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Mister Earl
2010-Feb-11, 08:32 PM
Getting kinda bored lately, and I had a lot of fun with magnets when I was a kid, so I went ahead and did some shoppin'. I bought me 200 small steel ball bearings and 200 small neodymium rod magnets. Should work out pretty well, I think. Keep the ol' brainpan busy when something more important isn't going on.

mugaliens
2010-Feb-11, 09:15 PM
Cool!

When my son passed beyond the taste/eat/swallow stage of his youth, we bought him some commercial versions with which one could build some pretty elaborate structures. I don't recall the name of it, though I think I had just as much fun with it as he did!

RAF_Blackace
2010-Feb-11, 10:20 PM
"Magnetics" I think the commercial packs are called, my kids have thousands of them. Sure can destroy a vacuum cleaner in double time.

LookingSkyward
2010-Feb-11, 10:59 PM
Yup, Magentics (maybe magnetix). All over everywhere in our house. Great stuff!

Mister Earl
2010-Feb-12, 08:12 AM
Yeah. I didn't go with a set intended for constructing things. Seems like you pay too much and don't get that many pieces. So I bought steel ball bearings from a bike supplier, and the magnets from a company in the states that manufactures them. The neodymium rods are 1/16" dia. x 1/4" thick, and the ball bearings are 1/8" in diameter. 200 rods, 200 bearings. Cost me about fifty or sixty bucks. Should be enough to put together some elaborate stuff. Keep the brain warmed up :D

mugaliens
2010-Feb-12, 08:57 AM
Keep the brain warmed up :D

Exactly! And a right handy (inexpensive) approach, Mr. Earl!

pzkpfw
2010-Feb-12, 09:02 AM
Would like to see pictures when it's begun...

HenrikOlsen
2010-Feb-12, 12:53 PM
Just remember not to buy stainless steel balls:)

Mister Earl
2010-Feb-12, 06:58 PM
Just remember not to buy stainless steel balls:)

That's the scary part. They ARE stainless steel. The site I ordered them from didn't explain what nickel content they use, so I may end up with non-magnetic bearings. But, considering how cheap they were, I'm hoping they didn't go crazy plating them. So I think my odds of having useable bearings are 70-30.

"Inshallah"

aastrotech
2010-Feb-12, 07:24 PM
A warning about these new rare earth magnets.They are so strong now that they can be dangerous. My brother just visited with a set of these things. None of them over an inch in diameter. They can pick up a metal object from a foot above. Playing with them, pulling them apart and feeling the force. Lose your grip and they slam together and pinch the hell on you. Not for kids to play with. You can't help pinching yourself with these things they're that strong. You'll pinch yourself a lot just playing with them for a few minutes. Don't let someone hand them to you unless they are stuck together. If one is in your hand and one is in their hand and they lose grip, BAM!!! Even a jump of only 2 inches will pinch hard enough to draw blood.

Mister Earl
2010-Feb-12, 07:33 PM
Yes, but these are very tiny. Here's the link where I got 'em.

http://www.kjmagnetics.com/proddetail.asp?prod=D14-N52

They *are* rated at over 7k gauss surfance field, though. Should be neat.

Mister Earl
2010-Feb-12, 07:38 PM
Would like to see pictures when it's begun...

You got it, chief! I got all kinds of projects to do once I get 'em. Brainteasers, and the like. Here's a short list of the stuff I'm going to do:

1.) How tall a tower can I make using all pieces?
2.) What's the longest bridge I can build?
3.) Can I build a structure that houses a levitating component?
4.) Can I build a structure strong enough that it holds itself together if I roll it across the floor?
5.) Can I build a structure on the side of my fridge that'll hold the Ketchup bottle?

Stuff like that.

Swift
2010-Feb-12, 07:39 PM
I've had the experience aastrotech talks about, of pinching yourself, but I think the tiny ones should be ok. I would also keep them away from your wallet / credit cards / ATM card. They might even mess up electronics too.

LookingSkyward
2010-Feb-12, 07:50 PM
Break out that old copy of "Synergetics'...

Fazor
2010-Feb-12, 07:55 PM
I would also keep them away from your wallet / credit cards / ATM card.
I thought Mythbusters busted that?

Mister Earl
2010-Feb-12, 08:07 PM
I thought Mythbusters busted that?

They didn't use Neodymium magnets. They didn't have any handy at the time. Later, they showed an outtake where they procured one, and it did wipe the cards. 7,000 gauss is a heck of a lot!

