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Author Topic: This is why my magnet motor projects doesn't work  (Read 7944 times)

Low-Q

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This is why my magnet motor projects doesn't work
« on: May 31, 2017, 01:25:47 PM »
Hello all,


I have used simulators to test ideas. FEMM is frequently used. In cases where I have been "convinced" that a project is worth building, I always end up with a non working machine.
Whe I simulate a rotor magnet, I have always looked at the torque. This is not a good way of simulating motors. The poles in a regular electric motor achieve torque to the shaft because the rotor poles add torque through their own axix. Its like unbolting nuts on a wheel when you change tyres on a car. The wrench adds torque around the hub while torque is applied to the nut that is off center. The poles in an electric motor works the same way.


So, if you want to design a magnet motor, you must lock the poles in the same angle regardless of where it is in the cycle in order to change from attraction to repulsion. But this locking takes away the torque that is suppose to turn the shaft/rotor.
If you look at the forces in FEMM, not torque, and calculate the vectorized force based on angles in small steps, you will end up in zero, even if the torque readings from the same design shows a clear undoubtable torque in the same direction all around the cycle.


If you don't understand what I mean, you are welcome to ask.


Vidar

Doug1

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Re: This is why my magnet motor projects doesn't work
« Reply #1 on: May 31, 2017, 02:08:22 PM »
Which classification of motor?

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #2 on: May 31, 2017, 02:52:32 PM »
Which classification of motor?
The hypothetical permanent magnet motor (with no supplied electricity).
To make these work, the polarity must swap at the right timing. This cost energy.
If you imagine you have one rotor magnet and one arched stator magnet (like the one in brushed electric motors). The rotor magnet is possible to turn around its own axis. To this rotor magnet you attach a long rod (so it looks like a steam engine).
The rods task is to keep the rotormagnet pointing its magnetic field in the same direction all the time.
The rotor magnet will with this rod face the stator magnet with different poles at the entrance and the exit, making it possible to attract and repell at the right spot as it moves along the arched stator magnet. This happens to be true if we simulate torque. But remember where the torque comes from. There is no way of simulating a fixed position that gains torque in a system, so therfor the simulated torque readings is wrong.


I might be a little unclear here - I try to work at the same time I write this :-))


Vidar


Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #3 on: May 31, 2017, 04:32:34 PM »
Here is a drawing.


Position 1 -7 is the same magnet but in different positions. The magnetic field is pointing in the same direction all the time.

Doug1

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Re: This is why my magnet motor projects doesn't work
« Reply #4 on: June 03, 2017, 07:07:36 PM »
 Your thinking the magnetic field is going to work the same way a water wheel works when water flows by gravity over the wheel to push the paddles or buckets. The magnetic field doesnt flow like that. what is termed polarization is just a term used by people. What passes for North and south is just in relation to the earths fields so a compass can be used for navigation and people can communicate a location or direction to one another. It could just as easily have been flip flopped. The graphic images used to define a magnetic field are only relevant words of description for a particular conversation. They only really seem to expand and contact no wind like effect in the terms your thinking by your drawing. There is just as much pull back after the disc passes the apex of the field south to north north to south and each against it's own sign. Your going to end up chasing the mono pole which would make the magnet not a magnet. If you try to chase the neutral field of non polarized material that is still a pole just that is a neutral pole attracted to any pole different from itself. A permanent magnets field is established, it can only be distorted or destroyed. To squeeze one magnet past another under repulsion of fields has the same push back before and after and then will certainly get stuck in attraction as it is pulled back once it passes the apex of the field it is attracted to.

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #5 on: June 03, 2017, 08:41:45 PM »

Hello Dough1,
I know all that😊


My point wasn't to display a working magnetmotor, but to display why magnets can't do work. The drawing was just an example of an idea how to make them do work, but I fully understand that it will never work.
Permanentmagnets are conservative. They don't provide energy to the surrounding, just a passive magnetic field.


I am soon finising a project like the drawing above. This project will cast light on what people doesn't seam to grasp. Namely why permanentmagnet motors can't work.


In this thread, I have no intension to claim that these motors will work, but post a proof about why they CAN'T work ;-). So people don't need to wonder if it is worth building big expenseve projects that will never work.


Just as an attempt to help people here to not waste time on permanentmagnet motors.


Vidar

Your thinking the magnetic field is going to work the same way a water wheel works when water flows by gravity over the wheel to push the paddles or buckets. The magnetic field doesnt flow like that. what is termed polarization is just a term used by people. What passes for North and south is just in relation to the earths fields so a compass can be used for navigation and people can communicate a location or direction to one another. It could just as easily have been flip flopped. The graphic images used to define a magnetic field are only relevant words of description for a particular conversation. They only really seem3 to expand and contact no wind like effect in the terms your thinking by your drawing. There is just as much pull back after the disc passes the apex of the field south to north north to south and each against it's own sign. Your going to end up chasing the mono pole which would make the magnet not a magnet. If you try to chase the neutral field of non polarized material that is still a pole just that is a neutral pole attracted to any pole different from itself. A permanent magnets field is established, it can only be distorted or destroyed. To squeeze one magnet past another under repulsion of fields has the same push back before and after and then will certainly get stuck in attraction as it is pulled back once it passes the apex of the field it is attracted to.

