Defying Gravity - HUGE Neodymium Magnet vs Copper Tube Experiment - The Power of Lenz's Law!

[@robinson-foundry]

If you're interested in any of the tools or equipment I use and you want to help support the channel then don't forget to check out some of the affiliate links in the video description. Thank you for the support!

[@RandallEnglish-nf7wq]

??? IS THAT a beer keg you modified dor a keel ??? It look's cool lol , oh and maybe you can get like grind dust to show the magnetic field some how.

[@DIREWOLFx75]

When pouring metal like that, try doing it along the LENGTH of the mold instead of the width, that gives you a LITTLE bit more margin for errors. Also, something i know my cousin did, put something right next to the mold that you can rest the container on while pouring, as this reduces unintentional movements as well as letting you reduce the amount of weight you have to deal with constantly. Alternatively, you could try a spout or some other kind of pouring mechanism. . Awesome little experiment. For all of us who had not previously seen this kind of experiment, this was great fun.

[@KuramaKitsune1]

if you think of a magnetic field as a physical object, it becomes easier to understand, picture it like an invisible eggshell or a rubber balloon. you can apply force to an eggshell or a balloon . or grab and hang an object off of a stationary shell or balloon, and no "work" is being done by the field itself, why does a magnet stick to a fridge door with no power source ? well when you stick a pin into a wall, it is held there physically, and the magnet is as well with its field, no further work is being done

[@primo8825]

what would happen if you run electricity through the copper? I imagine you would be able to control the magnets position

[@FindanDandy]

make your own lathe, Mill and shaper like Dave Gingery books- you're already halfway there with your forge. Not difficult, just time consuming. Gingery uses stacked plate glass as flatness reference accurate to sub thou (0.01 mm) vs granite toolmakers flat.

[@tothesummit5864]

I use small neodymium magnets in projects all the time and keep a variety of them on hand. People are amazed at the power of a 1/2" disc X 1/4" thick N52 grade magnet when I demonstrate them. And I keep a 1" N52 sphere and a 4' length of 1 1/4" copper water pipe on hand to demonstrate Lenz's law also. Even being familiar with it it never ceases to amaze me at how long it takes to drop through. That 3" magnet you are playing with is a monster. Be vigilant with it especially around the other large magnet. By the time you realize you made a mistake you may have already lost a finger. I've had a 1" magnet bite me pretty good and it happens fast.

[@akyhne]

The magnet in the video is tiny compared to what the KZbinr Brainiac75 has.

[@Jonb173]

It’s true I lost 2 fingers to magnets.

[@souljunkee33]

​@@Jonb173thank you for sharing😢 that's intense I have had a magnet bite me once that now I have rules. And I've told people does the big ones can take your fingers but I don't think they believe me... So I'm adding your anecdote and life experience to my spiel when I share and teach with magnets. So again thank you. I started this method of rulemaking after I was injured by a table saw from a kickback of MDF and it was actually a man that I worked with that had lost four of his 10 fingers to a saw in the shop that we worked at that cemented the ritual of rulemaking and rule rehearsal every time I turn on my saw!

[@reggenerator8]

And also its good to cover it in cloth and cartboard or something, while you walk through doors. You can simply forget that the frame might be made of metal, and boom injury or worse yourmagnet might crack xD

[@thomasmaughan4798]

I salvage magnets from hard disk drives; thinking I would use them as refrigerator magnets but they are MUCH too strong for that purpose.

[@stillwater62]

I cannot help but admire your shop. The beautiful Machinist Chest, the two beautiful wooden worktables, the sand blaster, the furnace, some of your equipment on the shelves, a really nice and very expensive shop to say the least. Thank you for making this wonderful video.

[@joentexas]

That chest is a Gerstner, the finest, just shy of a couple grand. You have good taste.

[@ScottJones-d7s]

Thanks for including the tube roll/levitation part! Clearly shows how the field acts like a fluid. Well done

[@alwayscurious413]

Nice one - the great engineer prof sir eric Laithwaite always maintained that EM fields best understood by thinking of fluid flow. I learned a lot from that one lecture of his I attended.

