electromagnetism...please help me out *pic*

[MrDudeMan]

to make a long story short, i need to have 2 magnets facing each other (north to north) that will be able to hold up 1000lbs


i found some electromagnets online that take 48w to power and can lift 610lbs...but that does that mean they also repel 610lbs? so if i took 2 of these, put the norths toward each other, and then put a thousand pounds on it, it wouldnt completely push together, right?


can someone help me out please



pic of what i mean here

 

[tranceport]

You would first need to place them in some sort of guide. The opposite ends are going to want to attract so greatly that they will force a flip and then slam together.

I do believe pull force is equal to push force. If you have ever held a magnet north to south it pulls greatly. Then held it north to north it pushes greatly but the force seems less because it is push away therefore less force is applied. If it is pulling together the force is increased as they move closer together. I will have to search for some evidence on this. Gravity will also play a role.


Cheers,

Tranceport

 

[MrDudeMan]

Originally posted by: tranceport
You would first need to place them in some sort of guide. The opposite ends are going to want to attract so greatly that they will force a flip and then slam together.

I do believe pull force is equal to push force. If you have ever held a magnet north to south it pulls greatly. Then held it north to north it pushes greatly but the force seems less because it is push away therefore less force is applied. If it is pulling together the force is increased as they move closer together. I will have to search for some evidence on this. Gravity will also play a role.


Cheers,

Tranceport

yes...a person that knows some stuff...thanks!


i have a whole assembly built to make this work (so they dont flip that is) but i was just asking for the theory of it. so you think the push force would still be very strong? it doesnt need to be as strong as the pull force, but hopefully it will still be strong enough to hold up at least 300lbs between the 2 if north is facing north. does that sound reasonable?

TIA,

Tony

 

[tranceport]

Yes it does. As long as you have the guides setup already. Heck you could even remove one magnent and just apply 610lbs of force.

 

[Mingon]

I do believe pull force is equal to push force. If you have ever held a magnet north to south it pulls greatly. Then held it north to north it pushes greatly but the force seems less because it is push away therefore less force is applied. If it is pulling together the force is increased as they move closer together. I will have to search for some evidence on this. Gravity will also play a role

I am not going to say this isnt true (as I am not totally sure) but I would say that the likelyhood that it seems easier when pushing is that your muscles in your arms are stronger moving inwards (assuming your not pigeon chested ) but the muscles in most people arms are weaker in the outward direction hence pulling apart is harder.

 

[MrDudeMan]

Originally posted by: Mingon

I do believe pull force is equal to push force. If you have ever held a magnet north to south it pulls greatly. Then held it north to north it pushes greatly but the force seems less because it is push away therefore less force is applied. If it is pulling together the force is increased as they move closer together. I will have to search for some evidence on this. Gravity will also play a role

I am not going to say this isnt true (as I am not totally sure) but I would say that the likelyhood that it seems easier when pushing is that your muscles in your arms are stronger moving inwards (assuming your not pigeon chested ) but the muscles in most people arms are weaker in the outward direction hence pulling apart is harder.

thats a good way to think about it actually, and probably something most people dont realize....hmm

i hope this project works out...if you guys are interested i will post lots of pics and maybe even a video of it working

 

[Mingon]

thats a good way to think about it actually, and probably something most people dont realize....hmm

Thats what asberger's and 10 years as a scientific engineer does for you.

 

[Smilin]

Originally posted by: MrDudeMan
to make a long story short, i need to have 2 magnets facing each other (north to north) that will be able to hold up 1000lbs


i found some electromagnets online that take 48w to power and can lift 610lbs...but that does that mean they also repel 610lbs? so if i took 2 of these, put the norths toward each other, and then put a thousand pounds on it, it wouldnt completely push together, right?


can someone help me out please



pic of what i mean here

Something to remember: thats 610lbs of pull you're talking about. Pull occurs and is measured when the two surfaces are in contact. This amount of force won't be evident in a compressing situation until the moment the surfaces touch. If they are not touching then the force is going to fall off with the square of distance.

With that in mind your idea might support 1000lbs of force applied slowly but if you are trying to set something down on this your magnets might smack together.

Are you making a new floppy disk holder? What's this for?

 

[Smilin]

Nother question...

600+ lbs of force provided by a 13lb coil: Be careful you don't accidentally invent the worlds first magnetic @ss cannon and end up in the darwin awards cuz you shot your jewels off.

 

[Smilin]

Ok last question and I promise I'll leave your post alone

Instead of a cylinder around the outside of the magnets have you thought of just having a big dowel run down the middle? Fix the lower magnet to the base and fix the upper magnet to the seat, but then attach some sort of non-ferrous cylinder that runs down the middle from the seat. You can then set the length of this about 1/8 inch too long and it will stop the magnets from smacking together.

 

[MrDudeMan]

Originally posted by: Smilin
Ok last question and I promise I'll leave your post alone

Instead of a cylinder around the outside of the magnets have you thought of just having a big dowel run down the middle? Fix the lower magnet to the base and fix the upper magnet to the seat, but then attach some sort of non-ferrous cylinder that runs down the middle from the seat. You can then set the length of this about 1/8 inch too long and it will stop the magnets from smacking together.

bother my post as much as you want, i enjoy your replies


the magnets we were gonna get were WAY too expensive, so what i got instead are two neodynium magnets. i am eventually going to get a lot more of them and lay them down flat for a "floor" type of thing for my seat. i dunno how to explain it but its gonna be sweet.


so as of now, we are going to mess around with 2 of these SUPER strong magnets and see how much weight they really repulse at a given distance, and go from there. i will keep you guys updated!

