There is a lot of people telling us that placing magnets in repel mode will demagnetize them.
But many of those people have used inferior magnets in their test, like cheap ferrite.
And then we hear over and over again that repelling magnets will demagnetize them.
But that might not be true if you are careful and use neomagnets of the same size,
shape and strength in repel mode. Then the fields are equal in strength.
Please read the question at this link. It explains my concern.
http://www.overunity.com/index.php/topic,2451.msg39543.html#msg39543
I think we have to sort out the risk when using good quality NdFeB magnets.
So, if we have two equally strong neo magnets of the same size and shape
they should be able to operate in repelling mode without demagnetization.
I have attached a demagnetization graph on several types of magnets.
But I have trouble understanding how to read it. Can someone here explain
how to see what type of field it takes to demagnetize the N38 in the graph?
It might clarify wether it can withstand or not to be demagnetized of a similar
external field as the N38 holds.
Quote from: Honk on July 13, 2007, 04:14:22 AM
There lot's people telling us that putting two magnets in repel will demagnetize them.
The above sentence makes absolutely no sense because the noun "magnet" is missing an adjective.
But many of those people have used inferior magnets in their test, like cheap ferrite.
And then we hear over and over again that repelling magnets will demagnetize them.
But that might not be true if you are careful and use neomagnets of the same size,
shape and strength in repel mode. Then the fields are equal in strength.
Please read the question at this link. It explains my concern.
http://www.overunity.com/index.php/topic,2451.msg39543.html#msg39543
I think we have to sort out the risk when using good quality NdFeB magnets.
So, if we have two equally strong neo magnets of the same size and shape
they should be able to operate in repelling mode without demagnetization.
If people would simply ask NEO manufacturers this question instead of speculating, they would have the answer:
Two NEO magnet can not weaken or demagnitize each other in repel mode. If not heated excessively or violently vibrated, the great-great-grandchildren of your great-great-grandchildren will not be able to measure any weakening of NEOs in repell mode.
People who say that NEOs can demagnetize themselves, usually can not tie their shoes on in the morning.
End of discussion.
Earl,
Did your information come from a Neo manufacturer or have you been working for one?
I have not noticed any weakness from using them in a working magnet motor (using my design). Do you have any figures when magnets are used at certain velocities with one another? Or does this make any difference to the "pinning material" within the magnet?
Thanks.
My theory is that a stronger magnet will demagnetize the weaker one... If the magnets are all the same material, shape, size and strenght no demagnetization should take place. no matter what configuration you place them in...
Quote from: Duranza on July 13, 2007, 09:39:15 AM
My theory is that a stronger magnet will demagnetize the weaker one....
If the magnets are all the same material, shape, size and strenght no demagnetization
should take place. No matter what configuration you place them in...
That's my point exactly, but it would be nice to have some calculations or graph understanding
to back this idea instead of just guessing.
I'd like to design a Wankel motor at repel mode but then I need to know more about the risks.
Hey all of you guys out there. Please tell us what you know about this subject. (Other than guesses)
Try this experiment...
Get hold of a donut shaped magnet, one from the back of a loudspeaker will do just fine, and break it into two pieces. Now try and put the two pieces back together... They will repell each other apart. So the people that say magnets can not be used in repel mode, are they saying that a donut magnet de-mags all by it's self ?. Hmmm !.
Quote from: Bulbz on July 13, 2007, 10:46:54 AM
Try this experiment...
Get hold of a donut shaped magnet, one from the back of a loudspeaker will do just fine, and break it into two pieces. Now try and put the two pieces back together... They will repell each other apart. So the people that say magnets can not be used in repel mode, are they saying that a donut magnet de-mags all by it's self ?. Hmmm !.
http://www.overunity.com/index.php/topic,2451.msg39543.html#msg39543
@ Honk...
Yeah, I understand the two magnets of equal size and strenght wont de-mag in repel mode, but... What if the two broken pieces are from the same magnet but are different sizes. Lets say that when the magnet is broken in two but one piece ends up as 1/3 of the parent magnet and the other piece is 2/3. Will the two un-equal parts of the same magnet de-mag each other in this scenario ?.
Good question. I don't know.... Perhaps someone else here can help?