[@gangoffour6690]

I loved magnets since I was a very young child and have a large collection. I am now in my 60s and I was so excited when rare earth magnets became available. I have so many shapes and sizes and some that are to large to play with casually. Ive got bitten by some large magnets a couple of times. Luckily no broken bones but some massive blood blisters. Love your experiments.

[@theaquariancontrarian3316]

A furnace made out of a keg?!!! Brilliant!!!

[@w.rustylane5650]

I'm a model railroader and I use neodymium (rare earth) magnets in my open frame (Pittman) motors. It makes a huge difference in current draw and engine performance. Cheers from eastern TN

[@jagrutbhatt3301]

Really appreciate your efforts, time and expense ..for this experiment. Thanks👍👍

[@postcardshackpostcards2369]

This phenomena is used in elevators as a passive brake that slows the elevator car with powerful magnets passing a heavy copper plate. It is also used to assist a hovering rail line system which uses super cooled, powerful magnets. This principle could have many uses! Power generating, frictionless bearings, etc.-already in use. I would like to see it applied to automation and flight, if possible.

[@pk2712]

Subliminalvibes is absolutely correct . In Electrical engineering courses , it is taught that magnetic circuits such as the one demonstrated in this video are analogous to simple dc circuits . In a simple dc circuit I = V/R where the current I in the circuit is equal to the dc voltage V in the circuit divided by the total resistance R . In the magnetic circuit the magnetomotive force mmf which is supplied by the powerful magnet is analogous to voltage in the dc circuit , the flux phi is analogous to current , and total reluctance R' is analogous to the resistance in the dc circuit . We then have the magnetic flux is phi = mmf/(R') . Now flux phi , and reluctance R' in this last equation are very important . Flux is a measure of the magnetic flux flowing through the entire magnetic circuit . The entire magnet circuit includes the magnet , the copper , and the air gap . By far the largest contributor to the total reluctance is the length of the air gap . This means that in phi = mmf/(R') we want the air gap as small as possible to make R' as small as possible to make the magnetic flux phi as large as possible . You could have stuck with the smaller diameter puck magnet , and a thin copper tube with a small clearance 1-2mm would be very dramatic .

[@TomBrockington]

Similar to a DC choke right?

[@ErCanEverything]

Thank you for this great video Bro🙂🤝🤝🤝

[@rickeyburke2596]

Next time you should do this, try letting your copper cool naturally instead of quenching it. Your cystaline structure of the copper will be alot different, they will be alot tighter structure. Your eddy currents alot different.

[@brnmcc01]

Cooling copper slowly hardens and crystallizes the internal structure. Quenching and cooling it as quickly as possible anneals and softens the copper, all copper wire is annealed. I'm not sure that this makes the wire a better conductor so much as helps prevent the wire from work hardening and fracturing which would definitely not be good for electrical wiring...

[@ronaldweller7438]

😅😅

[@cackles1005]

It is true that slowly cooling will improve conductivity, but only partially due to physical structure. Rapid cooling causes high internal strain, which can cause macroscopic cracks, but also produces crystalline shear and can even prevent crystallization, resulting in zones of amorphism. Generally speaking, improving crystalline ordering improves conductivity, so a slower and more consistent cooling should result in higher conductivity. Shoving the whole thing in a bucket of kieselguhr for a week or two would let it cool as slowly as reasonably possible via passive means - a tightly regulated programmable kiln could lengthen cooling time even further.

[@SPHYNX99752]

Quench it in hot oil and then dip it in nitrogen to cryogenically stress relief the crystalline lattice. The cold alignment of the molecules helps.

[@vijaybhaskar5333]

I presume its air entrapment could be the issue here, some air vents in the mould would have helped. But as he explained this is not an issue for this application.

