It's not the size, it's the _GAP!_ Clearance of 1-2mm all-round will slow the magnet way more than 3-4mm. 👍😎 In your last video you can see how a thin plumber's pipe with a small gap to the magnet is MORE effective than a thicker copper pipe with a larger gap.

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

A suggestion for you from a guy who has (probably) no experience with any of this -- look at the video @5:25. You have placed a constraint on yourself by pouring into the smaller gap in the mold. I suggest you rotate the mold 90 degrees so you can pour into an opening several times larger. I follow this recommendation while pouring cement from a mix truck off a chute and into a foundation form. I guess I have many tons of experience with this sort of thing after all! Excellent video.

i am glade you are being less camera shy and good job with all the videos.

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.

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

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

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

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

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.

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

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.

Awesome demonstration. Foundry skills galore.

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.

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

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

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

Super chill the copper and the magnet.

NICE demonstration ！！！I believe this is the true beauty of experiments which you can never imagine with mere theories and excercises on the textbook!

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.

Wonderful demonstration of your kiln work n magnetic magic

Amazing work Rob, love you

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.

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!

Wow! Really impressed w the way u did everything, such a cool effect

Sweet - what a beautiful example!

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

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

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

Just mind-blowing. Wonderful.

You can use the same phenomenon to launch aluminum discs from the top of a flattened conductive coil when AC current is applied. A thin rod is usually placed in the middle of the setup to constrain the motion of the aluminum disc, otherwise it will tend to simply slide off to the side. Aluminum is better for this since the metal is less dense than silver or copper. The conductive coil can be made from some copper wire. Nothing fancy is needed, just a switch or a voltage controller and conventional residential wall power (standard 60 hz 120 v AC works fine).

These eddy currents display a really cool effect

Thx for the video!

Always get excited when you’ve uploaded

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!😊

Nice enough to suggest where to skip ahead to... I subscribed immediately. Thanks

Wtf, this video has been uploaded 15 hours ago but the first part of the video is a complete dejavou, including the crack and fiberglass. 😮

I really like restoration videos. That, and a powerful case of OCD led me to suggest chucking the copper tube on a lathe, facing the ends, OD, and ID, and then polishing them. That would be so cool if you have the tools.

Cool! I enjoyed the watch! you should definitely try to find a way to purify that silver, sterling silver isn't pure enough, and you need close to 100% purity to take advantage of the extra conductivity.

You share your mind . We learn from you thank you .❤

Good usage of appropriate safety equipment 😁

Gran video. Además de un laboratorio con muchos recursos, mucha valentía en realizarlo.

Thank you for this great video Bro🙂🤝🤝🤝

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

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. 😊

I like your Anheuser-Bush melting furnace!

Fun video. If you were to rotate the mould through 90 degrees and pour along the length of the opening the casting process would be a little easier. Great video though, and good to see you onscreen!

I enjoyed seeing this done at this larger scale. One thing I can think of is to put the copper tube horizontally on rotating rollers , then see if the magnet floats in the center.

it gives hints and ideas to do some thing further

Magnets are always fun. But this is super cool. Thank you from us without kilns and all that to try it ourselves.

Awesome ... reminds of when I worked in a Gold Refinery !!!

This was SOOOO COOL

This is really interesting. Maybe you could suspend the larger copper tube onto a vee block with roller bearings as contact points and spin the copper tube to try and get the large magnet to float in the middle. Great video!

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

Nice work brother!

Great work @

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.

Great video! I really loved the part at 8:05

I will NEVER skip the slurry!

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!!

That is one dream hobby/DIY shop

A suggestion id like to see... If you put a hand scale on the rope and pulled the magnet through the copper to see the resistance in pounds/grams. I enjoyed the video and your effort😊 thanks 👍

Now that is WAY COOL!!!

It's more fun than anything I saw in the school or university.

Definitely make the ID size more exact to the size of the OD of the magnet if you want to see the best results. The closer the better. That's why a magnet that's literally sitting on a copper sheet then sloped at a near 90° angle will move extremely slow.

I've heard about eddy currents. This is way cool on a grand scale!

Excellent video! I'm now a fan and just subscribed. I noticed a few comments suggesting you put the copper tube on its side and rotate it in order to see just how well the magnet levitates -the rock tumbler idea sounds cool and very simple . Can we expect to see a video like that any time soon? Really great job!!!

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.. 👌👌😇

Show us the 400 kg pull of your magnets various ways , nice video . I like your work

Magnetic bearings would be insane on so many levels

I'm not boasting or anything and I know those magnets are massively powerful, but their power does not extend far from their surface. I used to be an MEI and CT Scanner engineer and we got to play with truly awesome magnets. We used to get the junior doctors to hold part of the aluminium safety rail and literally RUN at the magnet. They would never get there, because the magnet would slow them down to a crawl before they hit it. MRI's are fun, just a bit unforgiving.

It might be fun to attach a voltmeter to various parts of that tube to see what currents are being generated as the magnet falls.

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.

I propose to create a Gauss gun, where using the casting method you can create a powerful induction coil with a relatively small number of turns but a large wire diameter. One formula that describes the inductance (L) of the coil is: L = (N^2 * μ * A) / l Where: L is the inductance in Henry (H), N is the number of turns, μ is the magnetic permeability of the medium (for an air coil, approximately equal to μ0, the permeability of vacuum), A is the cross-sectional area of the coil, l is the length of the coil. This formula shows that to achieve a higher inductance, you can either increase the number of turns (N), or compensate for fewer turns by increasing the cross-sectional area (A), which includes using wire with a larger diameter. Thus, increasing the wire diameter with a small number of turns helps create a powerful induction coil

Nice experiment. It would be nice to see the copper suspended in space with the magnet spinning inside to see if the copper will also spin with it

8:05 "there's so little resistance" is actually the correct thing.

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

Excellent video.

It seems there must be a way to free energy along this thought process.

Thanks for sharing.

excellent 👌 perform ❤ this is a future of our next generations technology 👈😊😊😊

Very good

@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".

Cool as hell

You remind me of the original creator (RIP) of the channel The King of Random in all the best ways possible

That's cool 😎 as heck

I imagine you have seen some of the older vintage foundry films like British Pathe’s ‘Casting In Iron’ and such. I have always been fascinated by the large hand wheel and gear systems that factories use to pour molten metal. I have been thinking about trying to build one of those for a few years but just don’t think my little jewelers electric foundry is up to the task of justifying the build. I feel like a pouring frame for heavy crucibles might be just the ticket for you.

I saw a video once of a guy heating up water with copper pipes and magnets. The magnets where on a sort of a rotor moving them past the copper pipes very fast. Resulting in the pipes getting hot. And that heated up the water. It would be cool if you could do something of that sort with the copper and magnets.

Another excellent video and experiment.

I used an 18" length of aluminium tube and an N52 sphere with a couple of millimetres at either side between the sphere and the tube. The effect lasts longer thus more impressive. I used it at work as an ice breaker. It became known as Andy's Magic Pole.

I think having a longer tube of copper would show more of a difference between falling speeds.

Totally cool!

Amazing!

Impressive 😁

As others have suggested, matching the diameter of the tube closer to the diameter of the magnet yields more impressive results. I like to use a steel ball and a ball magnet of the same sizes in the copper plumber's tube as a fun demonstration.

Thanks

This was so cool

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.

Never knew about this effect. Its really weird !! 🤯

"To remove the shell, I use my sandblaster." Look down on my piece of sandpaper in envy. That 'levitation effect' was very cool though.