I guess the next step is to build a superconductor clutch to avoid the heat issues. That'll totally work.

The positioning of the weights at 7:44 is such a pleasing real-world representation of a log graph, I love it

The comparison shots of the falling weights was incredibly well done

Magnetic coupling is very useful for underwater applications, where you want to disconnect the propeller from the internal electronics. Back when I was in highschool, we built an autonomous underwater vehicle and faced a real problem with isolating the propeller's entrance.

I'm a physics professor and this whole project is incredible! That's one whole chapter of the textbook in a single short video!

The side by side comparisons are astonishing, it’s amazing to visualise the different behaviours induced by different configurations of magnets and weights

I was very dubious at the start, thinking, “oh, yeah, another magnets perpetual motion scam”. . . but no. I learned a lot from this. . . an honest presentation. Nobody’s going to win the Tour de France with this setup (especially me, a 79-year old time triallist)😊 Well done, sir!

That was a brilliant, thoroughly well-thought and very well executed way to find out something is a not such a good idea. The effort put into this is admirable!

As a bicycle mechanic over in Germany I gotta say, I really love your bike related videos. They give me great aspiration, sadly I lack the funding to copy your concepts for my own fun. But they make great talk in the break room!

Those calculations with the dropping weight videos were awesome, such an excellent visualization.that section was great!

I just discovered your channel and I love it! Your editing, your ideas, your explanations - incredibly well done! Thank you so much and this is so cool

"...and this result wasn't linear" @7:38 Beautiful visualization. Nicely Done!

As a retired engineer who cycles a lot, I enjoyed this immensely!

Tom again shows us not only how clever and creative he is, but also just how great UKposts can be with the right content providers!

I think - The reason why flipping the center magnet works better is the field gets conentrated closer to the disk. Also the eddy current created by the first pair runs opposite to the one the second pair creates. The checkered pattern may be creating less field near the disk. Nice idea and nice video!!!! Really enjoyed!

First video I've seen of yours and I really enjoyed. I like the way you're passionate but not loud! You stick to the subject whilst allowing small tangents and your explanations are totally understandable! Great work!

The alternating magnets for stronger eddy currents was a great idea! You might want to look into the Halbach Array (a specific way of alternating magnets) that makes the field strength even higher. I think it might perform better than only alternating the magnets.

Your meticulous research and trials of materials and forces is truly impressive. Then to advise us that it didn't work as you had hoped shows your humility. Thanks for sharing this whole story.

Very good job on your thorough research and impressive fabrication skills! You essentially created the opposite of a magnetic braking system like on the Telma system. I drove heavy vehicles with a Telma and they work really well but they generate a lot of heat so you had to mind how much they had been applied.

You are much more analytical than I. I like trial and error. That said, I do something similar using neodymium magnets mounted on disks. I machine my disks out of plastic cutting boards using a lathe. I mount magnets about the flat circumference of the disk, then use either live steam or compressed air to spin it through a pick-up coil to generate electricity. I arrange the 1/2" magnets all facing the same direction (for d.c.) or facing n-s-n (for a.c.). I use both piston as well as turbine homemade engines. I build windmill-driven air compressors as well as small air engines as a hobby. Great fun! Thanks for your VERY ENTERTAINING channel.

This channel was new to me. I was blown away by the concept, quality of the build, quality of the experimentation, and the quality of the video production. You, Sir, are really good at this!

Hi Tom The checkerboard is only useful if you also want drag in the left-right direction.; generally the magnet diameter should be greater than the gap between facing magnets. More importantly, please look into "back irons" - these will easily improve the effectiveness by 2x or 3x and shall also eliminate the problem of the chain sticking to the magnets :)

Every time you have some different ideas, we see it implemented within seconds in the video. As an engineer, I know the pain anxiety of the challenge to go through implementing ,and the excitement during the test, and of course the joy when the idea works.

The very healthy and honest conclusion at the end nailed it. I´m glad someone has done this, because it was entertaining and informative to watch. Good luck for the next one.

Hey that's pretty neat to learn about the alternating polarity creating a greater resistance. I didn't think of that. You could print a little cube grid that holds multiple magnets with opposing fields and probably get a much more impressive slow down when dropping it down a pipe.