[@Tinman_56]

Here's a project and experiment for you. Take the magnet (ball, disk, bar,etc.) and a copper pipe/tube, wrap the copper pipe with transformer wire, connect the ends of the wire to an ammeter, and/or voltmeter and check for amps and voltage if generated and transferred from the coil to the meter. Turn the magnet over so that the magnetic field is reversed and see if the amps or voltage changes. LMK your findings!😊

[@donaldcarpenter5328]

AWESOME I want ANOTHER 20-30 years of LIFE TIME! I am TOO OLD to only be learning this NOW!

[@johnsmith1474]

You should have learned it in HS.

[@ab_khanayy]

@@johnsmith1474what an insensitive thing to say

[@SageCog801-zl1ue]

They say you are never too old to learn. I would just get out there and do it.

[@shaunmark1]

In 5 years you’ll want another 5… but you can’t get more time, so GO DO IT RIGHT NOW!

[@omarei]

You were born in 1953? Or 1928?

[@daveschroedersworkshop4479]

Very cool. They taught us about this law in college, but never demonstrated it so effectively! Well done!

[@thebrizzell]

I would have to say you did a very good job of pouring that

[@xopherzenitram]

One can certainly appreciate your casting skill. Despite knowing the physics behind its resistance, watching the magnet interaction action is oddly satisfying...👍

[@huhumm1617]

Your molds are cracking because the plastic is expanding during the burnout, you can get 3-D printing, filament, specifically for burnouts.

[@NightRunner417]

Also I think it would have fought him less if he'd printed more hollow, or totally hollow. A simple taper on the inside near the top and one could easily print it hollow with very thin walls. Bonus points for less overall material to eliminate.

[@richardkelley1646]

Plastic shrinks when it's heated !

[@NightRunner417]

@@richardkelley1646 Behavior isn't strict black and white like you want it to be. Anyone that works in plastics knows it has _stresses_ in it that cause it to _warp_ when heated past its glass transition temp, not just shrink. This is why casting plastic blanks into other materials is such a bitch. Take a simple model of whatever and heat it to say 210 and it won't just get smaller, it'll mutate in all kinds of crazy ways, bulging here and indenting there, and there's no telling where it will warp until it does. This is why low warp plastics are such a big deal in 3d printing. NOT LOW SHRINKAGE, low WARP.

[@Ropetangler]

I'm no expert on this subject, but could you use candle wax instead of plastic for your form , it should be easier to burn out without stressing your ceramic mold.

[@InsideOfMyOwnMind]

​@@RopetanglerThis is how jewelry (rings) are made. Wax burnout in plaster of Paris then pour the metal into the p o p mould. I used to work at a place that did that.

[@Qwentar]

Question: when pouring the copper into the mould, you went along a vector to the centre, fairly parallel to the diameter. Why not go more perpindicular, or tangential? Wouldn't going with the gap / opening afford you more leeway regarding splashing / sloshing / missing?

[@madcapmagician6018]

Idea... Polish you copper tube really well so it will spin on bearings laying down like u shoeed at 8:30 , but power spin the copper tube via belt connected to a motor so the tube spins and plce the magnet inside and see how stable the levitation is

[@erich_kubart]

I was going to suggest the same thing - spin the copper tube like rolling it on the table but in place to show the magnet hovering in the middle of the tube

[@starechomic]

I bet there's a rock tumbler that would work perfectly for that application. Would be cool to see

[@gorazd68]

This way you would end up building electric motor eventualy.

[@sadface]

@@gorazd68 Or a generator, which might be worse...

[@the_omg3242]

@@starechomic A rock tumbler would work, or 3d print a set of pulleys to go over the tube and hang it with a set of V belts from a rod in a drill.

[@GuyayeFusa]

your videos not only entertain, but they also educate!

[@choppergirl]

8:30 Put the copper tube sideways on a rock tumbler, that keeps the tube rotating, so the big metal disc magnet floats in it suspended for as long as the rock tumbler keeps rotating the copper tube.

[@Metal_Master_YT]

nice idea!

