My homebrew stirplate

I wanted to do more pics as I was going along but I didn't really think any emphasis was on the circuit. It seems that most talk was about magnets and stirbars. I also don't teach electronics very well. But here is what I have.

For what it's worth to anyone struggling with a "spun-out" stirbar- A huge breakthrough for me was to get the magnet closer to the bottom of the flask. I am using one magnet from a hard drive, velcro'd on the center of the fan hub (for easy adjustment). My stir plate is constructed with 1/8" hardboard, including the top. This originally put the magnet a total of about 1/4" away from the stir bar itself. I ended up cutting a 4" square hole (same size as fan) in the top of the stir plate and jacked up the PC fan as close as possible to the flask bottom without the magnet hitting the flask. Viola!! For me, this solved two big problems:
1) it provides much greater magnetic strength to hold the stir bar in place
2) because of the greater magnetic force, it minimizes the fan speed down to a reasonable level

Adjustment of the magnet on the fan hub to get the bar to spin in a perfect circle is pretty crucial too, especially when you crank up the speed.

I am now able to spin a 2" stir bar in 2L without issues, not to mention a good vortex!

Cheers!

Would you have any intrest in making a stirplate for me if I paid for the parts and your time and effort? I would attempt to put this together myself but my eyesight is not very good so I am not sure of how well it would turn out. I wont need it until sometime after the 1st of the year.

Let me know.

Building things for others is really not my gig, but there are others on this forum that have built stirplates for a fee. I think that Yuri dude builds them for folks. Check the threads. Good luck!

ChrisS said:

Would you have any intrest in making a stirplate for me if I paid for the parts and your time and effort? I would attempt to put this together myself but my eyesight is not very good so I am not sure of how well it would turn out. I wont need it until sometime after the 1st of the year.

Let me know.

Click to expand...

Contact Yuri,
He may have some already made and ready to ship.... A top notch product so I read.

Need a little help - no need stating that even though i can build stuff i have close to no idea about electronics.

2 questions....

1. Guy at electronics store was out of ceramic capacitros, and gave me a plastic one instead. Will this work, and does this capacitor have no polarity ?

2. What is in, adj and out on the LM317




Cheers
Jakob

Plastic film caps have no polarity.

On the VReg, datasheet from ST can be found here: http://www.st.com/stonline/products/literature/ds/2154.pdf
Basically, left to right on your pic would be Adj, VOut, VIn.

I did it !!!!

Who would have thought i could actually put together an electric circuit. Now all i need to do is get and mount some magnets, and i am stirring !

Thx salty, and scimmia for the data !

Cheers
Jakob

MrSaLTy said:

This circuit can vary the voltage from about 1.3V to just under 12v I recommend this if you have a little electonics knowledge and know how to solder. Here is an EXCELLENT tutorial on how to build this circuit with component placement and everything. I have a list of parts etc at the end of this post.

http://casemods.pointofnoreturn.org/vregtut/tutorial-full.html

Click to expand...

This doesn't seem to work when I click on the link. Does anyone have another link for it or something very simular?

nduetime said:

This doesn't seem to work when I click on the link. Does anyone have another link for it or something very simular?

Click to expand...

Their homepage says "Scooping up the ashes from a power surge; please stand by." so I'm assuming it'll be back soon.

pbowler said:

Sorry to interrupt, but this may be helpful.
variable speed Case Fan
http://www.newegg.com/Product/Product.asp?Item=N82E16835220013
looks like 90% of the work is done already
$17

Click to expand...

Price is down to $12.29 each with FREE shipping. Pulled the trigger on two of them - the other is for my already- SilverStone brand PC case!

Now I just need a box, magnets, and stir bar. Have the power supply somewhere in a box at home.

MrSaLTy said:

This circuit can vary the voltage from about 1.3V to just under 12v I recommend this if you have a little electonics knowledge and know how to solder. Here is an EXCELLENT tutorial on how to build this circuit with component placement and everything. I have a list of parts etc at the end of this post.

http://casemods.pointofnoreturn.org/vregtut/tutorial-full.html

Click to expand...