Fazor
2010-Feb-12, 08:09 PM
They didn't use Neodymium magnets. They didn't have any handy at the time. Later, they showed an outtake where they procured one, and it did wipe the cards. 7,000 gauss is a heck of a lot!
Ah. Well I'll be sure to keep them out of my wallet then.

I must be more evil. I'd be trying to figure out a way to make a mag-rail gun. :)

Mister Earl
2010-Feb-12, 08:12 PM
Ah. Well I'll be sure to keep them out of my wallet then.

I must be more evil. I'd be trying to figure out a way to make a mag-rail gun. :)

I know very little about electonics, regrettably. Otherwise I'd be doing robo-wars style robots. I've had ideas on how to win for probably a decade.

Mister Earl
2010-Feb-12, 08:18 PM
Then again, if you had a plastic tube with two wires on opposite sides on the inside of the tube, loaded it up with a little piece of metal, and then pumped a huge voltage into those wires, wouldn't that shove the piece of metal out of that tube? I vaguely recall hearing something about that somewhere.

Mister Earl
2010-Feb-12, 08:28 PM
Here's the stats of the magnets, for other magno-philes:

# Dimensions: 1/16" dia. x 1/4" thick
# Tolerances: 0.004" x 0.004"
# Material: NdFeB, Grade N52
# Plating/Coating: Ni-Cu-Ni (Nickel)
# Magnetization Direction: Axial (Poles on Flat Ends)
# Weight: 0.00333 oz. (0.0943 g)
# Pull Force, Case 1: 0.19 lbs
# Pull Force, Case 2: 0.20 lbs
# Surface Field: 7343 Gauss
# Max Operating Temp: 176F (80C)
# Brmax: 14,800 Gauss
# BHmax: 52 MGOe

LookingSkyward
2010-Feb-12, 10:20 PM
I have an OLD hard-drive magnet stuck to my fridge...not sure of the specs, but it was strong enough to tear the hip pocket of my Levi's when it snapped on to a filing cabinet I leaned against :)

Mister Earl
2010-Feb-12, 10:25 PM
Interesting fact: 200 of these tiny neodymium magnets weigh roughly .04 pounds, but can lift roughly 38 pounds. So that tells me 1 pound of these neodymium magnets could lift 950 pounds! All I need to do is work out a way to use these to become some kind of arch-villain, and I'll be set.

LookingSkyward
2010-Feb-13, 12:08 AM
You'll need a blimp....

HenrikOlsen
2010-Feb-13, 12:44 AM
I have some too, got them from http://www.forcefieldmagnets.com/catalog/ they don't seem to have as many different kinds available anymore. At the time they had graphite blocks (diamagnetic) to make levitation setups so I got a couple of those too.
The largest they had at the time were 1"x1"x2" blocks, they required proof of age before shipping those because they're easily powerful enough to cause considerable damage if allowed to slam together with a hand in the middle.

Various uses for strong magnets http://www.wondermagnet.com/uses.html

That have a couple of pics for the application you have http://www.wondermagnet.com/bsculpture.html

As for lifting they have a couple of pictures too http://www.wondermagnet.com/maytag_hang.html, http://www.wondermagnet.com/150demo.html

Mister Earl
2010-Feb-14, 06:55 PM
Should have the magnets by Wednesday. The bearings? No idea.
Looking forward to messing around with 'em.

kleindoofy
2010-Feb-14, 08:31 PM
What's all this talk about being bored?

I think the last time I was ever bored was when I heard the doctor telling my mother to press. Jeeez, hurry up, I got things to do.

Oh, no. It was back in 1978 when I was 19. I made the huge mistake of going to the movies to see Star Wars. Thats 121 minutes of my life I will never get back.

Don't get me wrong. Magnets are cool.

Mister Earl
2010-Feb-14, 08:59 PM
Eh. It's just how I am. I always have to have something mentally engaging to do. Being bored is insufferable. That's my one weakness. I've had bones broken, skin burnt, been in the ol' gas chamber in boot camp, endured a summer in Iraq and Kuwait, been stuck outside in the mountains at -30 degrees, and above all I'd say the worst is being bored.

GalaxyGal
2010-Feb-14, 09:51 PM
Then again, if you had a plastic tube with two wires on opposite sides on the inside of the tube, loaded it up with a little piece of metal, and then pumped a huge voltage into those wires, wouldn't that shove the piece of metal out of that tube? I vaguely recall hearing something about that somewhere.

Wishing you the best....but this post makes me wonder, is your life insurance paid up? :D

HenrikOlsen
2010-Feb-14, 10:03 PM
Then again, if you had a plastic tube with two wires on opposite sides on the inside of the tube, loaded it up with a little piece of metal, and then pumped a huge voltage into those wires, wouldn't that shove the piece of metal out of that tube? I vaguely recall hearing something about that somewhere.
Huge current, but apart from that you're right.