[@kevpatt]

What's interesting too is _why_ the magnet floats in the center when the tube is rotating: When the magnet is off center, the copper rotating past the magnet is going thru a _gradient_ in the magnetic field. That is, imagine a point on the tube approaching the magnet. As this point rotates, it gets closer to the magnet, then as it continues rotating away, it gets further away from the magnet. So the strength of the magnetic field that this point of copper experiences is constantly changing, and it is this _changing_ magnetic field strength that actually induces the electric current (and opposing magnetic field) in the copper. This opposing field tends to push the magnet away, and any part of the tube that is closer to the magnet will also push it away in the same manner. Thus, the magnet gets pushed toward the center. If the magnet's poles are oriented coaxially with tube (as it is shown in the video), there is actually no current induced in the rotating copper tube if the magnet is perfectly centered, as the field is uniform all around. Of course, gravity pulls the magnet downward, so it is always a bit off-center toward the lower part of the tube, which constantly pushes it back upward toward center. All of this is the principle behind homopolar magnetic bearings.

[@KeithT-s8k]

I wonder if the effect is the same with 2 semi circles or 4 quarters? This breaking any current/field between the 2 half circles..

[@jorgeescalantegonzalez1178]

Great job manufacturing the copper tube! Very well demonstrated and great show of Lenz's law! Congratulations!

[@andresdiaz2578]

This is a really great concept to illustrate magnetic braking, or other principles that involve eddy currents. In magnetic braking, this concept is very similar to how actual magnetic braking works. I always like to show off this scientific concept to friends and family, as they are perplexed on how a magnet could slow down significantly on a copper plate due to resistance through the creation of eddy currents within the copper plate. Anyways nice video!

[@dragoda]

Copper is really expansive. You invest a lot in this video. Well done!

[@mikw1809]

Especially if you heat them up

[@potatosordfighter666]

9:27 YESSSS I was thinking that would be a super cool shot just a few seconds before you did it. Having the string fall down at normal gravity speed while the magnet just slowly meanders down the pipe, so cool

[@alexabadi7458]

I like how you keep your work shop so clean !

[@petepeterson4540]

I have seen this Over a thousand times but like a moth to a flame I am ready to see it again

[@douglasboyle6544]

I'm exactly the same way, it is just such a crazy thing to watch.

[@brian8410]

Anton Petrov's channel just did a YT vid on why insects are drawn to light and it's probably not why you think...........in case you are interested.

[@unoriginalname4321]

Look up the block of aluminum being pushed over in a MRI

[@HenryDavis-qu4rf]

Pretty cool watching someone wonder about then play with natural phenomena. Makes ya think that if ya keep playing around with it all of a sudden a eureka moment will happen and some new insight will be realized. The answers are all there just waiting for the correct questions to come to mind. Fun stuff. Thanks for sharing.

[@AB1Vampire]

Awesome demonstration. Foundry skills galore.

[@Walrus444]

Thank you for firing that big copper together. Loved seeing the results I experimented on a smaller scale

[@lancethrustworthy]

Extra points for mic'ing yourself well, and for the good amount of provided light. Yay! I do wish you'd looked at Lenz's law more. Oh well.

[@NeilCrouse99]

3:34, ... I don't know why, but liquid metal has always fascinated me. It's like watching a campfire ... I get the same feeling of wonderment... *: )*

[@IIISentorIII]

That's because when we where cavemen we played around with liquid medals.

[@thomasthecrunkengine3512]

You should try making a simple squirrel cage motor with this setup.

[@piprnic1]

Been showing people this for years. It’s really cool anti gravity. The science behind it is amazing

[@RT-qd8yl]

Half the state of Florida wants to know your location right now on account of that chunk of copper...

[@Literally_Deez_Nuts]

Here in California too.

[@SansTheGoat]

...

[@RadioStalin]

All of Romania: am I a joke to you?

[@blurtling]

they havin copper problems?