Okay...so I couldn't wait and I went out to my local Radio Shack and purchased all the stuff for lots of money. Now I want to start but the link doesn't work. Each time I click on it it tells me the server can't be found. I type in pointofnoreturn.org but I get the ash message as previously stated. So here I am with parts on hand and wanting to start this as my first project in soldering/small electronic components. Mrsalty, do you happen to have the information (component placement, etc.) saved anywhere else that I might be able to access or that you could email me? I know there is a photo and schematics, but like I said this is my first attempt at something like this and I don't want to ruin all those pretty, little, expensive parts that Radio Shack overcharged for. Please!!!???!!!

nduetime said:

Okay...so I couldn't wait and I went out to my local Radio Shack and purchased all the stuff for lots of money. Now I want to start but the link doesn't work. Each time I click on it it tells me the server can't be found. I type in pointofnoreturn.org but I get the ash message as previously stated. So here I am with parts on hand and wanting to start this as my first project in soldering/small electronic components. Mrsalty, do you happen to have the information (component placement, etc.) saved anywhere else that I might be able to access or that you could email me? I know there is a photo and schematics, but like I said this is my first attempt at something like this and I don't want to ruin all those pretty, little, expensive parts that Radio Shack overcharged for. Please!!!???!!!

Click to expand...

All the diagrams you need are already in this thread. See post 1 and post 22. There's not much more to it - I'm completely incompetent with electronic parts, and I can still kind of get what MrSalty has drawn out.

chriso said:

All the diagrams you need are already in this thread. See post 1 and post 22. There's not much more to it - I'm completely incompetent with electronic parts, and I can still kind of get what MrSalty has drawn out.

Click to expand...

Of course I have found the important information throughout the post regarding the schematic and even the picture to show what it looks like. However, I'm more curious about the underside of what the board looks like, so I can make sure I'm doing it correctly.
Because this is my first project, I have no other experience, I've consulted the web to hopefully find answers to my question. Since the board suggest in the parts is a general purpose pc board, I'm left wondering what the underside (copperside) of the board looks like either half way done or when completely finished.
I would assume these boards are also called Stripboards right? However, based on the photos I've seen of stipboards, there should be solid strips of copper that run the width of the board. However, the pc board listed for this project does not have these. Only each hole is surrounded with copper.
I know it is not PCB (printed circuit board) which means there are no guide lines to help make sure things are in the right spot which is pretty important according to http://www.kpsec.freeuk.com/stripbd.htm Appearantly, vertical placement errors can cause problems on stripboards. I'm trying to aviod those.
Also, that same site states that components can be connected to one another by use of uninsulated wire. Since no pictures of the underside (copperside) of the board were supplied, I wondering if that was how this poject was done.
As easy as this project is and sounds, I have questions. Does it mean that I shouldn't attempt it, no! I'm trying to learn and am only asking for some help along the way.

nduetime said:

Of course I have found the important information throughout the post regarding the schematic and even the picture to show what it looks like. However, I'm more curious about the underside of what the board looks like, so I can make sure I'm doing it correctly.
Because this is my first project, I have no other experience, I've consulted the web to hopefully find answers to my question. Since the board suggest in the parts is a general purpose pc board, I'm left wondering what the underside (copperside) of the board looks like either half way done or when completely finished.
I would assume these boards are also called Stripboards right? However, based on the photos I've seen of stipboards, there should be solid strips of copper that run the width of the board. However, the pc board listed for this project does not have these. Only each hole is surrounded with copper.
I know it is not PCB (printed circuit board) which means there are no guide lines to help make sure things are in the right spot which is pretty important according to http://www.kpsec.freeuk.com/stripbd.htm Appearantly, vertical placement errors can cause problems on stripboards. I'm trying to aviod those.
Also, that same site states that components can be connected to one another by use of uninsulated wire. Since no pictures of the underside (copperside) of the board were supplied, I wondering if that was how this poject was done.
As easy as this project is and sounds, I have questions. Does it mean that I shouldn't attempt it, no! I'm trying to learn and am only asking for some help along the way.

Click to expand...

AHA - sorry. I misunderstood your question. My apologies.

chriso said:

AHA - sorry. I misunderstood your question. My apologies.

Click to expand...

Do my questions make any sense? I know I have a tendency to ramble on and talk too much. Sorry about that.

It appears there are wires from holes to holes but it's hard to make out with all of the wires hovering above and around in the closeup picture.

nduetime said:

Do my questions make any sense? I know I have a tendency to ramble on and talk too much. Sorry about that.

It appears there are wires from holes to holes but it's hard to make out with all of the wires hovering above and around in the closeup picture.

Click to expand...

Your questions make sense, I just read your OP wrong. I think they are soldered with thin wire between each terminal. I can't tell for sure, either. Sorry I don't have more info on this. Hoping either Yuri or MrSalty will jump in....