The problems include how to keep the current flowing while the piece of metal is sliding along the wires, that the current required is large enough to vaporize the projectile if there's even a little bit of resistance and if you want it as a battlefield weapon, how to transport the power plant.

Mister Earl
2010-Feb-14, 11:26 PM
Wishing you the best....but this post makes me wonder, is your life insurance paid up? :D

I've been electrocuted before, too. That one wasn't so bad, the current wasn't high enough to do me in. I did have a headache for two days, and I smelt of burnt hair for about a week.

Sam5
2010-Feb-14, 11:56 PM
I thought Mythbusters busted that?

The magnetic strip on the back of a credit card is coded with magnetic signals, very much like an old 1/4-inch audio tape is coded with voice and music.

Back when the Bart subway first opened up in San Francisco in the mid to late ‘70s, word quickly went around that Bart cards (which were flexible cardboard with a magnetic stripe on the back) were being counterfeited. I used Bart occasionally, and one time I took my card out of my wallet and taped it to the drum of my magnetic audio track sound reader (a gadget used to listen to the audio on 16 mm film that has a magnetic sound track).

To my surprise, when I rotated the drum, I heard different beep tones, very simple tones, and then I knew that the Bart cards had a simple beep tone code recorded on them. The stripe was very much like a short piece of 1/4-inch tape. The tones could have been easily duplicated.

I think later, credit card companies and maybe Bart too, went to multiple tracks with more narrow tape heads. I never listened to my credit card tones, since they were not flexible and would not fit over the drum of my sound reader.

GalaxyGal
2010-Feb-15, 12:18 AM
by Mister Earl
I've been electrocuted before, too. That one wasn't so bad, the current wasn't high enough to do me in. I did have a headache for two days, and I smelt of burnt hair for about a week.

a very cautious LOL - been the burnt hair route - not due to electric current, but propellant. Now considerably older and minimally wiser, much more risk adverse.

My husband and I met in Experimental Development at a plant that made propellant. We hand-carried Nitroglycerin together (how romantic!). While dating, we used to make rockets for fun. Not unlike the early experiments from the movie 'October Sky', ignition sometimes became detonation - esp if we were heavy handed on the HMX in the propellant. Some of our most spectacular launches resulted in a series of spiraling explosions in every direction (including where we stood) and sparkling debri falling over a wide arc.

To this day, when he says "Honey, I have an idea..." I reflexively check our policies. ;)

....but we digress

pzkpfw
2010-Feb-15, 12:22 AM
3.) Can I build a structure that houses a levitating component?

I've always liked the idea of a globe that levitates.

Getting the right repelling / attacting forces figured out to give the best (largest) distance between globe and "supporting" structure might be a brain teaser...?

Mister Earl
2010-Feb-15, 12:45 AM
My idea on that was to make a concave structure, with the inward facing points all north or south poles. Then, I'd make a ball where the outside was the opposing pole. That way, even if levitation is achieved, the concaveness of the supporting structure would help hold it in place.

Sam5
2010-Feb-15, 01:20 AM
You be careful and not create something unique some unique shape or unique magnetic field that might blow up the earth or sink the continents!

Back when I was a kid, I used to see sci-fi movies about guys like you, experimenting in your labs.

:)

http://vanessabertozzi.com/frankenstein_presents/images/frankenstein_lab.jpg

http://www.paper-dragon.com/1939/images/lrg_death_ray.jpg

Mister Earl
2010-Feb-15, 01:22 AM
I'll just be building stuff with magnets. That's not nearly as threatening as my Quantum Metastability Event Initiator. That one I don't even want to run a diagnostic on. I don't even let it get further than the power-on self-test.

HenrikOlsen
2010-Feb-15, 01:56 AM
My idea on that was to make a concave structure, with the inward facing points all north or south poles. Then, I'd make a ball where the outside was the opposing pole. That way, even if levitation is achieved, the concaveness of the supporting structure would help hold it in place.
You know it's been mathematically proven that a static setup of magnets and ferromagnetic materials can't be built to achieve levitation, right?

You'll need diamagnetic components as well or have the levitating bit spin stabilized.

Mister Earl
2010-Feb-15, 02:27 AM
You know it's been mathematically proven that a static setup of magnets and ferromagnetic materials can't be built to achieve levitation, right?

You'll need diamagnetic components as well or have the levitating bit spin stabilized.