[@RadioStalin]

@@blurtling Romanians are thieves is the stereotype

[@prashantkumar-pb5nc]

Thanks sir.. You clear my doubt of what actually magnet feels in copper tube... . I know that magnet get slows down in the copper tube... But i didn't know of what it actually feels to it... . And when you tell that it feel like viscous fluid.... I got clear of it.. 👌👌😇

[@robertparkinson2102]

Suggestions:- Degas the liquid copper. Buzz bars are made from Oxygen Free High Conductivity copper. Ensure the inside of the 3d print is vented to atmosphere before burning it out. Add a 3 to 4 inch diameter sprue on top of your 3d print where you poured the liquid in. This will help with pouring. Having a larger surface area to volume ratio it will remain liquid longer so keep feeding the part with liquid as the copper contracts and solidifies in the part. The hydrostatic head also helps with porosity. Add a similar diameter riser on the other side to vent the part while pouring and feed the part while solidifing. Chills are added to sand molds to make grains smaller. You want them bigger so wrap part and feeds in ceramic wool so it cools slower allowing the copper grains to grow big. Don't forget to cover sprue and vent after pouring. Cast at a higher temperature. Use molochite instead of silica from layer 2 or 3. It is a lot cheaper. If you are using E-glass cloth you could wrap the outside with it as it will soften and sinter at orange/yellow heat. As others have said reduce the air gap between the magnet and copper. See Ben's video on magnetic materials at Applied Science.

[@jeffjeff8562]

When you were spinning it in the center, you were basically making an eddy current motor. Your hand acted as the electric motor, the magnet acted as the, well, magnet, the copper tube acted as the effected motor, rotor. I worked for a metal stamping press company. We used huge eddy current motors. Very cool stuff.

[@randallrun]

Really? If this is the kind of weird stuff you do…..I’m totally IN!

[@whoaaanelly65]

We used a computer controlled c-core electromagnets and copper disc's around the edge of a 55lb flywheel as the resistance unit for a lab-quality cycling ergometer. It was (at the time) capable of simulating actual wind and road resistance algorithms with resistance up to 2000 watts and down to less that an ounce of pedal force. That was preceeded - by about 20 years - by a much smaller version, without the massive flywheel benefit, but was much more affordable. My bread and butter for over 30 years. Sadly, we were run by two very old guys (as smart as they were) who wouldn't leave the 1980's. But knowing what I do made me click your video. Eddy current brakes are cool.

[@paulkupperman7049]

Since the molds crack pretty much every time, why not use the fiberglass cloth while building up the layers? Not for every layer, certainly, but using that instead of the silica sand for one in the middle should help.

[@cheebee2659]

yeh i was thinking that superslurry stuff is shite too :D

[@iolithblue]

For what it's worth I agree, but it makes removal of the ceramic much harder after casting.

[@Vic-xg2kc]

Just a thought for you. When pouring it's easier to hit the target by positioning the spout left-right but not forward-backward, because the spout focuses the pour position L-R. The F-B accuracy is dependant on your flow control consistency, which is much poorer and especially if it's heavy. So pouring into an annulus should be done tangential not radial.

[@AdamosDad]

Years ago, I worked for a company by the name of Thomas & Skinner, we made transformers and magnets, a large neodymium magnet was on a workbench, ready to be packed for local shipping, a tow motor came too close and got slammed by it, very funny to see and scared the driver to death.

[@ScottJones-d7s]

Were you the driver?

[@AdamosDad]

@@ScottJones-d7s No I was a maintenance man that worked on a bench next to the magnet packer. Some things just make the work environment more fun.

[@chrisklutts4096]

The world needs more tinkerers. Thanks for the effort you put into your work.

[@powderdays7557]

You should make a tall 10 foot clear plexiglass tube that sits on top of the copper. Drop the magnet in the tube see how much it slows it down

[@tolstory]

Super cool the magnet and the copper tube with liquid nitrogen and the affects will be more dynamic.

[@franshartmann4007]

What do you expect to happen when using liquid nitrogen?

[@unperrier5998]

To ease pourring, next time you can try to turn the mould 90 degrees so as to pour into the long edge.