Here's another good article - but again with no bottom shot! http://brewiki.org/StirPlate

I've got my stirplate mostly together, but I'm running into a couple of minor issues.

Parts used are:


1) Fan spins too fast. I used the pre-assembled Silverstone 120mm fan linked to earlier in this post, which starts at about 800 RPM and goes up from there.

2) Magnet troubles. Using the tiny RadioShack rare earth magnets, it is almost IMPOSSIBLE to glue them on because when you place one magnet, the one next to it either moves away and falls off the fan, or it flips on top of the magnet you're trying to place. Harvested a couple of Hard drive magnets, but I need to seperate them from their brackets still.

3) Broken f'ing power jacks. I've gone through two, I need to go to RadioShack for the fourth time in two days. The first one had the ground post break off, the second one had the ground contact inside of the jack bend in half when I tried to plug in the power cord. Cheap f'ing jacks. Grr. And they're $3.20 each, too. Rrrrrrrr.

So my biggest question is .... to get my rotation speed down to an acceptable range, should I go get 1 more potentiometer (that will be run at about 50%) and add it to the circuit? Should it go between the existing knob and the fan (its own circuit) or between the power connector and the fan?

Finally, does it matter what kind of potentiometer I get, in terms of resistance? What's the "right" number?

I need to leave for R.S. pretty soon but I will wait as long as I can if anyone knows the solution to my quandrary. Otherwise, I might just buy 3 or 4 different pots and see which winds up best. Not preferable, but it would work.

Thanks y'all!
Chriso

You may be able use a lower dc input voltage with that fan to slow it down. Depends on the guts. Could be a cheap and quick solution.

Found another wall wort in my pile of cables. This one is 7.5V, 1000mA. I'm a bit worried about the amperage. Oh well. This one is closer. It spins 3 or 4 times then loses it.

Two things I forgot to mention in the last post - The stirbar is the type with a ring down the center. I thought I read someone else saying that that gave them grief, but I can't recall. The other thing is that the bottom of the 1000ml Pyrex flask is indeed slightly concave.

I should've just bought one from Yuri. Rrrrrrr. I don't do well with small things.

Edit: Also, I'm down to only one hard drive magnet. I broke the other trying to get it off of its mount. Today has not been so good for this project. I'm tired of breaking something new every time I fix the last problem I caused. >_>

Having some problems with mine... I built the LM317 voltage regulator no problem. I used two magnets from one hard drive, but my stirbar wont center itself. The magnets are glued centered and as far apart from eachother as possible.

My 2 inch stirbar seems to work best in the 2000mL flask, but it rides funny. How come it wont center itself? Because of this, I can get it spinning, but nowhere near as fast as needed to pull a cyclone.

Should I not have the magnets glued on opposite ( one N up, and one S up)?

Thanks

*edit... attempting this method

http://www.brewboard.com/index.php?showtopic=80139

just waiting for epoxy to dry. I'll report back soon.

One magnet should be strong enough... I believe the magnets from hard drives have a pos / neg at each end of the mag. So with TWO mags your stir bar may not know which mag to center on. Try one mag and get back to us.

I tried it as shown in the link I posted above, two magnets glued together, then centered on the fan.

Working great!!!!!!!!! :rockin:

My 1" stirbar seems to work best, I can go right up to full speed with it. The 2" and the 1-5/8 both get tossed.

Excellent device! Cant wait to use it!

I'm on only 1 magnet right now and I think I can't get my fan rpm low enough. If I hold the glass directly over the magnet, it kinda sorta works. But only if I brush against the fan to slow it down.

chriso said:

I'm on only 1 magnet right now and I think I can't get my fan rpm low enough. If I hold the glass directly over the magnet, it kinda sorta works. But only if I brush against the fan to slow it down.

Click to expand...

What are you using as a speed controller?

JoeRags said:

What are you using as a speed controller?

Click to expand...

SilverStone inline speed controller, came with the fan. Goes 800RPM - 2400RPM. I'm trying to think of some way to slow it down. But the controller has a seperate circuit than the power does. Both circuits end at the fan.

If you have any electronics experience, I'd recommend building the LM317 speed controller... its very simple, and works great. I had most of the parts lying around, though I had to improvise a bit since I couldnt find a 1k resistor.

is it just me or are the pictures not workn on this post anymore?

kjones said:

is it just me or are the pictures not workn on this post anymore?

Click to expand...

