A Word On Permanent Magnetic Motors...

[Matthew Jones]

If you can remove the Neos from the side and see if it goes?

Also you could try shorting the length of the drive magnets and see what happens.

You should NOT have alot of resistance going in. Just a little bit then the thing should just take off. Mine works that way every time.

I'll so what can to help, so keep me updated.

Matt

[Shamus]

I tried that before I put the neos in, and just to verify I took them out again and it's the same result (the driven magnets oscillate and get stuck in the center of the array). There's resistance at the start of the track to the driven magnets (still quite a bit) but not as much as when the neos are in place.

I also tried a shorter stack of driven magnets (I assume that's what you meant? the 1/2" x 1/2" x 1/8" ones) and it locks up just like the long stack, and there's just as much resistance at the start of the track. The long stack is 27 magnets and the short stack I tried was 17. I'll try adding them one at a time, but I think I know what the result will be.

[Matthew Jones]

How are the 1/4' magnets placed? Is the North towards the inner part of the track or away. The little magnets should be with north pointed away from the track.
I suspect you have it right I just wanted to confirm. I am a little puzzled. I have built this configuration a few times all gave the same result.

Matt

[Shamus]

Just like you mentioned, the 1/4" x 1/4" ceramics are with N pointing away from center of the track. Dunno what's wrong, maybe the two halves are too close to each other?

Now that I think of it, in your video you have five 1/4" x 1/4" ceramics per group while in the drawing you posted it only showed four (I went by the drawing when building this). Could that be why it isn't working properly? Also, I couldn't tell from the video, but are your neos on the array 1" tall, or are they 7/8"? Again, hard to tell from the video but they look like they're the same height as the large ceramics (7/8").

Also of note, the S facing out neos at the end of the track don't seem to have much kick on the S side of the driven magnets. The repulsion there is *much* less than the repulsion of the N's against the N driven magnets on the other side.

[Matthew Jones]

I see one thing now that I look closer. On the sides. The Neo's, You have all of them close to the track. Rows 2-4 should be againts the small magnets. Also the small magnets should stick out a hair past the the larger ones. one magnets distance. Also the small magnets ,1/4', should not extend past the center of the large magnet. SO the whole quarter inch part of the assembly needs to be moved forward.

I broke my camera so I cannot show you a better shot.

Look at the video, at time 0:05 and pause. You'll see what I am talking about.

I guess I screwed up the drawing in that regard. Sorry about that.

My side neos are 7/8' tall by 3/8' wide.

You may also sand and oil that board if it sticky at all. Hard to tell. Something that may not be obvious is the fact that the Driven magnets get pushed down through the track. this may be causing more drag than you would expect. Thats why I use OILED Plastic.

I hope you got some extra magnets. I feel bad about the drawing I am going to fix that.

Matt

[Shamus]

Here's a close-up of a frame near the beginning of your video Matt that clearly shows five 1/4" x 1/4" magnets. And yes, I can see that they don't extend beyond the end of the large ceramic magnet that makes up the "bottom" of the magnet sandwich.

The track is made from MDF, not the least bit sticky. Also, I noticed that one end of the driven magnet stack is slightly levitated off the track (maybe by 1/8" or less) so I doubt that friction is playing a significant role in this.

I've also tried snugging the neos up against the 1/4" x 1/4" magnets, and it behaves exactly the same as in the other configuration. So there seems to be at least three problems with my replication: The neos on the array are the wrong size (1" x 1/2" x 1/8" vs. 7/8" x 3/8" x 1/8"), I'm one magnet too short in each section of the array with my 1/4" x 1/4" magnets, and they're positioned slightly wrong.

Could you do me a favor and measure all of your magnets for me? Just so I can make sure I'm getting the right sizes? I have a suspicion that the 1/4" x 1/4" magnets you're using are really 7/32" x 7/32".

[Matthew Jones]

Could you do me a favor and measure all of your magnets for me? Just so I can make sure I'm getting the right sizes? I have a suspicion that the 1/4" x 1/4" magnets you're using are really 7/32" x 7/32".

The size of those magnets aren't going to make difference, more the placement.
They cannot go past the center of the magnet in front of them. Thats the rule for those. Yours are past the center. I am not sure Its going to make difference though.
The package for mine say 1/4 by 7/8 inch. And thats what they measure. I bought them at Lowes. I can't find a link.

I have done this setup with several different kinds of magnetand work regardless.

You do have the 60 degrees between each side don't ya? It look like it I just want to make sure.

I'll make field image this evening in vizmag so you can see why it should work they may help some.

Matt

[Shamus]

Yeah, the angle is 60 degrees. I cut a special 30 degree wedge to make sure I got the angle right, and did a CAD drawing to double check against to see if it looked right.

Speaking of which, when you use 1/4" magnets in the CAD drawing, you can only fit four before running out of room, but if you scale them down to 7/32", they fit together very similarly to the track you showed on your video (with five small magnets in a row).

Can such a small, weak magnet shifted a small amount make such a big difference in overall field? I guess it can...

Small correction: I was intending to use MDF for the base of the track, but used a piece of solid wood instead. Still very smooth though, so I doubt friction is causing it fail.

[Matthew Jones]

Ya those 1/4 are critical. But the difference is hard to animate.

But I'll give it a try.
image 1 is modeled correctly:


Image 2 is modeled incorrectly:


Load both of them into previewer or into a browser and go back and forth between them. The difference is real subtle in the image. but you can the overall field shift to outside. This will cause problems.