Now THERE'S a challange! I think I can succeed. If it were just one magnet at the base and another for the levitation component, then I would expect it to fail every time. But with multiple, for both the base and the levitating component? I think I can succeed. The trick, I think, will be constructing both the ball and the base to where there's less freedom of movement, keeping the opposing poles in close proximity.

mike alexander
2010-Feb-15, 03:55 AM
I have a decent collection of magnets from the replaceable toothbrush heads used in the Sonicare toothbrush. Strong little buggers, and sort of lagniappe for keeping your teeth clean.

SkepticJ
2010-Feb-15, 04:28 AM
I think it'd be cool to take NIB magnets on the scale of this (http://www.kjmagnetics.com/proddetail.asp?prod=DZ0Y0) and build a Back to the Future-esque subwoofer.

mike alexander
2010-Feb-15, 04:37 AM
I have one of those round loudspeaker magnets I use to demonstrate how a mass spectrometer works. I roll different sized ball bearings down an incline next to the magnet and it whips them around to a greater or lesser extent depending on the mass. Touchy to set up, but quite cool when it works.

SkepticJ
2010-Feb-15, 04:48 AM
Ferrite magnet?

A NIB that big would be a hand-breaking beast.

Tom Servo
2010-Feb-15, 05:58 AM
Hey Mister Earl thats an awsome site you found.

Im thinking that I just might make a purchase also.

I have seen countless designs for "free energy perpetual motion machines" that involve magnets of diffeent shapes and sizes. Would be cool to build one just to show the youtubers that these machines dont work.

Anyway If you make something neat out of them you should post us some pictures.

Mister Earl
2010-Feb-18, 04:25 AM
Well. Today was rather irritatingly magnet-less. I guess I'll get them tomorrow.
EDIT: Never mind. Apparently, the parcel was shipped from texas to texas, labelled as incorrectly routed, then arrived at a third city in texas. It's still in texas. So it'll be a day or two I think. Unless they re-ship it elsewhere in texas.

GalaxyGal
2010-Feb-18, 11:02 AM
Does Texas have a magnetic force to be overcome by the shipper? :D

Fazor
2010-Feb-18, 04:18 PM
Does Texas have a magnetic force to be overcome by the shipper? :D

Ha! Now I keep picturing them loading up the box then turning around, only to have the box slide back out of the truck and into the warehouse. Of course, the shippers have to be tv-sitcom dumb. "Jeeze Fred, how many of these boxes do we have to load?" [as Billy-Ray loads the same box for the nth time.]

DonM435
2010-Feb-18, 06:59 PM
... when I rotated the drum, I heard different beep tones, very simple tones, and then I knew that the Bart cards had a simple beep tone code recorded on them. The stripe was very much like a short piece of 1/4-inch tape. The tones could have been easily duplicated.

I think later, credit card companies and maybe Bart too, went to multiple tracks with more narrow tape heads. I never listened to my credit card tones, since they were not flexible and would not fit over the drum of my sound reader.

Remember the old pay telephones, in which you deposited coins to pay for long distance calls? I'm told that they relied upon the sounds generated by the coins dropping through the machinery to determine how much you'd just deposited.

Some genuises figured out that you could tape-record the coin tones and play them back whenever you needed to. So, when the operator said "Please deposit $2.35," the guy would use his portable tape recorder to play back nine "quarter" sounds and one "dime" sound. Thus the operator figured he'd paid (or maybe some device assessed the tones), though the call was actually free.

Fazor
2010-Feb-18, 07:04 PM
. . . the guy would use his portable tape recorder to play back nine "quarter" sounds and one "dime" sound. Thus the operator figured he'd paid (or maybe some device assessed the tones), though the call was actually free.

If I remember the documentaries on 'hackers' that were popular around the time of the movie, "Hackers" (go figure); these pay-phone tricks are oft considered the birth of "hacking". Or was it "cracking"? Or whatever.

Bobbar
2010-Feb-18, 07:38 PM
I think it'd be cool to take NIB magnets on the scale of this (http://www.kjmagnetics.com/proddetail.asp?prod=DZ0Y0) and build a Back to the Future-esque subwoofer.

Those things are horrifying!


We go through quite a few hard drives at work, and I'm always compelled to take every single one apart. (We also have been known to destroy them with various high-powered weaponry)

I pulled these bad boys out of a first generation Western Digital Raptor, I use them as my pen, screwdriver and...piston assembly holders. :lol: They are very much impossible to rend asunder without something to pry them apart with.

http://img697.imageshack.us/img697/1940/20100218141210.th.jpg (http://img697.imageshack.us/i/20100218141210.jpg/)

http://img716.imageshack.us/img716/8831/20100218141248.th.jpg (http://img716.imageshack.us/i/20100218141248.jpg/)

Yes, those are .44 caliber sized holes in the patters. ;)

I received quite a few blood blisters over the years from these kind of magnets. I wouldn't even touch one as big as the ones shown in SkepticJ's link. VERY dangerous.

