MAG2 problems...

Brandon, you might want to try a trash can mod on the mag 2. :)

Like Jack said, the nature of kalk reactors can run a toll on any pump. But I'm wondering, did you check to see if the impeller is broken free from the magnet? Just wondering how many times your Mag pump has cycled (on/off's per day and how long running).

Have you thought about putting a magnetic stirrer on it? You'd have much fewer problems and it's a lot cheaper than a new mag pump. And really, it can be cheaper than a new impeller even. All you need is a small fan, a couple magnets, a stir bar, and a small stand/whatever to raise the reactor up to place the fan under it.
 
Siffy- Do you have plans you can show for building a stirrer? I actually want one for beer brewing... but the knowledge could come in handy for reef keeping too.
 
Thanks Jack!

Will: I'll check out the mods... thanks for the heads up.

Its turned on for one minute every 3 hours. I could (and maybe should) reduce that.

I had thought about magnetic stirrers before I got it, but I had completely forgotten since then! That would probably be much better than continuously buying MAG2s... :D

I'd love to see any plans you have, too. I'll also scour eBay... I've looked for them on there before and I think there's usually a handful on there at most times.

Thanks for the replies guys!

Brandon
 
<a href=showthread.php?s=&postid=12425078#post12425078 target=_blank>Originally posted</a> by DMBillies
Siffy- Do you have plans you can show for building a stirrer? I actually want one for beer brewing... but the knowledge could come in handy for reef keeping too.

Yeah, I've seen several around and actually most are for brewing.

Gonna try and find a few.
 
Ok, what's better than a build thread/webpage with pics?

Videos of course.

More complicated if you really need variable speed and ... hot chocolate.
http://youtube.com/watch?v=pXsOhEdTcqs

The fun route. :)
http://youtube.com/watch?v=FMTWMvDs5e4

"magnetic stirrer" actually has 30 hits on youtube.

http://www.instructables.com/id/Magnetic-Stirrer/

There's always the prebuilt solution, $128.
http://www.labcraftsmen.com/page3.htm

Now if you don't have a PC fan and an AC/DC transformer already laying around, I'd recommend this fan as it's AC. Group order maybe? I'd be in for one. I'd be in for making the order before the meeting as well if anyone is interested.
http://www.alliedelec.com/Search/Pr...1A-1123HST.GN&R=997-0190&sid=469C06805004E17F

It should work with a regular light dimmer as a speed control.

For stir bars, the most reasonable solution is to buy some non-reactive resin coated ones rather than just plunk a piece of metal into the container. And if there's several interested, buying a bag of them probably wouldn't be too bad cost wise. Stowers could probably recommend the best/cheapest place to order them.

I would already have one up and working, but 2 5g water jugs I had for kalk both just cracked after a week or so of water in them. So I'm having to re-evaluate my solution.
 
Awesome! Thanks Will.

FWIW, there are several nice stir bars (if a stir bar can be nice :D ) on eBay for not too much money. A few auctions with multiples, too.

Someone in the other thread brought up torque on the magnetic stirrers. I think on a bought one it may have enough, but with DIY that could be an issue.

I do have an extra 1 amp 12v supply, though. :D I wonder if you could do like maybe multiple smaller magnets on maybe 2 or 3 computer fans. Seems like that may be more effective than trying one big magnetic stirrer in the kalk.

Hmmmm... maybe another summer project to add to the list. :)

Brandon
 
Hmm, only thing I can say about either is we'd have to try and see if it works. I've read that in another thread too and her issue was solved by raising the stir bar with an acrylic plate so it was never submerged by kalk powder. To be honest it really doesn't make sense the way magnets work with the whole inverse square thing :). Multiple stir bars inside the same mixer would likely be problematic as magnets like to stick to each other if they get close enough. I'm willing to build one or a couple by the meeting (or maybe sooner, if I'm in Nashville before then) and we can try it out on your reactor if you want. I'll make a trip to radio shack tomorrow and see just how cheap I can build this. I've already got fans, transformers, and magnets around here, but no potentiometers and frankly it's easier to buy $10-20 of new stuff than find what I already have.
 
So ultimately I think there'd be around the stir bars getting stuck in kalk. And you're right... we'll just have to try! And I'm definitely up for trying on mine. It is on the rather large size for a kalk reactor (maybe 5" diameter and 24" tall or so), but it should be a good test bed.

I think I may have everything I need as well. I will probably not worry about a pot, though, as I don't need adjustable speed. It may be cool to have one slowly ramp up to speed, but I don't think it would be worth the effort (PICs, transistors, etc... I guess you could possibly do it all discrete, but nah... :) ).

The biggest challenge (for me) is a casing that can hold my 15lb reactor on it... and I don't think it should be metal due to the magnets. Hmmm... Actually, maybe a small Sterlite bin turned upside down without a lid on it and some holes for ventilation may work... Something else to ponder.

I may try to dig all this stuff up tonight.

