MagneticPropulsion

Compass Boats propelled by Earth's ambient magnetic field with moving parts... Stay tuned:)

This still works even with a hemisphere boat. When the magnet is turned in the still boat it makes the boat turn and also move north. That is the underlying effect that makes magnetic propulsion work. Stay tuned:) #experiment #magnet #physics #acrylic

Uh Oh! In a hemisphere shaped acrylic boat the magnetic/compass propulsion experiment didn't work! Why? Is the whole thing a dead end? Not so fast. There's a perfectly good explanation. Stay tuned:) #experiment #magnet #satellite #thruster #physics

Centripetal Acceleration is equal to tangential velocity squared divided by radius. We calculated that for the 5 inch diameter motor armature at 100 RPM the centripetal acceleration would be about 7 m/s^2 or 0.7 g's. We calibrated the accelerometer and 8x8 LED matrix to light almost all the LEDS at 1 gravity so at about 100 RPM there should be about 6 and a half rows of LEDS lit up. So the idea is at some point in the future to integrate just the accelerometer into the motor control that is on the bottom of the armature and have it regulate the motor so that it could sense when the motor was going out of phase and make corrections or at least stop and restart the motor from a slow speed. Stay tuned:) #arduino #accelerometer #physics #experiment #magnet #motor

A little diversion with a nice project that will keep me entertained hopefully for over a year to see how long the battery lasts. You can paint the inner globe and it will look very nice. Much more fun than buying it and only a small fraction of the price for a Do It Yourself project. Stay tuned:) #diy #experiment #magnet #compass #motor #physics #inventions #science

We recently saw the MOVA globes reviewed on Veritasium so watched it's inventor's videos on how he invented it then searched some more and found the recommended video below on how to make your own for only a few dollars. It uses a clock mechanism that you can buy in any craft store for about $10 that will run on a AA battery (instead of solar cells) for 1 to 2 years and maybe longer. This was our first attempt so it's not absolutely beautiful but has a real nice effect. We had trouble finding the right size balloons. You need 12 inch round balloons. Our balloons were smaller or not round and only covered enough of the inner 3 inch acrylic sphere to keep it water tight but not to look perfect. We think of it as a 1RPM compass motor. Recommended: "Perpetual Motion" rotating globe (Part 2) https://youtu.be/-6UFjmIurcQ rotating globes https://youtu.be/CwBFaO4Lrgo MOVA origins https://youtu.be/EEJtHyv2Rqo Stay tuned:)

When the magnet/compass is away from the center of the balanced boat the boat translates a great deal more as it turns from east to north. Stay tuned:)

The actual physics is much more complicated since you would need to sum the x and y components of the force vectors as they interacted and decreased when the magnet turns to align north but the end result is pretty close to the experiment taking into account the resistance from the water and the difficulty in releasing the boat without pushing it. Something next to consider is what happens when the magnet is far from the center of the boat with a balance weight on the opposite side of the boat. That seems to be much more powerful. Stay tuned:)

Compass torque exponentially stronger than attraction. Stay tuned:)

Great kit! After soldering it together you can put it almost practical use as a toy. Great practice for SMD beginners. Stay tuned:)

This acrylic armature was built differently. The axle was put through the two discs. When the glue cured the middle was then cut out. In this way the axle on top and bottom lined up nicely. There are some other factors that cause wobbling but the motor runs much better and turns as fast as the N20 motor can turn it. Stay tuned:)

Was all set to make a new armature but then thought of balancing this one better and it made a big difference. 180+ RPM! Still has a lot of wobble though. Stay tuned:)

The armature is not reduced in mass to only 300 grams. The approximate torque of the 20 magnets interacting with Earth's magnetic field is 1.4 millinewton meters. According to my math it should accelerate to 170 RPM in 10 seconds discounting friction. Of course there is friction and also the armature is not as straight as it was hoped. Next one will be better:) Stay tuned:)

A force couple is when two equal forces in opposite directions are separated by a distance. The resulting torque is one of the forces multiplied by the distance. But the key thing is that a couple can only result in torque to make a body rotate around its center of mass no matter where on the body the force couple is. So In this video a best theory is explained as to why the boat accelerates from only the forces of the compass. Stay tuned:)

By using a set of mending plates to hold the two north ends and two south ends of the two stacks of magnets close together we are now able to fit 20 magnets into the acrylic armature of the Earth field permanent magnet statorless motor. It now can go 160 RPM. Stay tuned:)

The magnets make the boat turn near the center of the magnets. The boat does not turn at its Center of Mass. A reaction wheel can only make the boat turn at its Center of Mass. This has to do with angular and linear momentum and the behavior of rotating objects and colliding rotating objects. Yet it is a very simple experiment that even a child can do. It has very far reaching implications. Stay tuned:)

The motion is much smoother because the magnets and servo have been moved a little forward from the center of the boat. Now with 10 N52 3/4 dia by 1/4 in magnets and more weight added to the back of the boat it goes pretty fast possibly to and inch in 4-5 seconds at its fastest. So maybe it's just as fast as the same 6 inch plastic boat with 12 magnets that it started with. Also the servo moves are now 60 degrees so it goes 2 moves on one side then 2 moves on the other side. Stay tuned:)

As the boat approaches the North end of the water tank it's speed is about 16 inches per minute. By sticking the like poles of the magnets to mending plates more magnets are able to occupy less area. Stay tuned:)

Adding 4 more N52 neo magnets to the motor increases its power significantly. It is able to self start and run almost 40 RPM faster than before. Of course without an friction it would run as fast as the motor could turn... Stay tuned:)

Cats are able to land on their feet when dropped upside down by a maneuver known as "cat-turning" which involves a turn and fold of the cat's front and back body. Here it is simulated with two servos just to illustrate the point that angular velocity can change by an object changing its shape and no external torque applied to it. If the maneuver were repeated over and over the boat would continue to turn. This also can be done with a counter rotating weight but the two servos seem to drive the point home that there is motion (at least rotation) without any force (actually torque). What if an already rotating object changed its shape? Could it change its linear velocity? It's very hard to find an authoritative discussion of the matter. Stay tuned:)

As stated in the video the magnet rotates around it's center and not the center of the boat's mass. A second reason for this concept working is that the magnet as a compass imparts angular momentum into the boat from an external source, namely it's interaction with Earth's magnetic field. Stay tuned:)

Fun kit! Stay tuned:)

Of course the subject of Stick Slip Effect will come up with this kicker boat but it is argued that Stick Slip Effect is not the main cause of its linear motion. Rather, the momentum from the compass is added to the boat and the kicker translates that momentum from angular to linear. In other words this should also work in a friction less environment. The speed is seen to average almost 8 inches per minute so at some points much faster than that. Stay tuned:)

It turns pretty quickly for a boat by the compass power of bigger magnets. Water current created by the boat rotating interferes somewhat with the demonstration. When the kicker servo moves a weight away from the center of the rotating boat there's no push but when it draws the weight back in it moves the boat. Stay tuned:)

The powerful magnets form a compass with about 2 millinewton meters of torque in Earth's magnetic field. A small electric motor turns the magnets so they are not pointing north. The magnets keep trying to point north and the electric motor keeps turning them so the acrylic armature, free to rotate, turns under the torque of the magnets against Earth's magnetic field. The motor is shown running as fast as it can run. Stay tuned:)