PERMANENT MAGNET PROPULSION DOESN'T USE MUCH ELECTRICITY

        PERMANENT MAGNET PROPULSION DOESN'T USE MUCH ELECTRICITY


     I am once again working with permanent magnets since it may be some time before I would be able to build a nice model with electromagnets that rotates on a needle point axle/bearing.

     The advantage of permanent magnets is that they don't required very much electricity except for a motor to turn them. The motor uses very little electricity compared to a 30 to 70 watt electromagnet.

     So first let me show my device and then discuss it. Here it is:

     The red turning thing in the middle of the aluminum pan is a HexBug spider toy robot. I am using it as a remote controlled 360 degree servo. I have taped 14 0.5 inch diameter neodymium magnets to its rotating head as well as 94 grams of inexpensive clay (blue) to counter balance it. For it to work either it needs to be off center or the aluminum pan underneath needs to be out of balance.

    Again it works because the center of the magnetic torque from the magnet interacting with Earth's magnetic field is at a different point from the center of mass where the device will tend to turn at. Since they are not in the same place the device will rotate around a third point and one side of that point will have more mass than the other side so momentum or if you will centrifugal force will move the device in a line.

     Next we added an outer aluminum pan to rule out water current that might be generated as the device rotates a lot (Also this means it does not need to turn the whole craft to work) as seen below:

     In this model of my device the clay counter balance has been removed from the top of the HexBug and the magnet has been centered. To arrange for it to still work the clay square weights around the inner aluminum pan are unbalance with three spread out around 180 degrees of the circumference of the pan and one missing from the opposite side. The inner aluminum pan is connected to the outer one with a washer and a thumb tack both embedded in clay. The washer is on the bottom of the inner pan and the thumb tack is pointed up on the outer pan so the point goes into the hole in the washer. The inner pan is filled with just enough water for the link to work and the friction to be very small. The inner pan floats in the water in the outer pan. The outer pan is floating in the water tank (a plastic storage container with about 5 inches of water in it.)

    I have no doubt this is working. My issue is how could it be scaled up? Well I have a hunch that I will explore in a future post.

THREE COIL STATORLESS MOTOR ONE COIL OUT OF PHASE FIRST ATTEMPT

THREE COIL STATORLESS MOTOR ONE COIL OUT OF PHASE FIRST ATTEMPT

     In one attempt at electromagnetic propulsion for spacecraft I used a stator less motor on an axle mounted on a delicate needle bearing.

     Some time ago I built a stator less motor out of three spools of wire on a steel bolt. It was mounted on an axle and mostly built out of Lego parts but the axle had sewing needles at each end to reduce friction.

     A stator less motor is just a motor that uses Earth as its permanent magnet (stator). As the electromagnet is powered it turns on the axis like a compass and points north and south. Then the polarity is reversed, in my case by an Arduino with a Relay Shield or separate relays or even a motor controller, so that it continues to turn in a circle. It is a motor.

     Here is a similar model like the one I used in my electromagnetic propulsion experiment:

   This stator less motor uses a photo cell and light for the governor to reverse polarity. It has to be pointed so that the semicircular piece of card stock that blocks the light from reaching the photocell turns just so the polarity reverses when the electromagnets are pointing north and south.

     The actual model I used in the experiment was different in that the three coils were on separate controllers or relays so one on the end could be powered with it's polarity out of phase from the other two during half the cycle.

     The two in phase electromagnets keep the armature spinning. The out of phase coil on the end transfers the momentum of the spinning armature through the axle to push the little model in one direction in the water.

     This version of electromagnetic propulsion is very promising. My model needed a better version developed but did work. There were some setbacks due to the connections that I used to transfer the electricity to the armature and coils. I plan to make a better model of this in the not too distant future.

     At any rate below is a video of this version in action. It can be seen to move towards the left of the screen. It is placed on a piece of Styrofoam and floated in water away from any magnetic or metal objects.

Check my Youtube.com channel for more videos.

HOW THE ELECTROMAGNETIC THRUSTER WORKS

               HOW THE ELECTROMAGNETIC SPACECRAFT THRUSTER WORKS

     I have gotten to the point where I have a somewhat working model of an electromagnetic propulsion device that would work in low Earth orbit, at least in theory.

     It is easy to see how the magnet turns to align with Earth’s north and south magnetic poles just like a compass and than how an electromagnet by changing its polarity is made to rotate in a circle like a motor. We saw how adding a fin to push against the water made my model move in a line through the water. We have farther more seen that we can accomplish the translation from rotation to linear motion by placing a weight on our model.

     This may seem a little mysterious so what are the actual mechanics of an electromagnet rotating in Earth’s magnetic field like a motor translating to linear motion?

     I have given this a considerable amount of thought and I truly believe this is the easiest to grasp explanation I can currently provide:

     The torque from the electromagnet interacting with Earth’s magnetic field is applied at one point on the device. That is the force of rotation provided by the electromagnet.

     The device has a tendency to rotate around its center of mass, which is at a different point. I am not sure what physical law states that is so but it seems self evident.

     Since there are two points where rotation is ‘trying’ to take place the actual rotation occurs at a third point. Again this is a little intuitive but shouldn’t be hard to grasp.

     So when the device rotates around the third point, which is not the center of mass, the heavier or more massive portion of it moves in an arc. This is also intuitive since if the center of rotation is not at the center of mass one side or the other of that mass must be greater.

     That portion of the device with the more mass pulls the whole device with it as it rotates. This is from centrifugal force or you may want to think of it in terms of movement and momentum. (Physicists say there is really no such thing as centrifugal force, but that is beside the point.)

  

                                   MORE TO CONSIDER ON PRACTICALITY

     To use this as it now is in concept would require the spacecraft to mostly consist of the electromagnets and also that the whole spacecraft would need to rotate. Here the concept is only in its baby stages and might be developed to the point where it could rotate on an axle that would then be attached to the spacecraft.

     Also does the device only have the capacity to go in one direction? That is something to consider.
Actually I have some ideas on this some of which I have already tried out.

     The first way to control the direction of linear motion is to control the direction of rotation. The opposite direction of rotation will make it go in a different direction. Next the direction may be affected by changing the timing of the reversal of polarity of the electromagnets. I have done some experiments and this seems to be the case. Also, the position of the secondary electromagnets would alter the direction of linear rotation.
 
     Of course it can go in any direction along the plane parallel to the lines of Earth's Flux if it instead of rotating swings side to side like a pendulum.


Here is a diagram: