong check them as mentioned above

 

[topend]

Also, you might have a problem if the diamater spacing of your magnets is not close to the length of your stir bar. Learned that one the hard way.

 

[Chefencore]

it looks like i got the wrong kind of power switch. Radio shack didn’t have the part listed so i improvised. there are only two connectors on the switch. does anyone know how i should wire this?

 

[Chefencore]

Ok so I got it wired, I just hope it takes me low enough to do the job.

 

[Chefencore]

Think I fried it. Plug is hot and it's not working. Guess I need a smaller voltage plug after all. Darn.

 

[camiller]

Think I fried it. Plug is hot and it's not working. Guess I need a smaller voltage plug after all. Darn.

If it is getting hot there is probably a short in your wiring. Check everything. I didn't bother with a switch, just plug it in when i want it to go and unplug to stop.

Edit: Also, you may have problems with the 2" stir bar using hard drive magnets. Remember, HD magnets do not have the poles on the faces but are instead polarized radially. Most of the successful builds using HD magnets use a 1" stir bar which seems to balance in the magnetic field better. If you must use the 2" bar I'd suggest the small disc magnets that are polarized on their faces. I saw some at walmart in a three pack with the office supplies if that helps.

 

[wegz15]

Ok so mine works great with a flat bottom vessel. I got my flask today and it just throws the bar right away. I have a1 and 2 inch bar. Both throw. I have 4 rare earth magnets two per side. Any suggestions? Adds more magnets?

 

[wegz15]

Ok so mine works great with a flat bottom vessel. I got my flask today and they have a convex bottom so it just throws the bar right away. I have a1 and 2 inch bar. Both throw. I have 4 rare earth magnets two per side. Any suggestions? Adds more magnets?

 

[wegz15]

Ok so mine works great with a flat bottom vessel. I got my flask today and they have a convex bottom so it just throws the bar right away. I have a1 and 2 inch bar. Both throw. I have 4 rare earth magnets two per side. Any suggestions? Add more magnets?

 

[camiller]

Ok so mine works great with a flat bottom vessel. I got my flask today and it just throws the bar right away. I have a1 and 2 inch bar. Both throw. I have 4 rare earth magnets two per side. Any suggestions? Adds more magnets?

Well, if it isn't working with the convex bottom it's likely that the stir bar has become too far from the magnet. You could try raising the fan assembly closer to the top of the case, or adding more magnets.

Edit: didn't see your pic at first. Because of the way the magnets are paired up I surprised it runs stably. With two north polls up at one end and two south pols up at the other I could see the bar getting drawn off center one way or the other. Try putting a stacked pair at either end.

 

[Anthony_Lopez]

I would also suggest stacked pairs at either end. Also, you posted 3 times in 5 minutes with the same question. Could you delete two of them please?

 

[TripleHopped]

Ok so mine works great with a flat bottom vessel. I got my flask today and they have a convex bottom so it just throws the bar right away. I have a1 and 2 inch bar. Both throw. I have 4 rare earth magnets two per side. Any suggestions? Add more magnets?

I like the use of the lid from a container of frozen juice.

 

[ekjohns]

it could also be weak magnets. There are several strengths of magnets, and if the ones you bought didnt come with a n rating they are probably not the strongest. I am planning on buying some super strong n42 neodyniums from online here soon. The place I am looking at is cheap but absolutly RAPE you on shipping. I will probably order a bunch and resell them at a good price on here. Would people be interested in some at say $5 shipped/ pair. These suckers will be very strong and will probably make it near impossible to toss the magnet (each one is smaller than a dime and has a pull force of 13 lbs!)

edit: Also wanted to mention that these will be easier to balance than the hardrive magnets that are cuvered. If i get enough people interested ill place the order. PM me if you want to get in on this

 

[terrapinj]

check eBay as well

i got these for under $5 shipped

http://cgi.ebay.com/10-Neodymium-di...544?pt=LH_DefaultDomain_0&hash=item45fa74c700

 

[ekjohns]

yeah those are the weaker n35s. for the same $5 if people are interested i can get n42s. you wont get as many but wont have to worry about stacking a bunch up or having to get the fan super close to the top of the box