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #6 on: June 03, 2017, 09:02:42 PM »
Oops!!! That was a large picture. I sent the picture from my phone.
Couldn't make it smaller on the phone...

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #7 on: June 03, 2017, 09:55:34 PM »
A better "picture" from SketchUp

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #8 on: June 03, 2017, 11:44:01 PM »
I will hotglue a long carbon rod on the top of the upper knob over the rotormagnet. The knob is connected to the rotormagnet through a ballbearing. The rod will be attached to a piece that can glide in a track. The complete system will remind you of a steam engine - except there is no steam heat or water.
The long rod will keep the orientation of the rotormagnet stable within a few degrees.


The system is already tested as I let the stator spin and the rotor fixed. If I by hand keep the magnet orientated with the rotation of the stator (black ring where one half is opposite polarisation of the other half), there is positive torque at all places in the complete cycle. I did not expect this, but it makes sense now.


This experiment is done with the hand involved, where the stator is spinning instead of the rotor. Therefor I orintated the magnet by hand to keep it polarized in the same direction relative to the turning stator. So from the stators point of view, the rotormagnet is fixed in one direction throughout the cycle as it makes its cycle.
The interesting part is how our brain falsly think that this experiment will work if we let the carbon rod do the same job as my hand - keepeng the magnet orientated the same direction in space while the stator is fixed and the rotor is spinning as it is finally supposed to.


It should appear to be the same deal, right? But it's not - I think. Even if the relationship between the rotor and stator is apparently the very same.


I will continue this on monday. Now I am visiting my parents in law with my wife and kids untill sunday evening, Norwegian time.


I'll post a video of both experiments on monday or tuesday.


Untill then, have a nice weekend 😊


Vidar.

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #9 on: June 04, 2017, 03:04:23 PM »
I couldn't keep away from pen and paper. I just figured out a simpler way to keep the stator magnets in same direction.
I will also remind you that this experiment is not suppose to work. Its just for demonstration - and some fun.


Drawn 4 rotormagnets to show the concept of fixed polarization.
Guide rotor X is keeping the rotormagnets in correct direction.
The rotor magnets is attached to the main rotor Y.
A and B is the direction the rotormagnets wants to go. The torque from these balance out.
1 and 2 is the direction the rotor assumingly will go.


The large ring is the statormagnet. South pointing towards center on the left side. Opposite on the right side.

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #10 on: June 04, 2017, 10:02:34 PM »
Now I connected a long rod to the rotormagnet.
Let me describe the problem before I make a video.


Use the drawing above as reference.
To keep the rotormagnet in the same direction during the cycle,
they must be forced in the opposite direction of the rotors
desired rotation. This applied torque will therefor countertorque the rotor.
Say the rotor is suppose to go clockwise.
Then there must be applied a counterclockwise
torque to the rotormagnet to keep it in position.
This will balance the two forces, and the rotor will
not run.


However, if the rotor is stationary and the stator is
rotating, the stator will go counter clockwise
if I align the rotormagnet by hand - by turning it around
with the rotatong stator.


If you guys ever find a way to eliminate the countertorque
From the rotormagnet, you got yourself a running permanent
magnet motor :-)
I doubt it's possible, but if you manage to do this, the history-
books must be rewritten...


Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #11 on: June 04, 2017, 11:21:35 PM »
Tomorrow I will build a new one. Similar to the one in the drawing.
I can see now that the countertorque from holding the
magnets in right orientation as shown in that drawing,
appears to be taken care of already.
I suddenly got confused, so to analyze this in detail, I need hands on experience.


Vidar

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #12 on: June 05, 2017, 04:13:22 PM »
https://youtu.be/qLA4yQIpG3o


Here is a video. Maybe you understand better what I have been trying to explain.


Vidar

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #13 on: June 05, 2017, 11:32:09 PM »
Printing out new parts.
Stator will have 20 pcs 25mm x 6mm neos.
The rotor was printed in one piece including the magnet compartments.
One broke because the first printed layer merged it with the main rotor. Got to print that one piece separately.
The stator is finished in 1 hour from now.
Then, tomorrow I continue with the other parts.
Then I assamble all parts, and see what happens.
Probably nothing will happen. It always doesn't.


Vidar

Low-Q

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Re: This is why my magnet motor projects doesn't work
« Reply #14 on: June 06, 2017, 10:51:40 PM »
Almost finished. Did a quick test, but the neos are very very strong so it is impossible to demonstrate without damaging the relatively fragile parts.
I will first remove the rotormagnets which is 4pcs 25mmX6mm on each of the two arms
No magnets on the other two yet.
Then make an adapter so I can use a small stack of 10mmX2mm magnets instead.
Some photos :-)
To be continued.


Vidar