I think you may have missed a trick. Putting an iron backing plate on both back sides of the magnets (ie facing opposite the copper disc) would give you two additional advantages. One being the flux would be more constrained and not grab the chain/spokes and the field facing the copper disc would be more intense. However the heat due to loss will definitely be more severe when the clutch starts slipping and will equally affect the magnets, which in your case, due to their size might have been a bit cooked too, but cooled faster due to less thermal mass. But in theory, the increase in efficiency would mean less slipping. Another factor is that neodymium magnets permanently lose their magnetism when heated to approximately 85deg C, which is why when these types of clutches are used in industrial applications, there is usually a significant liquid cooling system that either flows through the clutch components, or the clutch is immersed in it. They are very precise and consistent (repeatable) clutch designs that can absorb massive dynamic changes in force, so they are very useful in other applications, where longevity and smoothness are more important than efficiency in the force transfer. They are also used as brakes and dampers for similar reasons and also have more traditional lockup mechanisms and or clutches for greater efficiency when output (or input in the case of braking) has reached a certain speed. Obviously these are stupid expensive, mostly due to materials, proper matching of the specifications, and definitely being customised for the application, not to mention bulky, but sometimes they are worth it, to solve particularly difficult problems where traditional force coupling mechanisms don’t work as well. Anyway, sorry for being “that guy” at the party, great video and demonstration of a very useful and niche device!

I like how you're talking with simple language and not just scientific things so everyone could understand you Thanks man

Thank you. This is pretty amazing. So happy you did this!

It's always so mesmerizing to witness eddy currents. I was playing with magnets and a copper pipe a while back and it's so so interesting to see it happen. The clutch idea is interesting, I could see this being useful in some kind of application that may get sudden changes of resistance, and it would save the output shaft of the motor. Rollercoaster brakes also work similarly to this.

I think you calculated based on cruising power rather than the power needed to accelerate/decelerate. Really interesting build!

What an excellent video Mr. Stanton. Thank you for posting.

I'd love to see a return to this experiment with more designs and maybe some alterations with additional parts to see if this could be further built on as a viable drive method. The concept seems really awesome, and I'm sure there's got to be some utility in this somewhere.

In home exercise bikes, a magnetic brake is sometimes used in the form of a set of fixed permanent magnets (or electric magnets in expensive devices), and a perforated metal disk (similar to an aluminum alloy) that rotates through an upshift pedals. The adjustment of the braking force is regulated by changing the distance of the magnets from the rotating disc. Excess heat is dissipated from the disk into the air by means of a small impeller with blades on the disk shaft. Thus, it turns out to achieve a fairly wide range of loads (from 50 watts to 1.5 kW) with modest dimensions of the device.

Making the copper plate thicker would reduce the number of magnets needed by decreasing the resistance for the eddy currents. And as other people have commented mounting the magnets in a steel mount would also improve the performance by helping to concentrate the flux. Similar just for kicks project would be to try to convert this into a homopolar motor regenerative braking setup with some big capacitors.

Another brilliantly composed and explained video. Magnetism is a very strange beast.

I am speechless and you are a highly underrated engineer. I really loved the project.

Tom, I really like your focus on the subject of your videos. Been watching you for years and as many other channels over-hype, fast-cut, force jokes, etc... you've stayed one of my favorites. I can watch you when having a slight headache and it's not too much but rather interesting and calming. Also, good on you to commit to all your interesting ideas, figure out if something would work and show it. You test so many things a lot of people probably have wondered about but no one has seriously tried yet, let alone shown it to the world. Please keep being you, lovely to watch always!

What happens if you pedal backwards? Would that provide more braking force? How would the addition of an electrical current affect the resistance? Great videos! I really enjoy watching and learning such interesting concepts!

There is a bicycle trainer device called the Kinetic that has used this principle for decades. The resistance unit is hydraulic, that has a sealed chamber to prevent leaking. It’s hard to seal around a shaft, so they drive an impeller inside the sealed chamber with a magnetic clutch. My trainer is decades old still works great and no leaks.

I would love to see this project explored again, but with bike wheels that aren't spoked, but rigid body, like a 5-spoke carbon body wheel. You could also explore using a carbon or aluminum frame bike, and belt drive instead of chain drive, so you can eliminate the magnetic interference variables + reduce the weight of the bike.