But overall if you look at them you can see how each big magnet has an individual vortex from one corner. Thats the key.
You may need to change your configuration slightly based on the types and strength of magnet you have.

If I were you fix the small magnets placement and start seperating the sides wider until the thing will go through. If you getting alot cross flux between the 2 sides then you are canceling out the effect. That may be whats happening.

Do you have Green Paper to visualize the field. It can help. You'll clearly see the vortexs as they become stronger than anything.

Your neos are probably causing a problem too. Like you said they are to big. Try somthing smaller, Even the half inch ones your using for the track may work better. Just fix them so flush on top of the big magnets. You don't want the center (Bloch walls) between the outside and inside magnets to line up.

I have done it several times, and 2 other people that I know of have through a few delimas and made it work. So I know its doable
I realize you figured it should just work off the bat but unfortunately even the smallest changes have an effect.

Cheers
Matt

[astron]

Hi, I'm reading the book "The secret world of magnets" where the theory behind this magnetic gate is explained, and I found there is something you're probably missing out: the double vortex distribution of magnetic fields.

Illustration 1:


Illustration 2:


Illustration 3:




According to that, one corner on the north pole is magnetically connected to the opposite corner on the south pole of the magnet: these are the stronger vortices on the magnet. The other 2 vortices are weaker as you can see on the illustrations.

For example, if you look the topographic lines on illustration 2, you can see the strong corner on the north pole has a value of -100, but the weak corner on the same north pole is only +80.

So maybe it's not enough to simply place north facing the track, it seems finding the strong corner on the north pole of every magnet and align all of them facing the track properly should have an important effect on the performance of the gate. Maybe it will work smoother, or it will add some extra trust, I don't know, but I'll try to find out when I build my own gate to test the effect.

[Matthew Jones]

Read it some more and read the whole thread while your at it. You can also induce this asymmetrical behavior just by shorting out 2 corners. Which is exactly what the track does.

I have never looked for it and I can make it work 9 times out a 10.

Matt

[astron]

I know about the shorting method. I meant the big problem about this magnetic gate is the entrance and exit resistance, so what I'm saying is: find the strong vortex on the north pole of every magnet, then align all magnets with that vortex facing the track.


According to the theory, this is how the magnetic fields of a magnet look like:


So this would be a magnetic gate with all strong North vortices facing the track:

Maybe i'm wrong, but this could be a way to reduce the entrance and exit resistance and get a perfect alignment of magnetic fields on the middle of the track.

[Matthew Jones]

I know about the shorting method. I meant the big problem about this magnetic gate is the entrance and exit resistance, so what I'm saying is: find the strong vortex on the north pole of every magnet, then align all magnets with that vortex facing the track.
According to the theory, this is how the magnetic fields of a magnet look like:
So this would be a magnetic gate with all strong North vortices facing the track:
Maybe i'm wrong, but this could be a way to reduce the entrance and exit resistance and get a perfect alignment of magnetic fields on the middle of the track.

Ok so your gonna push this fact and nothing else HUH?. Here's my question to ya. How do you find that. You apparently have done this before, afterall look at the drawing?
Do you have plans and software available for Johnson's Gauss machine? You gotta design on your own?
Will a low budget 3d gauss meter give you these measurement on a magnet if you control it by hand?

Lay it on us. You have some you want to share that would be great. I would love to hear all about it.

Matt

[astron]

Ok so your gonna push this fact and nothing else HUH?. Here's my question to ya. How do you find that. You apparently have done this before, afterall look at the drawing?
Do you have plans and software available for Johnson's Gauss machine? You gotta design on your own?
Will a low budget 3d gauss meter give you these measurement on a magnet if you control it by hand?

Lay it on us. You have some you want to share that would be great. I would love to hear all about it.

Matt

WOW, I have no idea why did you reply to me like that!! Hope I didn't offend you too much, sir!

To find the strong vortex, any cheap gaussmeter should be enough. We don't need a perfect and exact reading, we only need to determine which is the strong vortex. Certainly I don't think it's possible to do it by hand, the gaussmeter should be attached to something like a 3-axis CNC machine to get a precise reading. I have this type of machine on my workshop and I could give it a try when I go back there in 2 weeks, all I need is to buy a gaussmeter. I will build my own prototype too.

Probably what I said is an important factor to take into account, probably it doesn't make any sense at all, I don't know. But whatever the case may be, at the very least you should show some respect to what others have to say here.

Lay it on us. You have some you want to share that would be great. I would love to hear all about it.

Yes, I want to share my opinion on a public forum. Do you have any problem with that??

[Matthew Jones]

I just don't think you realize the scope of the meter and the measurements that need to be taken to produce what your talking about.
I think you probably have an idea in your head yet you have no practical experience to back it up with. You read book now you know it all.

Go to your shop. Get a gauss meter with a PC interface and sit down and write some software to interact with it in real time. Have the software write out vector points in 3d space and make images.

When you get it all done and working. Then do your measurements and show us what were doing wrong.

Other than that I have the book too. I know how to read. In fact I have everything I can find on the subject. I have built somewhere around 400 assemblies to test. I have working prototype of the very track you drew, and many others that are more advanced and work better including the one we we're discussing.

So my point being is when your ready to share with us something that isn't just basic knowledge, something that come from experience, well then I would be happy to acknowledge you. But just few cut and paste to remind us what the book says well.... Your just barking up the wrong tree.

Read the whole thread and do your homework, make you look a little better on the introduction.

I am not interested in your opinion I am interested in facts based on testing.

Matt