Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding

User Menu

Custom Search

Author Topic: Magnetic flux control idea  (Read 21441 times)

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #15 on: December 12, 2018, 07:08:04 PM »
The first obstacle I can think of is similar to the problem with the buoyancywheel in the video (First post).
Since the rods is angled relative to the wheels, one side of them (rear side relative to desired rotation), is more exposed than the other.
However if this is the case, the rods should have torque around its own axis that is going in the same direction as what I want the wheels to do. These forces probably cancles out.


The second obstacle is the ferrofluid under magnetic impact. What happens with the ferrofluid close to a magnet, is that it gets "harder" for objects to enter. The pressure in the fluid increase.
However, the narrow part has very little solids to enter, and more solid to exit at the wider part. Meaning that the buoyancy is greater at the wide side.


The third obstacle is a result of the first and second obstacle. Between the wheels, there is more surface area in front of the rods than behind them. The pressure from the ferrofluids impact with magnetism will push them backwards at the bottom. This will probably be counterforced by buoyancy differences in the second obstacle and the magnetic attraction from the narrow side.
However, if the rods weren't magnetic, it would not be attraction from the magnet, but the pressure caused by the magnet at the bottom would still be there and pushed the rods backwards.


In sum, these three obstacle is something I have been thinking of, and I assume none of them have any driving force in one or the other direction. What I got left is the difference exposed rods outside the wheels - at the narrow side versus the wide side.


Therefor I got to build it to see what is actually going on. Energy MUST somehow be conserved, right? What if it's not? ::)


Vidar




Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #16 on: December 12, 2018, 08:09:26 PM »
Three out of six rods isn't magnetic :'(
https://youtu.be/mtvHW5fj3Jk

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #17 on: December 13, 2018, 07:46:48 AM »
I have decided to cut the three "working" rods in half. They are too long anyways.
Here is more pictures.
I am printing out a bellow in flexible material to seal the space between the wheels.
Then I put ferrofluid inside.


Vidar

F6FLT

  • Sr. Member
  • ****
  • Posts: 394
Re: Magnetic flux control idea
« Reply #18 on: December 13, 2018, 11:47:32 AM »
Hi there. I haven't claimed anything. I just need to figure out how magnetism "works" on this. I know just as well as everyone else, that overunity or perpetual motion can't work.
This time I got stuck. I do not know what is happening to the device. I don't know what mechanism that counterforce the rotation, except friction. For me, as I write, I have no good reasons to why it doesn't work. I want to find that reason. To do that, I must build, because I can't simulate this.

Vidar

Hi Vidar,

You are in a respectable process that I am not criticizing at all. Unfortunately, it is clear to me that the underlying physics that you are missing will prevent you from succeeding.
Sorry to sound really pretentious, but if you see a child trying to make a jigsaw puzzle, and either you know there are missing pieces or he has mixed them from other puzzles, you know he can't succeed, wouldn't you tell him?
I'm not negative, I'm positive: you do a work of remarkable competence in mechanics but not in the right direction.

The movement of permanent magnets is a matter of magnetic potential energy, as weights under the influence of gravitational potential energy. Magnets move to the region of least potential energy.
The force on them is conservative, this means that the work between two points does not depend on the path but only on the potentials of the start and end points.
For the magnets to move, there must be a magnetic potential difference between the starting point and the end point. In a cycle, the starting point is the same as the arrival point, there is no potential difference, so there is no cause for magnets to move between the two points even though they have to go through a lower or higher potential point between the two. A ferrofluid doesn't change anything, it's also submitted to this principle of magnetic potentials.

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #19 on: December 13, 2018, 12:47:43 PM »
Hi Vidar,

You are in a respectable process that I am not criticizing at all. Unfortunately, it is clear to me that the underlying physics that you are missing will prevent you from succeeding.
Sorry to sound really pretentious, but if you see a child trying to make a jigsaw puzzle, and either you know there are missing pieces or he has mixed them from other puzzles, you know he can't succeed, wouldn't you tell him?
I'm not negative, I'm positive: you do a work of remarkable competence in mechanics but not in the right direction.

The movement of permanent magnets is a matter of magnetic potential energy, as weights under the influence of gravitational potential energy. Magnets move to the region of least potential energy.
The force on them is conservative, this means that the work between two points does not depend on the path but only on the potentials of the start and end points.
For the magnets to move, there must be a magnetic potential difference between the starting point and the end point. In a cycle, the starting point is the same as the arrival point, there is no potential difference, so there is no cause for magnets to move between the two points even though they have to go through a lower or higher potential point between the two. A ferrofluid doesn't change anything, it's also submitted to this principle of magnetic potentials.