I don't think that a static repulsive field like clamping 2 magnets together will change much, since the magnetic domains will 'holdup'. But when the repulsive field is pulsing it a different story, probably much like hammering a nail in wood. You can let a 200kg hammer rest on a nail and it won't sink the nail into the wood. Because the structure of the wood will 'holdup' the static pressure of the hammer. But you CAN take a 0.1kg hammer and hammer the nail with a rate or frequency and it will drive the nail in the wood. The actual 'action matters'
I thing...
Sorry, but I don't buy the hammer theory when it comes to magnets.
There is no mass involved when presenting two flux fields to each other.
We need some hardcore facts and stop guessing.
I will have to contact a manufacturer and hear what they have to say about it.
You all have no idea of how NEO material is magnetized and what physical pieces and energy are necessary. In order to magnetize NEO material, one needs high-voltage capacitors discharging mucho mucho Amperes into a magnetizing coil. The magnetizing coil has ferric material in it, which funtions at first, but as the Amperes climb the iron saturates and the magnetizing coil becomes an air-core coil, which needs then still more amperes to saturate the NEO material. By mucho Amperes, we are talkiing about tens, hundreds, thousands, even tens of thousands of Amperes, even if only for a short time. Lots and lots of joules.
A NEO magnet can neither saturate NEO material nor demagnitize another NEO magnet.
Forget completely about successfully magnetizing or demagnetizing one NEO magnet by another.
NEO magnets are not called super magnets for no reason.
Earl
@ Earl...
Thank you for the enlightenment ;D.
I don't buy it just yet. I'd like some more information.
Yes, we can all read about the magnetization process of neo magnets on the internet
but there's very litte or no information on the demagnetization process except heat.
Have anybody here ever had a neo demagnetize or getting somewhat weaker when repelled?
Or have all those spreading the rumor used ferrite or alnico magnets.
Quote from: Honk on July 14, 2007, 02:55:32 AM
I don't buy it just yet. I'd like some more information.
Yes, we can all read about the magnetization process of neo magnets on the internet
but there's very litte or no information on the demagnetization process except heat.
Did it ever occur to you that that is the only way to demagnetize a NEO magnet with the exception of putting it into a HV magnetizer and zapping it halfway?
Have anybody here ever had a neo demagnetize or getting somewhat weaker when repelled?
This never happens.
Or have all those spreading the rumor used ferrite or alnico magnets.
Finally, finally the light goes on! It sure took a while until you understood. Ferrite and alnico magnets not only demagnitize in repelling mode, they demagnitize just sitting there.
Why do you think all alnico horseshoe magnets always are delivered with an iron keeper bar?
Why is it called a keeper bar?
Why are NEO magnets the only ones that are manufactured in thin discs?
People who say NEO magnets can demagnitize in repelling mode are dumb sh!ts.
For the very last time, NEO magnets are SUPER magnets and have not the slightest link whatsoever with all previous magnetic materials such as ferrite or alnico. NEOs are in a completely different universe than all other previously discovered magnetic material. You can not compare apples with zebras.
If you don't buy it, that is your problem.
Regards, Earl
QuoteI don't buy it just yet. I'd like some more information.
Yes, we can all read about the magnetization process of neo magnets on the internet
but there's very litte or no information on the demagnetization process except heat.
Did it ever occur to you that that is the only way to demagnetize a NEO magnet with the exception of putting it into a HV magnetizer and zapping it halfway?
Have anybody here ever had a neo demagnetize or getting somewhat weaker when repelled?
This never happens.
Or have all those spreading the rumor used ferrite or alnico magnets.
Finally, finally the light goes snip
Oh thank you holy magnet God for throwing us undeserving nerds these nuggets of pure magnetic gold. We don't deserve your holy presence here, grovel , grovel, we are just poor untutored magnetic imbeciles crouching in your immense magnetic shadow, grateful for the smallest turd you deem worthwhile to excrete out of your great magnetic arse.
@acp...
:) ;) :D ;D :P. ROFL
@acp...
:) ;) :D ;D :P. ROFL
[edit] No offence Earl, but that post from acp was funny ! [/edit]
OOPS !...
Sorry for the double post, I think my brain is still mashed due to all that beer I drank last night, and I don't know how to remove one of them.
If this is the case with neos then a repelled motor is the most attractive design to build.
If acp feels like a "poor untutored magnetic imbecile" that is his problem, not mine.
His post did not help anyone, so I consider it pretty pathetic.
Earl
Quote from: Bulbz on July 14, 2007, 08:17:17 AM
@acp...