 

[Smilin]

Our company makes these pneumatic cylinders of various types. We actually have one that curves! I wondered for a long time how the heck they did it..I mean they would have to have the piston inside with a curve too...but some of these actually S curve.

Turns out they make them with magnets. Basically they just have a magnetic piston head with no arm on it. Air pressure shoots this magnetic plate back and forth inside the cylinder and a ring magnet on the outside holds whatever load you are trying to move.

We use some of these spare magnets from the really small cylinders to shoot each other with. You just put one magnet on a ballpoint pen and then slide another down over the top of it with the polarity reversed. With a little skill you can nail someone a couple cubes down. For their size these are probably the strongest magnets I've seen. If you get the half-dollar sized magnetic rings you have to be careful not to let them snap together or they take a chunk of your fingertip with it.

This little trick we do is what made me think of putting a support cylinder coming down from your seat and going inside the two magnets. You shouldn't have to worry about any lubrication to keep the upper part moving smoothly...it will just freely float.

Another side note: Infinity makes these tweeters for your speakers that are two flat plate magnets with long vertical slots cut in them.. They bolt them together with the polarity reversed and a foil type metal inbetween. All you do is put a signal through the foil and it vibrates all over the place because of the strong magnetic field it's in. Nifty things...tough to get back together right though

 

[MrDudeMan]

i got my magnets from guassboys.com and if you go look at their crazy pics...they really are crazy! its amazing how strong neodymiun really is. this project should be fun!

i ordered 2 last night, so they should be here soon hopefully!

 

[Adul]

wow this sounds like afun project i want to see pics of it when you are done/ hell why not document it

 

[MrDudeMan]

Originally posted by: Adul
wow this sounds like afun project i want to see pics of it when you are done/ hell why not document it

i will do my best to take pics of the whole process

 

[gururu]

The thing to note is that the strength (repulsion or attraction) of a magnet is strongest from north to south or vice versa. When the magnets are lined up as you have them, the strengths of repulsion and attraction decline significantly. Therefore, I don't think you'll achieve your required repulsion parameter to resist 1000 pounds. The magnets will be forced together.
If your theory is correct, I think it will be important to ensure that the braces holding the magnets can withstand a thousand pounds of pressure. You will have a thousand pounds of force trying to make the magnets rotate (one clock, one counterclock). I wouldn't use wood.

 

[MrDudeMan]

Originally posted by: gururu
The thing to note is that the strength (repulsion or attraction) of a magnet is strongest from north to south or vice versa. When the magnets are lined up as you have them, the strengths of repulsion and attraction decline significantly. Therefore, I don't think you'll achieve your required repulsion parameter to resist 1000 pounds. The magnets will be forced together.
If your theory is correct, I think it will be important to ensure that the braces holding the magnets can withstand a thousand pounds of pressure. You will have a thousand pounds of force trying to make the magnets rotate (one clock, one counterclock). I wouldn't use wood.

i guess i have not put as much info in this forum as i have at the 4hv.com forums...we changed the plan. we are using normal magnets instead of electromagnets now.

 

[Smilin]

Originally posted by: gururu
The thing to note is that the strength (repulsion or attraction) of a magnet is strongest from north to south or vice versa. When the magnets are lined up as you have them, the strengths of repulsion and attraction decline significantly. Therefore, I don't think you'll achieve your required repulsion parameter to resist 1000 pounds. The magnets will be forced together.
If your theory is correct, I think it will be important to ensure that the braces holding the magnets can withstand a thousand pounds of pressure. You will have a thousand pounds of force trying to make the magnets rotate (one clock, one counterclock). I wouldn't use wood.

I don't think they'll try to rotate. He's doing top-bottom north-south.

 

[Peter]

The main problem I see here is that the seat is going to shoot up when there's no load applied ... I smell a Darwin Award here.

 

[Howard]

Darwin awards are overrated. I got one and I don't feel any different.

 

[lobadobadingdong]

Originally posted by: tranceport
You would first need to place them in some sort of guide. The opposite ends are going to want to attract so greatly that they will force a flip and then slam together.

I do believe pull force is equal to push force. If you have ever held a magnet north to south it pulls greatly. Then held it north to north it pushes greatly but the force seems less because it is push away therefore less force is applied. If it is pulling together the force is increased as they move closer together. I will have to search for some evidence on this. Gravity will also play a role.


Cheers,

Tranceport

If I remember right from physics the pull=push is true, however distance is also a factor and is is exponentional in concept that pull=push is only true when the objects are at equal distance and remain constant so that X feet between the magnets depending on polarity is reduced when X>0.00 exponentially past the point that the magnetic differences can no longer be detected.

laymans, the farther the magnets get away from each other the less lift you will have. I would suggest using a non or anti-magnet material such as thick pvc for a center poll to guide them to reduce the ability of the S poles to try to pull toward the N poles of the opposing magnets.

 

[Peter]

Originally posted by: Howard
Darwin awards are overrated. I got one and I don't feel any different.

No you didn't. 'Cause to qualify for one, you need to DIE from your own stupidity.

 

[gururu]

LOL. That's right! It's all about selection baby! You sure don't want a Darwin award!
darwinawards.com

 

[Smilin]

Originally posted by: Peter

Originally posted by: Howard
Darwin awards are overrated. I got one and I don't feel any different.

No you didn't. 'Cause to qualify for one, you need to DIE from your own stupidity.

He might live through this one and still get an award due to damaging his ability to reproduce.

 

[Peter]

That'd just get him an honourable mention