Two points I'd have tested; 1. how much does it slow you if you pedal backwards? 2. what does it do for controlling speed when going down a hill (something steep enough to normally require braking)? Interesting as always! 👍👍

One factor you seem to have overlooked is that if you want higher braking at low speed you could always just pedal backwards and increase the effective relative speed of the wheel vs the magnets. I do otherwise agree with people's suggestions of reducing the amount of copper used. I'd also suggest, from my limited electrical engineering knowledge, that you cut air gaps between sections of the copper, as that should cause greater eddy currents since the air will act as a dilectric and theoretically cause increased resistance. Will admit I'm unsure if that'd improve the effective coupling overall, but it seems like something that would at least have an impact.

Thats one of the coolest projects ive seen on here! Great job.

Thanks, Tom. Brilliant experiment and execution. Keep them coming.

I am never more excited then when i see a video from Tom. The step by step research to prototype of an idea is unmatched in my opinion. Truly top notch content!

I noticed that this is much the same as the way my exercise bike works. There are two belt-and-pulley setups that spin an aluminium disc between a couple of magnets. The resistance is varied by moving the magnets in or out. And yes, my efforts go into making the disc get hot!

love it, based on the idea of the magnet casing i will try to make my exercise wheel that works with friction into a magnet brake one that hopefully is quieter

Absolutely brilliant!

Babe wake up, new Tom Stanton video

Even after 3 years of engineering school, I still learn so much from your channel. Great videos!

this type of break will also have an anti lock feature. as the rpm approaches zero the torque falls off as well

This is so cool. Totally impractical, but a great, fun eddy current demonstration with a few simple benchtop experiments to figure out the details.

You had an idea and you concisely show how you went about implementing it and the methods you use. Thank you Tom for inspiring the younglings, I have no doubt we'll get some amazing innovations in the future, influenced by your ability to educate. Even though I pay little attention to the numbers and equations I still end up feeling slightly smarter from watching your videos.

would be cool to see how pedalling backwards while moving forwards would effect the braking power.

I love your work man, your just awesome

That sprocket piece riding the chain was so funny to me 😂😂

You could try mounting the magnets as a halbach array, it's used to point most of the magnetic field in a single direction meaning you'd get more Eddy currents and less chain sticking!

I was familiar with this phenomenon from roller coaster brakes, but you explored far deeper than I had ever seen before. Fascinating video and good explanations.

This is a brilliant demonstration of how great ideas don't always pan out. I hope this video inspire a lot of viewers to consider engineering as a career.

The wasted energy turns into heat. Answers a lot of questions about eddy currents. Thank you Tom.

I have an idea for you mate. You could have a variable gearing effect by mounting the magnet cages attached to radially mounted springs. Mill slots in the disc around where the magnets sit under spring tension to reduce the eddy currents formed there. Use the centripedal acceleration to have them push outwards from centre and thus engage with the intact portion of disc on the perimeter at an RPM detemined by the spring rate. You'll have basically combined the centrifugal clutch with the magnetic drive.

In case you weren't aware, mag clutches do exist and are in wide use, up to around 20 horsepower I believe. Should be no issue for your uses. I miss the air engine videos.

Fantastic science project! Well done!

Fascinating. Thank you.

If you revisit this project, you should try a halbach array for the magnets. Should get you a much stronger field

Appreciate you Tom, the amount of time and effort put in to every video shows.

Very interesting design. I think some of the indoor training bikes use the same phenomenon to produce resistance.

well you had a lot of fun and learnt a lot too. A good source of strong magnets are old hard drives which every one has a stock of in their shed . I'm using some to hold a gate open and to stop it slamming in the wind using a copper -magnet damping disk (well its in progress)... cheers

You always have the most interesting bike technology builds. Your anti-lock brakes from a while back inspired me to design my own and I love the way they work

Halbach array would give you even more magnetic force per magnet given to the field direction you want. Of course you would simply heat your disc faster, so there's that. This is a super interesting concept though, for sure! You could also have direct magnetic interlock with a squirrel cage style ferro-magnetic core, like how induction motors work. I like the idea of creating a 0 friction gap in the drivetrain.