[@lawrencemanning]

I was thinking a small lip all around the od and id wouldn’t have complicated things much, but that’s probably better.

[@vell0cet517]

Impressive amount of time/money/effort to prepare for your experiment. Bravo!

[@NicoSmets]

7:55 You have made an induction motor. Thank you for sharing.

[@eswnl1]

Just need a rotating magnetic field.

[@redhoticaro]

I could watch this video all day long...so mesmerising!

[@kenpatton8761]

Nice, Seems like those old 1950’s SiFi movies with spinning flying saucers kinda knew how to stabilize those ships. Always wondered if the secret to flying saucers were magnetic fields…..something to think about. Cheers

[@raloed.363]

it is the secret. magnetic and electric fields are the two most basic foundations of everything in existence. Even light itself and hence time itself is made out of these two fields

[@williamogilvie6909]

That's a great demo. Like the "lost plastic" casting.

[@taitano12]

Reluctance or, more commonly, reactance are the words you're looking for. It's the resistance to changes in magnetic and current direction. It's mostly used in inductors that are paired with capacitors for frequency regulation and filtration. Lenz's Law makes it so that the magnetic field generated by a current resists change in the current's strength. It stores magnetic energy like a capacitor stores electric energy. As a current drops, the magnetic field shrinks at 90° to the wire it's flowing through. As it does, it crosses the sections of wire next to the section it's coming from, generating electric current. As the strength/direction of the current changes, the resulting magnetic field will create an opposing current. Regular changes in the current (the frequency) simply create an imperceptible delay in direction, but irregular changes, such as signal noise, end up "blending" for lack of a better term, into the dominant/resonant frequency. This was an oversimplification of what is happening, but proper detail would and does require a solid 10-20 pages of theory, maths and examples... You know. Like you'd find in a textbook. Or at LEAST an hour video, but more like 4-6 hours like you get in a week of Electronics Engineering lectures and demonstration in college. Plus the additional hours spent practicing calculations, circuit experiments, doing homework, etc. Most of your first year of EE is spent learning this stuff, averaging one or two physical parts per week; the theory, maths, and application for each. Ah, the memories. I can still smell the blown caps and fried transistors almost 20 years later. 😊

[@polosandoval]

Ah yes, the magic smoke...

[@HangarQueen]

Came to the comments looking for the magic word, "reluctance" -- before posting it myself. TY. :-)

[@marcmillis3867]

They didn't tell you about the "Energy carrier" .... A collapsible elastic solid... Magnetic energy= a rotation in a medium, électrostatic energy = a tension in a medium... So physical space is 1 positive tensionZ & 2 negative pressuresXY. And what we see is Weber's law of 1846....

[@jagrutbhatt3301]

I wonder ..amount of time, cost and efforts you apply for experiments.really brave ..kudos👏👏

[@MichHedberg]

Make a device that spins the copper, so that the magnet stays centred in the copper.

[@danielflynn894]

That's trippy how it slows the magnet down Also your furnace keg is amazing

[@BeefIngot]

Id like to see some experiments with electromagnets and this.

[@Josiah-X]

Wow, that is cool. I’ve seen experiments like this before. Try creating a copper flat sheet and create 3-D print mechanism deck holds at least six neodymium magnets of that size and spin it around and watch it levitate over the copper flash sheet. That’s basically magnetic levitation.

[@stdesy]

I’m surprised that magnet isn’t flying backwards to try to attach itself to the vice behind you

[@mrb2349]

I have a question. As it falls through the pipe, does the magnet's weight add to it? Let's say you put the pipe on a scale and it weights 20 lbs, and the magnet is 10 lbs. What would the scale read while the magnet is passing through the pipe?

[@Dr_Larken]

That’s actually a good question! Now I want to know the answer!

[@Calimuros]

You did a great job, dude! Congrats from Minas Gerais, Brazil!

[@excrubulent]

You're doing physics experiments and recording the results. That makes you a physicist, regardless of what any piece of paper says.