:) ;) :D ;D :P. ROFL
[edit] No offence Earl, but that post from acp was funny ! [/edit]
Quote from: Honk on July 14, 2007, 04:30:59 PM
If this is the case with neos then a repelled motor is the most attractive design to build.
Honk,
design of electric motors can be very complicated with lots of things to consider.
Looking at things purely in a traditional manner, it doesn't matter whether attracting or repelling.
Once you get over the non-problem of repelling mode weakening NEOs, than you are free to choose atraction or repulsion.
I personally feel repulsion offers non-traditional "bizare" anomolies that attraction mode can not offer so easily. There is a believable rumor coming from an ex-hippy that his commune in San Francisco in 1969 developed a motor generator that had excess power. When the battery was disconnected, the motor kept running. His part in the development was mechanical, so he didn't understand the electrical part very well, but enough details have come out to permit a replication. Since I heard about this, I have spent some years studying the actions of repelling and rotating magnetic systems. I believe there are scientific reasons to explain how such a repelling motor could capture excess energy. The hippy commune used a rotor disk of 3 magnets and two stator coils, plus a bunch of collector coils. I have not had the time to replicate this motor/generator, but if anyone has time and electromechanical abilities to do so, I can explain how to build it and some things to avoid doing.
Regards, Earl
Have you personally tried neos in repel mode in your designs?
If so, for how long did you run your machine under load? Weeks, month or years?
This same debate is going on in an alternate location...
http://www.overunity.com/index.php/topic,2770.msg40186.html#msg40186
My 2 cents are in there...
~Dingus Mungus
OK....... All:
This from NW Magnets. You can surely demagnetize one magnet with another. Take a grade 8 ferite and an N38 NeoD and the neo will win out every time. The ferite cannot hold up. Two neo's will not. Thats as far as he went on the subject. Hope that helps out a bit here. So I see I will need to use neos of the same size and grade just to make sure but dont see a problem in my mag motor.
thaelin
Honk,
I built a wankel motor a couple years ago. This motor used repell mode. It would only run two days before the magnets were gone. I used the same size magnets in it through out. And yes I used NEOs(N48).
I never did figure out what caused them to go bad, but they did. Maybe the rpm or something, I dont now.
I know I'm going to catch hell for this, but I tryed it, didn't work.
Later,,,,,,JackH
Repel motor using N50 here ran for 4 days and dead.
Alittle bit about demag, Sorry its not much .
http://video.google.com/videoplay?docid=1681787127575536292&q=Walter+Lewin&total=91&start=0&num=10&so=0&type=search&plindex=3
message deleted
Quote from: IronHead on July 18, 2007, 10:38:55 PM
Repel motor using N50 here ran for 4 days and dead.
Alittle bit about demag, Sorry its not much .
http://video.google.com/videoplay?docid=1681787127575536292&q=Walter+Lewin&total=91&start=0&num=10&so=0&type=search&plindex=3
IronHead
Thanks for the link.
On a side note also on the same page, this is very interesting:
M.I.T.-Walter Lewin- Complete Breakdown of Intuition - Part1
http://www.youtube.com/watch?v=eqjl-qRy71w&mode=related&search=
and definitely this, where he actually does the experiment and measures/records the 2 Vs !
M.I.T.-Walter Lewin- Complete Breakdown of Intuition - Part2
http://www.youtube.com/watch?v=1bUWcy8HwpM&mode=related&search=
Possibly useful for the TPU and related replications too?
Good stuff
Iv'e been having two N50M neos in repel mode for 3 month now and I measured them yesterday to
see if they had lost any of their strength. Well, they hadn't lost anything. They were as good as new.
The originally measured 0.51 tesla on the surface and 3 month later in repel they still measure 0.51 tesla.
Maybe they won't become demagnetized when just sitting still. Perhaps motion is required???
I might build a rotating repel test machine later on to see if they can handle that to.
Quote from: Honk on September 04, 2007, 12:30:49 PM
Iv'e been having two N50M neos in repel mode for 3 month now and I measured them yesterday to
see if they had lost any of their strength. Well, they hadn't lost anything. They were as good as new.
The originally measured 0.51 tesla on the surface and 3 month later in repel they still measure 0.51 tesla.
Maybe they won't become demagnetized when just sitting still. Perhaps motion is required???
I might build a rotating repel test machine later on to see if they can handle that to.