Thanks for your input. The missing physics is the very reason why I want to build this. I already know it wont work, but I need to know why. Practical experiments never lie, and is the best way to learn the truth ;)


Vidar

citfta

  • Hero Member
  • *****
  • Posts: 1050
Re: Magnetic flux control idea
« Reply #20 on: December 13, 2018, 03:25:18 PM »
Hi Vidar,

You are proposing an interesting experiment.  I am familiar with someone who built a bouyancy wheel like you posted at first.  He built a much smaller version and did quite a bit of analysis on it.  It was too small to turn under its own power but a test he did showed something interesting.  He used a small DC motor to drive the wheel in one direction and turned the current down until the wheel would stop.  He recorded the minimum amount of current required to keep the wheel turning.  He then did the same thing turning the wheel the opposite direction.  He found that it required quite a bit more current to keep the wheel turning against the direction you would expect it to go if it could power itself.  He and several of us were convinced that a much larger wheel would probably turn under its own power.  But the complications of building it larger got the project put on the back burner I think. 



To test your device you might also try driving it one way and then the other.  The only problem with that is you need to make sure your motor draws the same amount of current in both directions when loaded the same.  I have worked with motors for many years and some are more efficient one way than the other.  Or you could drive the wheel on one side and then drive it from the other side to keep the motor turning the same way both times.



There are several areas of that design that can add a lot of friction to the free turning of the wheel.  I am afraid you will also run in to some of those areas.  One improvement you have made is the idea of using a bellows between the wheels.  If I recall correctly he had a solid box around the wheels with seals where the wheels met the box.  He said those seals were contributing a lot of drag.

The other area of drag was the friction caused by the tubes sliding in and out of the wheels.  I don't know anything about the ferrofluid.  Is it slippery like a lubricant?  That might help reduce the friction in this area.


Good luck,
Carroll

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Magnetic flux control idea
« Reply #21 on: December 13, 2018, 03:35:35 PM »
Hi Vidar,

You are proposing an interesting experiment.  I am familiar with someone who built a bouyancy wheel like you posted at first.  He built a much smaller version and did quite a bit of analysis on it.  It was too small to turn under its own power but a test he did showed something interesting.  He used a small DC motor to drive the wheel in one direction and turned the current down until the wheel would stop.  He recorded the minimum amount of current required to keep the wheel turning.  He then did the same thing turning the wheel the opposite direction.  He found that it required quite a bit more current to keep the wheel turning against the direction you would expect it to go if it could power itself.  He and several of us were convinced that a much larger wheel would probably turn under its own power.  But the complications of building it larger got the project put on the back burner I think.



To test your device you might also try driving it one way and then the other.  The only problem with that is you need to make sure your motor draws the same amount of current in both directions when loaded the same.  I have worked with motors for many years and some are more efficient one way than the other.  Or you could drive the wheel on one side and then drive it from the other side to keep the motor turning the same way both times.



There are several areas of that design that can add a lot of friction to the free turning of the wheel.  I am afraid you will also run in to some of those areas.  One improvement you have made is the idea of using a bellows between the wheels.  If I recall correctly he had a solid box around the wheels with seals where the wheels met the box.  He said those seals were contributing a lot of drag.

The other area of drag was the friction caused by the tubes sliding in and out of the wheels.  I don't know anything about the ferrofluid.  Is it slippery like a lubricant?  That might help reduce the friction in this area.


Good luck,
Carroll

It was more a case of working out why it would not work.

One thing low-Q needs to take into consideration is that the ferro fluid will also become magnetic around the steel pins,as the steel pins will become temporary magnets while in the magnetic field of the PMs. This in turn (virtually) increases the volume(weight) of the steel pins,and decreases the volume of the liquid ferrofluid.

So the net work done by the PMs on the steel rods on either side of the axis point sums to 0.


Brad

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #22 on: December 13, 2018, 04:41:02 PM »
@Carrol
The motor used on the buoyancy wheel might suffer from the difference in efficiency. This can be adjusted on regular DC-motors by turning the commetators a little bit one way or the other, so the timing on the rotating electromagnets is equal in both directions.
The reason why his device got more volume on one side than the other, is because of the angle between the wheels. This angle also increase the surface area in front of each tube which will cause greater force in front of the tube than behind them. This counterforce is caused by the same angle that makes greater volume on the wide side than the narrow side. So these two forces adds up to zero.
Btw, even if steel rods doesn't float on water, he could likely used steel rods instead of hallow tubes.
The difference in buoyancy is the same ;)

My ferrofluid is very slippery. It is some sort of silicone oil with magnetite powder in it.




@Brad
I can absolutely agree with you. Ferrofluid becomes a magnet. Strongest closest to the PM, but it also increase the pressure in the fluid which will make the steel rods more bouyant. Therfor harder for the steel rods to displace the fluid when they enter this area of higher compression. So what the magnetic field is attracting, the increased pressure will counterforce. So I don't think the attraction at the bottom is the main obstacle, but maybe it is.
However, something must account for conservation of energy. Cannot disagree on this.
I need to say that this is just a hobby. Much of my hobbies is creating problems at will, and then try to solve them - a troublemaker that cleans up after himself :)


Vidar

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #23 on: December 13, 2018, 05:39:27 PM »
3D printed bellow. I need to redo this one. Too poor bonding between the layers. And I need to extend it a bit with one more section.
https://youtu.be/qNNiBpVd5jg


Vidar

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #24 on: December 13, 2018, 08:22:54 PM »
Better but still small holes. Another material, with the same printer settings.