[@LightsCameraJake]

Rotating that huge copper cylender around that magnet very fast is how you generate heat and electricity. This is exactly how electrical plants generate their electricity is by doing what you were doing in this video. Festinating stuff.

[@llllllllIIIIIIIIIII]

Gravity is a misconception. It is magnetism. -Ed Leedskalnin

[@BeatLyric-ox4cm]

Mangetism is the oppisite of Electricity - Terrance Howard

[@peterlindner3283]

Thank you for spending so much time and money to do these experiments. Pretty well exhausting the topic.

[@korundum4992]

"Eventually, we will get to the bottom of this!" ... :) ... that was a great idea ... to see the magnet slowly falling, rather than waiting to see it coming out at the other end of a thin copper pipe!

[@aydenquincy1847]

Love the kiln! If the tube had a bottom and lid and its contents were light enough you would be able to roll the "tube" with the pull of the magnet, right? Maybe even for some distance?

[@ecrusch]

Actually being able to SEE those forces at work is so much better. Thank you for your hard work. Eric in Kissimmee

[@cecilhampton3910]

Those big magnets are a accident waiting to happen, keep out of reach from visitors and electronics. Enjoyed the video!

[@miguelcastaneda7257]

Kinda wonder about delivery man

[@jonetyson]

Someone could easily get a body part instantly crushed by one of those magnets, and then get stuck, unable to get the magnet off. Beware. On the up side, it would probably rip off any ferromagnetic underwire bra that gets nearby.

[@paul41to45]

Love this, could you put the copper cylinder on a turntable and suspend the magnet at a certain RPM? Just a thought

[@ronaldellis3888]

That is such a cool experiment. I appreciate how much work it took and how many steps were involved for you to make all of this happen. I can’t help but think that this is tied to anti-gravity propulsion in some distant way it also makes me think, as capable as you are at making things you wouldn’t want to get on your bad side if you know what I mean lol.

[@nln1515]

Thanks, very interesting ! One cool thing would be to put your copper cylinder horizontaly on 4 rollers with 1 or 2 rollers powered by an battery drill so it can spin and with the magnet in the center, as far i can see with your short demonstration, i think the magnet will levitate into the copper cylinder. Would be cool and love to see that.

[@TorstenHoff]

One of the coolest uses of eddy currents is in the braking systems for some roller coasters. They result in a fail-safe, unpowered, wear-free system that will quickly stop the cars as they approach the end of the ride.

[@MoshePGuedes]

Shalom! Great experience. Suggestion: Place the magnet on a shaft with a variable speed motor. Measure any loads that may arise between the copper tube and the motor shaft.

[@martingannon132]

Magnetic fields are a really fascinating phenomenon. That resistance that is displayed when the magnet moves inside the copper tube creates eddy currents which creates heat.

[@Luckypinky83]

I am a new subscriber to your channel. I really enjoyed your video. Thanks for taking the time to produce it.

[@robinson-foundry]

You’re welcome! Thank you! I’m glad you enjoyed it.

[@glasslinger]

You can purchase rolls of copper shim stock. It is only slightly more expensive than solid copper bars the same weight. With the shim stock you can roll up "tubes" of any size you like. I would be interested to see if the magnetic effect varies with the thickness of the wall of the cylinder. Also, making a cylinder of shim stock with the layers insulated with paper, or even paint, and being able to short the inner end to the outer end to see if varying the resistance of the short has a large effect on the impedance to the magnet moving.

[@zapa1pnt]

I'm a little late but need to say, the difficulty you had, pouring copper, into the mold, @3:23, was the fact you poured perpendicularly, to the slot, instead of parallel, to it and kept over and under shooting it. 😁✌🖖

[@MadDragon75]

That old turntable in the attic would be fun to use as a base to put the copper on. And a drill and some imagination for the neodymium. 😉👍 I would experiment with that stuff for months.