Hi Honk,
Thanks for showing this. May I suggest to check the magnets temperature when you first try the same test with motional Neos. IF eddy currents are involved they will heat up the Neos and this may cause some demagnetization in time.
Gyula
I thought I might ask here (sorry of topic)
does anyone know of a good 3d fem software for magnet research
My email is mark.dansie@advatel.biz
Thanks
I got some new information from a source connected to the manufacturing of neodymium magnets.
Quote:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
The force field in a magnet is static even if the magnet is moving, That has got to do with the source of the force.
The source of the force field in a magnet is the magnet itself, due to the molecular alignment. Hence the description "static".
In an electromagnet, the force is "dynamic" because there is a flow of current. It's the Amperes that demagnetise the magnet.
And to demagnetise it, the whole magnet must be inside the force field of the electromagnet. In a rotating motor only the poles/tips
are exposed, hence degradation is not present. There is always some shape degradation (natural los of power) but that is irrelevant.
For Neo magnets its around 5-10% in 100 years. That's all.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
This seems to make real sense. There is no demagnezitation of Neodymium magnets in repel mode. End of story.
Now all of you repel mode builders can start building your motors without any risk of demagnezitation. Good luck.
Quote from: Honk on July 13, 2007, 04:14:22 AM
There is a lot of people telling us that placing magnets in repel mode will demagnetize them.
But many of those people have used inferior magnets in their test, like cheap ferrite.
And then we hear over and over again that repelling magnets will demagnetize them.
But that might not be true if you are careful and use neomagnets of the same size,
shape and strength in repel mode. Then the fields are equal in strength.
Please read the question at this link. It explains my concern.
http://www.overunity.com/index.php/topic,2451.msg39543.html#msg39543
I think we have to sort out the risk when using good quality NdFeB magnets.
So, if we have two equally strong neo magnets of the same size and shape
they should be able to operate in repelling mode without demagnetization.
I have attached a demagnetization graph on several types of magnets.
But I have trouble understanding how to read it. Can someone here explain
how to see what type of field it takes to demagnetize the N38 in the graph?
It might clarify wether it can withstand or not to be demagnetized of a similar
external field as the N38 holds.
My experience is that one stronger magnet can demagnetize another weaker magnet.
Not even two ferrite magnets with same stregth can demagnetize each other, but if you take a neo magnet, and a ferrite magnet, the ferrite magnet will change polarity instantly when the neo magnet are close enough.
I have glued two small disc neomagnets together, equal poles facing. Then I putted them in my drawer, and after a very long time I forgot it was there, so recently I found them in my drawer. I separated them but the magnetism dont seem to weaken much. They must have been together for a year now.
My experience.
Vidar
Quote from: IronHead on July 18, 2007, 10:38:55 PM
Repel motor using N50 here ran for 4 days and dead.
Alittle bit about demag, Sorry its not much .
http://video.google.com/videoplay?docid=1681787127575536292&q=Walter+Lewin&total=91&start=0&num=10&so=0&type=search&plindex=3
The demagnetized motor you talking about is it a magnet only motor (stator rotor setup with magnets) with no electricity applied? Or an electromagnet motor as Honk suggested above?
THanks
Quote from: Honk on October 28, 2007, 06:33:37 PM
I got some new information from a source connected to the manufacturing of neodymium magnets.
Quote:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
The force field in a magnet is static even if the magnet is moving, That has got to do with the source of the force.
The source of the force field in a magnet is the magnet itself, due to the molecular alignment. Hence the description "static".
In an electromagnet, the force is "dynamic" because there is a flow of current. It's the Amperes that demagnetise the magnet.
And to demagnetise it, the whole magnet must be inside the force field of the electromagnet. In a rotating motor only the poles/tips
are exposed, hence degradation is not present. There is always some shape degradation (natural los of power) but that is irrelevant.
For Neo magnets its around 5-10% in 100 years. That's all.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
This seems to make real sense. There is no demagnezitation of Neodymium magnets in repel mode. End of story.
Now all of you repel mode builders can start building your motors without any risk of demagnezitation. Good luck.
HONK are you/above saying that when people are using the Wankel design utilizing an electromagnet they are demagnetizing their motor within days (are the peoples who's motors died within days using the Wankel design with electromagnet)? They were not specific. If so basically a magnet motor which only uses magnets without an outside source such as electromagnetism should not have their Neo's demagnetized once and for all as you mentioned?
Anyone here that can help with my above post? I am about to receive and apply my new magnets. Thanks