Vidar

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #25 on: December 13, 2018, 10:18:54 PM »
Finally a water proof bellow :)
I also cut the rods in two 5cm lengths.


Vidar

tinman

  • Hero Member
  • *****
  • Posts: 5365
Re: Magnetic flux control idea
« Reply #26 on: December 14, 2018, 12:05:38 AM »
@Carrol
The motor used on the buoyancy wheel might suffer from the difference in efficiency. This can be adjusted on regular DC-motors by turning the commetators a little bit one way or the other, so the timing on the rotating electromagnets is equal in both directions.
The reason why his device got more volume on one side than the other, is because of the angle between the wheels. This angle also increase the surface area in front of each tube which will cause greater force in front of the tube than behind them. This counterforce is caused by the same angle that makes greater volume on the wide side than the narrow side. So these two forces adds up to zero.
Btw, even if steel rods doesn't float on water, he could likely used steel rods instead of hallow tubes.
The difference in buoyancy is the same ;)

My ferrofluid is very slippery. It is some sort of silicone oil with magnetite powder in it.




@Brad
I can absolutely agree with you. Ferrofluid becomes a magnet. Strongest closest to the PM, but it also increase the pressure in the fluid which will make the steel rods more bouyant. Therfor harder for the steel rods to displace the fluid when they enter this area of higher compression. So what the magnetic field is attracting, the increased pressure will counterforce. So I don't think the attraction at the bottom is the main obstacle, but maybe it is.
However, something must account for conservation of energy. Cannot disagree on this.
I need to say that this is just a hobby. Much of my hobbies is creating problems at will, and then try to solve them - a troublemaker that cleans up after himself :)


Vidar

It is great to watch you carry this out to the end.
Looking forward to the outcome.

Remember,the conservation of energy only applies to a closed system.


Brad

Magluvin

  • Hero Member
  • *****
  • Posts: 5884
Re: Magnetic flux control idea
« Reply #27 on: December 14, 2018, 03:52:27 AM »
Just remembering some things Ive seen with ferro fluid. Have you experienced ferro fluid while in proximity to a magnet? I believe it hardens up. Like in some computer controlled shock absorbers they use field coils to control the ferro fluid to control the shock absorbing feature. So as I see the wheel will need to squeeze the fluid to keep the weight of it more on one side of the wheel. If you havnt tested the fluid first(if you did I must have missed that part), Id give that a go first. With water and gravity you wouldnt have that hardening issue and the water probably squishes around better with less resistance. Nice work.

Mags

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #28 on: December 14, 2018, 07:54:42 AM »
@Brad
Thanks Brad! This is a closed system, so conservation of energy is absolutely the law. Besides that, having the opportunity to print my own parts, cheap and flexible in the matter of shapes or material, is just great.


@Mags
Yes, you're right about the hardless. However, hardness is not the right term to use, because the fluid does not got denser - fluid is virtually incompressible, but the pressure in it increase when you approach a magnet.
I made a video this morning that demonstrates exactly that.
I used the cap for the ferrofluid box. Filled it with fluid, and tested two things:
One non-magnetic rod, and one magnetic rod that I just stirred back and forth.

My ferrofluid have too much oil in it, so it doesn't make these spikes you see on good ferrofluid close to a magnet.
The non-magnetic rod will not enter the fluid, because the pressure makes the rod too buoyant.
However, when I used the magnetic rod, it snapped right into the pond. Then I compared the magnetic attraction with a magnet without ferrofluid.
It is clearly less attractive inside the ferrofluid, but enough to overcome the buoyant effect.

Maybe a perfectly mixed ferrofluid, which is more magnetic, will balance the buoyant effect with attraction, so the steel rod doesn't "know" it is entering anything.
I think, however that would not make any difference for the experiments final outcome. But I just bought 400g magnetite powder so I can mix inn more magnetite into the fluid.
Estimated delivery is dec. 19th according to Ebay.

Here is the video of the ferrofluid vs magnetic, and non-magnetic steel rods:
https://youtu.be/mNQjKTvsb0k


Vidar

Low-Q

  • Hero Member
  • *****
  • Posts: 2847
Re: Magnetic flux control idea
« Reply #29 on: December 15, 2018, 03:02:48 PM »
After lot of mess, I have filled it up completely with ferrofluid. The gaskets keeps tight, and there is no leak.
When I try to squeeze the bellow, it is a relatively great friction that release suddenly. After that, the rods slides quite easy. But the rods will get temporary stuck at the very widest side and the very narrow side, each time the gaskets in the two wheels change direction along the rods. Also, it is different friction on each side, so the rods will be pushed out one way or the other while the wheels turn. However, I need only 60° rotation to see what is happening, because it is 6 rods.
Next is to print out a structure that holds the two shafts, one for each outer wheels/discs, so they get locked in an angle of approx +/- 15° in the horizontal plane.
I will post pictures later.


Vidar