[@BeatLyric-ox4cm]

Thanks for this you did alot of experiments i needed dont and feel prove my invention will indeed work as anticipated. THANKS

[@ferdinandnicoletti3625]

Outstanding. Thank you. I have not read others' comments. I assume that if the copper tube was air cooled slowly rather than placed in water the copper atoms would align and assign themselves into a more continuous regular 3D metallic lattice rather than the likelihood of vacancies and discontinuities. Hence, (rhetorically speaking) would the sea of valence electrons from a more continuous 3D structure of copper atoms contribute to greater eddy currents, and therefore decrease the speed of the magnet further? I am also thinking that any differences (between air cooled versus water cooled copper tube) may not be that noticeable.

[@prazuch5724]

I just discover your channel. it has a soothing effect. I love to watch.

[@kevpatt]

@robinsonfoundry that is a really awesome project and demonstration! The amount of resistance or "coupling" between the magnet and the copper is obviously influenced by the strength and size of the magnet, but it is also a factor of the smallness of the gap between the magnet and the inside of the copper tube. If you have a cylindrical magnet whose diameter is very close to the inside diameter of the tube, the effect will be even more dramatic. You might consider re-casting your copper tube so the inside diameter is just a bit larger than your magnet, say 3.125".

[@strokedformula1977]

These eddy currents display a really cool effect

[@joentexas]

Did a couple years at Home Depot in the plumbing department after retirement and would dazzle the kids with 1/2" magnets and 2' of copper tubing. I tried to measure voltage on the pipe since you and I are making electricity but my meter was not sensitive enough. Your pipe and magnet might be large enough to get a reading. Try measuring DC voltage from the pipe to a ground. You might get a reading. Fun stuff, cool video. Thanks.

[@jskjsk3986]

I've seen this effect before, however you stepped it up. Nice.

[@gonzalez7805]

Looks like a good way to transport/store a magnet... Are there better ways ?

[@MrDumonic]

This would be an awesome re-design of the drop zone ride. Have one big long pipe with sections of copper and glass. When you hit the glass portion you drop fast, then the next portion is copper, so it slows you down. You could design it to speed up and slow down. The last section near the ground would be copper and bring you to a stop. It would be the safest ride in the world!!

[@emmanuelespinoza2532]

It's been 10 years since I saw that, it's great!

[@danylosokolov2085]

Very cool physical effect, thank you for the efforts of making this nice and important video, keep up

[@antonnym214]

Nice demonstration! I would be interested, if you make more of those copper tubes, you could join them and make a longer tube.

[@jamesraymond1158]

Fun to watch. Wonderful having the right tools. What would happen if this were done on the moon? Would the magnet just fall more slowly, or would it remain suspended?

[@Adrian_Galilea]

Rotate the copper tube with the magnet inside like in 8:30, with a mechanism similar to a tumbler, let's see if you can make it levitate and how slow it needs to go for that.

[@WoodstockDz9]

1:54 - "...a really durable ceramic mold." 3:59 - "...now I get to break it apart..."

[@vajrapaniom7410]

Could you try wrapping a coil around the copper tube and apply a voltage to see how the magnet behaves?

[@HouseGuide]

I haven't seen all your experiments but can't you come up with something practical or some amazing awesom toy or something revolutionary.

[@gregoryclifford6938]

I loved the gyro comparison. Does that effect fail at 1500degrees in the way that heat treated steel loses its magnetic properties?

[@kumardigvijaymishra5945]

3:10 You could hold the crucible near the top rim with metal bar, and use that as a hinge while tilting crucible with another tool from the base. It might be better to hang the first tool with some rope from ceiling to bring it to a height suitable for pouring inside the mould.

[@mikalrage7316]

When you were pouring the molten copper into the cylinder casting, you had it aligned at the most difficult angle possible in terms of getting the copper into the narrow opening. Some overshot the opening and some fell short. It will be easier if you align the casting at an angle so the metal is pouring at a tangential angle to the opening rather than a perpendicular angle. The opening in the casting will have more margin for error in the direction of flow, allowing for more variability in your rate of flow (how far you tip the crucible). Of course, having some sort of funnel build into the casting would have helped even more.