This is amazing. I am enjoying this so much!!

Wow, this is a really great experiment. Thanks for sharing 👋

12:19 “still able to oop”

Great work! I think this is essentially an induction motor. What helps the induction motor work more efficiently will help this clutch as well, e.g. adding slots to the disk to limit the directions of Eddy current, adding iron cores into the slots to increase the magnetic flux density (B = muH)

Ive always wanted to do something vaguely like this - have the pedals turn a generator and a motor turn the wheels (potentially having one on each wheel). Youve essentially combined the two sets of windings into one and eliminated the conductor between them. I was wondering how much energy that disk was soaking up. Good thing its copper!

Cool idea and nice mapping of the theory into the engineering of the parts

Great video, with brilliant visual comparisons. A few options to make life easier: 1. Use a disk hub (machined mount ready to use. 2. For mag interference with chain...Use belt drive instead of chain... they are superior in some ways and used by touring cyclists.. 3. For spoke mag interferrence, "string" spokes are already succesfully used

The shot at 7:41 showing the effect of different magnet amounts was amazing. I bet it lines up with it's plotted graph.

the heating up of the copper plate reminded me of KERS (Kinetic Energy Regeneration System) systems in electric vehicles. EV's make use of that principle to regain the energy for the battery that would have otherwise been lost to heat when slowing down.

Cool experiment. i love when people still show "failed" products. great learning experience for everyone and isn't really a failure but a collective learning experience instead.

Watched a number of your videos. So nice to see someone who truly understands engineering, can explain it well and actually make some impressive things. Keep up the good work!

Just be careful of road man holes lifting up to stick with the magnet matrix

Nice bit of work! I would imagine that the heat created in the disk would also be created in the magnets, so the plastic magnet housing will soon loose strength. This scheme would make a nice water heater driven by a windmill. Wrap copper pipe around the static magnets to cool them, and using a pair of rotating copper disks with water bled between them via a gland on the shaft to cool the disks. Could be a nice build! Thanks.

THATS what the world needs ! Engineers with energy and courage! very well done , maybe try an hydraulic torqueconverter next....

I love how you had an idea and made it reality to test it. That's the sort of real-world findings that could prove to be useful for all kinds of applications that may even be totally unrelated to your project. I bet someone out there will see this and get inspired to try this in something else

Amazing idea! You can also separate copper segments into angles. This way the current must go in and out of radius. Your coupling will be much much greater! You can also drill lots of holes in the copper plate.

Regardless of the final result, this is still an interesting project and informative video. Nice work.

It would be cool to see this applied in an automotive application, such as replacing the fluid coupling of a torque converter in an automatic transmission, or in a rear differential housing as a sort of limited slip differential.

This is cool. If you decide to revisit this idea, I suggest you use a one-way clutch bearing for freewheeling and also add a U shaped back-irons for the magnets. This helps steer the fields in a shorter path and should increase the flux (IIRC) in the gap on the copper disc while reducing the magnetic forces on the chain and forks. Soft iron is best however plain steel should be fine as the magnetic field in the magnets are 'static'.

A halbach array instead of a simple N-S magnet setup would would make the effect stronger for the same size/number of magnets. Besides, that, pretty cool!

That's the coolest over engineered non functional piece of bike tech I've ever seen. That was really cool.

Thanks! Nice video with conscience breakdown of disadvantages of this project. I do learn a lot from this video.

Fantastic project! Thank you for going through the trouble of recording the entire development process and sharing it with the world!

Really like how you put the different tests with different variables are shown alongsude each other in real time. It really helps visualise the relationship between the variables, like a real life graph. 👏👏

Clever lad, thanks for sharing this experiment.....

really interesting and well put together, cheers

You have to admire Tom's enthusiasm, he had an idea and he set about trying to bring it to fruition. Not all experiments work , but I am sure this attempt has brought him some useful insights of what he might try next.

Audio glitching in the clip @12:11

You could probably play with the disc design and cut windows into it. This would potentially give you move controlled eddy currents. Another idea is the make the magnetic rotor smaller and offset the rotors axis relative to the stator. This allows the rotor to act as a magnetic gear.

Absolutely fascinating Tom! Well done Mate!