I hear ya on digging up old stuff. My closet is a MESS. But to it I must go for an old harddrive and fan. :)

Brandon
 
<a href=showthread.php?s=&postid=12430301#post12430301 target=_blank>Originally posted</a> by NeveSSL
So ultimately I think there'd be around the stir bars getting stuck in kalk. And you're right... we'll just have to try! And I'm definitely up for trying on mine. It is on the rather large size for a kalk reactor (maybe 5" diameter and 24" tall or so), but it should be a good test bed.

I think I may have everything I need as well. I will probably not worry about a pot, though, as I don't need adjustable speed. It may be cool to have one slowly ramp up to speed, but I don't think it would be worth the effort (PICs, transistors, etc... I guess you could possibly do it all discrete, but nah... :) ).

The biggest challenge (for me) is a casing that can hold my 15lb reactor on it... and I don't think it should be metal due to the magnets. Hmmm... Actually, maybe a small Sterlite bin turned upside down without a lid on it and some holes for ventilation may work... Something else to ponder.

I may try to dig all this stuff up tonight.

I hear ya on digging up old stuff. My closet is a MESS. But to it I must go for an old harddrive and fan. :)

Brandon

Dude, you always gotta worry about pot. I for one don't care for it, so I picked up a 25 ohm 3 watt Rheostat for 4 bucks and a pack of 5 "button" magnets for $2. The magnets just aren't strong enough I believe. And I got a Rheo because their biggest pot was 1/2 watt iirc. It seemed to work well enough for my needs. I already had the fan moving pretty slowly anyway since I was using an old cel charger with a 6v DC output. It did work (without water, didn't bother to test with), but not reliably enough to call a finished product yet. I think a magnetic stir bar is a must. A paperclip hardly worked at all, but the 3 extra button magnets I had would spin fine if started up slowly. Their biggest problem was they wanted to roll around. I may throw some water in my container just to see. There is no way I'd mess with making a digital controller for this, so that is all you buddy.

I'd already had a thought about the stand. Got any old textbooks that you won't hardly get a dime trying to sell back? Well, the one you hated the most + a hole saw and viola. Plus you can easily adjust the depth/height of the magnets by simply drilling out more pages.

As far as hard drive magnets go... sigh. That didn't work out so well for me today, but I do need a stronger magnet. Out of the 4 hard drives I've destroyed in the past month (2 more today), one pair I can't even find the magnets now, one I tried prying and beating loose from it's epoxied holder until the brittle thing just shattered, one I tried heat from a torch but too much made it lose its magnetivity, one I used a grinder to remove excess and it still lost some but not all of its power due to heat build up, the other from that pair is still intact and very powerful, and the last pair didn't even exist as that drive used a stepping motor to position the heads. I plan to try the one I grinded shortly, but if it doesn't work I do have a one last try effort before just ordering some. I should anyway as I've been wanting to get some epoxy or rubber coated magnets for powerhead holders anyway. Anyway, I do have these to try, what do you think?

IMG_1307.jpg


That's a DVD-R (and no not wallet sized) for size comparison. We just bought a new weed eater Friday because the transmission broke on the old one, but the motor is still good.
 
Cool deal, man.

I think I may just order some magnets and a stir bar since I get paid tonight. Sounds like the harddrive magnet thing may not work out so well. I do have older HDDs, so maybe they'll have a better chance at magnets instead of a step motor. Hopefully those will be my only expense. I may go ahead and buy a 120mm fan, though, as I know where I can get one for pretty cheap. Maybe I'll just use the one I have. I'm pretty sure it would have a bit more torque than an 80mm or 90mm... but probably not by much. I just hate tearing a brand-new 120mm fan apart... heh. I guess I'll get over it, though.

Anyway, yeah, I think those old kappa magnets should work rather well. Let me know what epoxy you use to attach it to the motor. :D

Brandon
 
BTW, what magnets are you ordering? Neodymium seem to be the best bet, but what shape? Are disks fine because of polarity?

Brandon
 
Or even *GASP!* a yardsale blender!

Anyone got an extra blender? :D

I may go by walmart and/or big lots tonight or tomorrow to see what the cheapest blender they have is... hehe.

Now I'm getting excited... :lol:

Brandon
 
<a href=showthread.php?s=&postid=12436490#post12436490 target=_blank>Originally posted</a> by NeveSSL
Cool deal, man.

I think I may just order some magnets and a stir bar since I get paid tonight. Sounds like the harddrive magnet thing may not work out so well. I do have older HDDs, so maybe they'll have a better chance at magnets instead of a step motor. Hopefully those will be my only expense. I may go ahead and buy a 120mm fan, though, as I know where I can get one for pretty cheap. Maybe I'll just use the one I have. I'm pretty sure it would have a bit more torque than an 80mm or 90mm... but probably not by much. I just hate tearing a brand-new 120mm fan apart... heh. I guess I'll get over it, though.