I've noticed that I've had to repost some of my PICs after the site got revamped tis last week or so... look in your gallery... My stuff all had a different address

Anyone try adding an inline fuse? Reason I ask is I am not allowed to burn the house down. I am planning on using a power jack to plug my 12v/500mA power supply into, because I do not want to hardwire the power. Ordering my parts tomorrow...

Absinthe > Coffee Table

I don't think anyone's mentioned it, but I don't see a problem with adding an inline fuse. I would probably be a good idea if the power supply doesn't have any kind of protection in it.

Here's my problem:

I have this really sexy stirplate I made out of a snazzy cigar box.....the works. I can't get the damn bar to stay on the magnets...it flings it off! However, if I put the bar on the box, it works like a champ......any ideas? I've used a 1l flask and a .5 gallon growler....both to no avail

98exl, did you just mirror the original setup, or did you customize at all?

I finally got mine working with the pre-assembled SilverStone fan - I had 2 problems.

1st, I had to add in another potentiometer to get my RPMs to an acceptable range. I used a volume pot out of my broken electric guitar - but I installed those pots myself 3 years ago, they aren't standard sizes or resistances. I thought it was a 25K ohm pot I put in? Anyways, I mounted it inline between the power cord + and the fan. Then the fan controller is on a seperate circuit. I'm sure that makes no sense. But anyways, now I start the stirplate with both knobs at 0, raise one, then the other, then one, then the other. I can get a decent vortex with water, but haven't tried with wort yet. This is a 1 3/8" stirbar by the way.

2nd, my hard drive magnet sucked, so I went to JoAnn fabrics and picked up a pack of 8ct 1" ceramic magnets. Glued 2 on each side of the fan hub, and it worked perfectly. Neither the HDD magnet or the Radio Shack tiny Rare Earth magnets did anything.

did I customize it....of course I did!

I am really thinking it's the magnets....when I ghetto-fied it all up it worked great, but in the box, not so much....

I need to post up my damn pics, it's really sweet looking...but just not working....so JoAnn fabrics huh? I should try that out

I would think Hobby Lobby carriesthem too, but JoAnn's is 20 minutes closer to me. I found them near the "woodworking-type-hobby-supplies" section. At least, as close to woodworking as JoAnn's has. If you're near the paint and wood glue and scrapbooking, you're probably close. The store clerk I asked had no clue if they had magnets or not.

chriso said:

I would think Hobby Lobby carriesthem too, but JoAnn's is 20 minutes closer to me. I found them near the "woodworking-type-hobby-supplies" section. At least, as close to woodworking as JoAnn's has. If you're near the paint and wood glue and scrapbooking, you're probably close. The store clerk I asked had no clue if they had magnets or not.

Click to expand...

chriso > JoAnn's Store Clerk

Another thing to check is that the bottoms of your vessels are flat. If they're not, you're going to have a hard time using them. If it works without the flask, but not with it, the first things I would check would be that and that the magnets are close enough to the bar.

Go up in speed alowly so the liquid have a moment to accelarate, that can remedy throwing of the stirbar.
Also move swift past speeds where the stirbar start to wobble and eventually trow after some seconds, it is very clear from the sound of it when it start to wobble.
Make sure that your container is centred, if you stir off center, that that will throw the magnet too. You can hear when you move the container around where center is, then it will stir almost quiet and make a perfect dimple/vortex depending on speed.
If you have 2 magnets on your fan setup make sure they have different poles op 1N and 1S.
I use 2 magnets with 6-7 pound holding power each, that seem just right for my setup stirring ½ gallon.

Have you tested holding power through your cigar box setup? maybe material/distance takes too much power away ?

This show holding power of the magnets i used, and it also show why distance is important


For the Metrically challenged 4kg=8 pounds and 6 mm= 1/4 inch

And yes, at the distance from magnet to container bottom where the stirbar is so great that holding power is really low, but still it does matter if power 0,10 or 0,15pound per magnet (50 % difference)

Just my $.02

Cheers
jakob

I tore a 120mm fan out of a toasted pc power supply, and ripped out 4 magnets out of a pair of toasted scsi drives from work. I've got some spare plexiglass at home and access to a virtually unlimited supply of 5V wall worts. I have some of those speed control thingys for fans layin around... so i'll use those to dial in the speed. I'm gonna toss one together maybe over the weekend. It should be a fun little project!

****... I got bored waiting for this stir bar to come in so I turned my hard drive into a speaker

http://homebrewtalk.com/showthread.php?p=549799#post549799


[youtube]M21kWLqH77w[/youtube]