Electronic Levitron...How the heck does this thing work?

[Lakes]

Yup, I seen that (suspension) video and also the point contact (usually a lead pencil against a mirror) type using ring magnets.

If this is the type used from the above pictures, they were not clear enough for me to tell.

I`ll have to watch the electrostatic one though, not sure if I've seen that one.

Much more interested in your attempts at a "no-contact" type of levitation, but I am beginning to see how it works with the circle of permanent magnets as stabilizers.

Once that is working the next step would be to inductively light some LEDs as well.

[TinselKoala]

There is "no contact" in my coil-on-top maglev system and also no stabilizing magnet underneath. It's all done with optically-sensing the shadow of the bottom of the object and switching the coil on and off by the Arduino driving a power mosfet. The program in the Arduino corrects for ambient light by turning off the illuminating LED briefly every 100 pulses and sampling the ambient light falling on the photosensor, then correcting the pulse timing and strength so that the levitated object stays in the same position regardless of room lighting changes.

The system described by AC where the major lifting is done by PMs and then the coil just modulates that field, is a patented system that uses very little power, and also has the advantage of not dropping the object when the power goes off, instead the object jumps up and sticks to the PM lifting the weight. Sorry, I don't recall the inventor or patent number but it's available as a commercial display system as well. I think the electronic Levitron that is the subject here is also using that system, but inverted, acting in repulsion instead of attraction. Whether the field is sensed by Hall sensors, or the position sensed by optical means, is a question that is separate from how the levitation and stabilization is actually performed. Each sensing system has its advantages and disadvantages. I think a Hall effect sensing system will turn out to be more accurate and robust against outside perturbation, but also more difficult to implement in the actual build.

Still waiting for my Hall sensors from China, probably won't be here for another week at least.

Somebody (Lidmotor?) has demonstrated a top-coil levitation system that rotates the object and also lights up an LED inductively. I can't find the video at the moment, maybe someone else can. I did get an LED to glow a bit while being levitated in my system but not as well as Lidmotor (?) did in his.

[Lakes]

The "coil on the bottom" system is more visually impressive, but of course more difficult to achieve.

I have seen a video where the "coil above system" is used to suspend a beer bottle and rotate it for an advertising display.

I will patently await the results of yours (and/or others) efforts for the "bottom coil" system.

[allcanadian]

@TK
I thought about patenting my magnetic bearing as I have never seen one like it however it would be better served in the public forum... so here it is.


Take two magnets in attraction and slip a 1mm plastic shim between them, mine are N42 150 lb pull strength ring magnets. Now try to pull them apart, we cannot it's too hard so we must slide them apart pushing on one and pulling on the other. I was doing this when I thought Hmm...shear force?, why not have four magnets with a shaft in between the two inner magnets and a frame holding the two outer magnets attracted to the two inner magnets apart.


Frame--NS   NS--shaft--NS   NS--Frame


Now imagine the left hand side magnets pull 150 lb to the left and the right hand magnets pull 150 lb to the right thus the shaft in the middle is in perfect magnetic balance pulling neither left nor right when perfectly centered with equal gaps on both sides. The frame must be strong and rigid because the frame magnets are pulling with a force of 300 lb+ inward just as the shaft magnets are also pulling with a proportional force outward. The adjustment bolts are to set the 1mm gaps between the end magnets in attraction and to adjust for the fact the boards keep warping under the strain, lol.


The neat part is that the attractive magnetic forces are axial however the load acts radially downward, the load is carried by the magnetic shear force on the magnetic field between the magnet pairs on each end . I use a 5mm ball bearing on one end to stabilize the gaps and the axial load on the 5mm bearing is measured in grams while the radial load peaks at around 40 Kg on the bearing shown. Which raised a question in my mind, the pull force between the two magnet pairs can have literally any value (tons)while the magnetic shear force carries the load however if both attractive forces sum perfectly to zero then the axial load would still be in grams thus it is easy to see why the system is 99% passive.


In a perfect world the magnet gaps on each end of the load bearing shaft would be perfectly equal and the axial forces would sum perfectly to zero thus the axial load on the stabilizing bearing(s) would be near zero and the magnetic shear forces would carry 100% of the load.


I believe the idea really clicked while reading A.D. Moore's book on electrostatics at the time. That is a cube of aluminum the size of a sugar cube in which all the charges have been separated by a distance of 1 m will have an attractive force of 32 million million million pounds... and yet all of these forces somehow sum to zero in this little cube of aluminum. If that does not boggle the mind then I submit nothing will, lol.


It's yours use it.


AC

[TinselKoala]

I hate to burst your bubble, AC... but your system, if I am reading it right, is exactly the "Mendocino Motor" levitation system, also used by Steorn in the vertical plinth Orbos and also used by me in the video of the ES powered motor above.  I don't think you'll be able to patent it...

Steorn used powerful ring magnets, two on the shaft and two in the frame, and a hard ball bearing against a micrometer head for axial support and adjustment. This allows vertical shafting or other orientations. The Mendocino Motor design appears in certain magnetic desk toys (without the motor part) and also in many YT video demonstrations of motors, usually solar-powered with magnets and coils in addition to the opposing support magnets (rings on shaft, other shapes possible on frame), but always with the single point contact restricting axial motion. The usual design, as I've shown in the ES motor, only works horizontally because gravity provides the stabilizing force up and down. Concentric ring magnets as Steorn used mean that the magnets themselves handle all stabilization at right angles to the shaft.

In CLaNZeR's replication of the Steorn Orbo plinth, you can clearly see how the ring magnets are arranged, to produce forces in opposition just as you have described. The rotor/shaft assy is pushed _up_  gently against the axial adjustment screw and all the weight is supported by the magnets in repulsion. And the strength of the forces and the precision required is why I can't at present duplicate this system, my necessary tools are not available to me (they are in Ontario and I'm in Texas). Although I do have a set of the correct magnets, donated to me some time ago by a Steorn replicator from another forum.

BTW congrats on reading Moore's book. Not too many people know about his work. I guess you've seen my Dirod and some of the demos I've done with it.