Anyway, yeah, I think those old kappa magnets should work rather well. Let me know what epoxy you use to attach it to the motor. :D

Brandon

Ok, you've been busy and I haven't been subscribed to this thread surprisingly. Fixed now, but sorry about the lack of a reply.

So on the hard drive magnets, I've noticed the newest/fastest drives actually had the largest magnets. I assume for accuracy and speed reasons to keep up with the higher rotation speeds. The one with a stepper motor was actually the oldest, circa 1993 and 43mb. The other 3, 10gb, 15gb and 60gb, that I destroyed all had "rare earth"/NdFeB magnets in them. I would assume Grade 42 as it's by far the most common. I see no reason to purchase more expensive grade 50 magnets.

I've been planning to order magnets from this site for over a year, just haven't ever done it. Never decided what all I wanted/needed. Their prices are the best I've seen though.
http://www.kjmagnetics.com/proddetail.asp?prod=DC2E

Radio Shack actually had 1 NdFeB magnet in store, it looked to be the same as this but it had absolutely no size/rating/grade at all other than saying "more powerful than ceramic". Oh, and it was $2 rather than 16 cents. Kinda why i went with the ceramic button magnets for the first try.
http://www.kjmagnetics.com/proddetail.asp?prod=D41

I really wouldn't worry about torque all that much. And I'll try to express why and the issues I had that didn't make my attempts yesterday successful.

The fan/motor had plenty of power to spin even with the extra weight of the magnets, both glued on and the ones in the container. My 2 main problems were, the magnets were just not strong enough to keep the stir bar in place above the center of the motor. Also, I was slightly off balance when gluing the magnets, so the rotation that was being transferred to the stir bar was not at all stable. It was constantly trying to whip the stir bar to the side of the container, and I wasn't off balance by much. Maybe 1/8", but it was enough to cause problems until the stir bar was up to speed and then it would spin smoothly. I think either dead on accuracy (I hate getting super glue all over my fingers, so i wasn't trying for perfection the first time) or simply stronger magnets would fix the problem.

Also, you wouldn't need to destroy the fan. I just glued the magnets to the fan, didn't cut a thing off.

Um, if I ever did anything crazy like this with the sub magnets I'd probably both weld and bolt them down to 1/4" plate steel. I don't even want to think about how much force 2 15lb objects spinning at 1000rpm is.

Now on to the other things you said. :)

Most of the mods I've seen use disc magnets but 2 small bars would probably work too, but I think discs are generally cheaper. Just make sure to get axially magnetized. I've seen radially magnetized discs, but they're rare.

If you've got a corded drill to throw away go for it. :)

I like the blender idea if you can find one for 5-10 bucks as it already has the built in speed control and obviously no torque issues. But a warning on it, you'll definitely know when your kalk is being stirred. :) If you try a blender, would you even need magnets? Something to think about. Most blades are SS I believe and possibly reef safe. Hmm, now you've got me thinking. I wonder if there are any commercial blenders, mixers, smoothie makers, etc that use all plastic parts for anything exposed.
 
Thanks for the replies, man. No need for apologizing for writing too much... I never do! :D :lol:

Anyway, I think the biggest single issue will be magnet strength as it can overcome (at least in my mind) a multitude of other problems. I think using the neodmyium magnets and centering them on a 120mm fan may very well do the trick really well. I'll probably go ahead and order some stuff tonight... maybe... :)

And I thought about the blender thing a little later... those things are LOUD. Don't think the wife would go for that... so computer fans it is for now... maybe I'll give a 90mm a shot instead of using my good 120mm. :)

Brandon
 
You can't swing it by explain to her that it will only make that noise for .07% of the day? 1 minute of mixing every 24 hours should be plenty.

If you do order from KJ, these should be plenty strong.
http://www.kjmagnetics.com/proddetail.asp?prod=D82

If you wouldn't mind, whatever you choose order a couple extra and if they work I can get them from you at the meeting. If the ones you get don't work I'll order some stronger ones (along with a few other magnets I've been wanting to get) and you can get them from me at the meeting. Would that work for you? Shipping is going to be the bulk of the costs which is why I've been trying to avoid it.

Too bad none of their magnets are rated at any distances, an "ie, 1/2" would be perfect.

And if anyone is curious, this is the strongest magnet K&J carries.
http://www.kjmagnetics.com/proddetail.asp?prod=BZX0Y08&cat=11
Plenty strong enough to break/crush a few fingers or entire hand if you had 2 to play with.
 
Sweet... thats fine. I can order a few extras if I order. I'm not 100% sure that I'll be able to, but we'll see. :)

BTW, they have a calculator that estimates pull of their magnets at certain distances. :) Something to play with, anyway.

Also, there are some 3"x3" cylindrical neodymium magnets on eBay that have a pull force of 890 lbs or something crazy like that! Its kind of scary.

Oh, and these magnets may also be great for frag racks... the epoxy coated ones, anyway... :)

We'll see...

Brandon
 
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