Mister Earl
2010-Feb-19, 02:11 AM
If I remember the documentaries on 'hackers' that were popular around the time of the movie, "Hackers" (go figure); these pay-phone tricks are oft considered the birth of "hacking". Or was it "cracking"? Or whatever.

Blueboxing, pearlboxing, phone phreaking, ect. That wasn't the trick though. Some kid way back in the day figured out that a whistle in a captain crunch box emitted a perfect X htz tone. Ma Bell back then used that tone as part of their system. By blowing that whistle, then dialing, you could get free calls. Later, someone found out that when you dumped a quarter into the machine, it would send a tone down the line letting the office know you'd put in a quarter. Unfortunately, it also played that tone out of the earpiece.

Simple trick: Get about $5.00 worth of quarters, hook up a recorder, and dump them in. End the tape, hang up, get money back. Pick up phone, play tape into the mouthpiece, and you were set.

On certain payphones, there was also an easier way: Unbend a paper clip, touch one end into the mic, touch the other end on the keyhole for the cash box, and it'd short the system, giving you a free call. Also doesn't work anymore.

None of these methods work anymore. And why would you need to do it these days, everyone has cellphones.

Mister Earl
2010-Feb-19, 08:19 PM
Magnets arrived this morning. Good news: The magnets and ball bearings work great. Bad news: They're smaller than I thought they'd be. I got giant mutant-hands, so this is gonna be tough. I'm making my first structure now. There's enough strength to the magnets where I can go B-M-M-M-B (three magnets between bearings) or more, but I'm gonna start with B-M-B and see how I can manage it. I'm trying to make a little tower with it now, see how strong it holds together.

mugaliens
2010-Feb-19, 08:30 PM
None of these methods work anymore. And why would you need to do it these days, everyone has cellphones.

Unlimited US LD is standard with my 6-feature, crystal clear calling plan for $19.95 a month.

DonM435
2010-Feb-19, 08:44 PM
If I remember the documentaries on 'hackers' that were popular around the time of the movie, "Hackers" (go figure); these pay-phone tricks are oft considered the birth of "hacking". Or was it "cracking"? Or whatever.

Another case of hacking that pre-dates the ubiquitous computer: Some guy, back in the 1960s, borrowed a magnetic typewriter. He grabbed a stack of deposit slips from local banks and encoded his account number, invisibly, on these. Then he put the stacks back in the banks.

Thereafter, if anyone made a deposit using one of the doctored slips, a machine reading it assumed that it was a custom-issued slip rather than a generic one, and so deposited the money into this guy's account rather than kicking it out for manual processing as it was supposed to do.

I guess he eventually got caught, which is why we have the story.

Nick Theodorakis
2010-Feb-19, 08:56 PM
Another case of hacking that pre-dates the ubiquitous computer: Some guy, back in the 1960s, borrowed a magnetic typewriter. He grabbed a stack of deposit slips from local banks and encoded his account number, invisibly, on these. Then he put the stacks back in the banks.

Thereafter, if anyone made a deposit using one of the doctored slips, a machine reading it assumed that it was a custom-issued slip rather than a generic one, and so deposited the money into this guy's account rather than kicking it out for manual processing as it was supposed to do.

I guess he eventually got caught, which is why we have the story.

Wasn't that one of Frank Abagnale's ("Catch Me if You Can") scams?

Nick

DonM435
2010-Feb-20, 10:19 PM
Wasn't that one of Frank Abagnale's ("Catch Me if You Can") scams?

Nick

I don't know. I've forgotten where I read about it.

Tobin Dax
2010-Feb-20, 11:17 PM
I have one of those round loudspeaker magnets I use to demonstrate how a mass spectrometer works. I roll different sized ball bearings down an incline next to the magnet and it whips them around to a greater or lesser extent depending on the mass. Touchy to set up, but quite cool when it works.
You posted this a week ago. I just gave a lecture that this would be useful for this week. I'd also forgotten about it since the last time you posted. I'm now rather angry at myself. :mad:

Mister Earl
2010-Feb-21, 06:53 AM
No pictures yet. I got a video camera, but cannot locate the power cord for it, and the battery is empty. Gonna root around more in the morning for it. Then I'll YouTube up some stuff.