Home made electromagnet

[drow13f]

Thanks that was very helpful. and now I have another question .
Is a magnets pulling power the same as its pushing power when pushing other magnets? or do I need a physics degree to determine that? I don't need exact just ball park. Example: A magnet with 100 pounds of lifting force. Will it push another magnet away with 100 pounds of force if like poles are together and will the combined force be the sum of the two magnets?
Im just trying to wrap my head around a few ideas here. Thanks

 

[rScotty]

Thanks that was very helpful. and now I have another question .
Is a magnets pulling power the same as its pushing power when pushing other magnets? or do I need a physics degree to determine that? I don't need exact just ball park. Example: A magnet with 100 pounds of lifting force. Will it push another magnet away with 100 pounds of force if like poles are together and will the combined force be the sum of the two magnets?
Im just trying to wrap my head around a few ideas here. Thanks

A physics degree would sure help. Study and practice works for the mind as well as the body. Athletes that practice and work out tend to be better for it. Also, science has a special language, and learning it makes it possible to communicate with other people who speak the same....thus multiplying your own knowledge.

No, the pulling and pushing forces are not equivalent. Magnetic forces are weird, and they follow odd rules compared to other forces. One difference is that magnetic forces are "pathway dependent". I'm sure you've seen the lines that magnets can make in powedered iron filings. Those lines represent the direction of the force, but it's not as easy to see that the path taken also influences the strength of the magnetic force too....but it does. With two magnets and some iron filings you can show that pushing versus pulling forces the magnetic force lines through different paths and therefore through different amounts of air and metal. Those different paths mean that the pushing and pulling magnetic forces will also be different.

In the simplest case, the repulsive forces will be stronger when two magnets are very close together. At greater distances the attractive forces dominate.
enjoy! rScotty

 

[8NLUGNUT]

So it sounds to me like I can take one of my drawbars and wrap it with wire, connect it to the lift arms, put the wires to the battery and drive around my property and pick up all the nails in the burn pile?

What am I missing?

 

[rScotty]

So it sounds to me like I can take one of my drawbars and wrap it with wire, connect it to the lift arms, put the wires to the battery and drive around my property and pick up all the nails in the burn pile?

What am I missing?

Neat idea! With a little work on the details it ought to work. I hope you try it. What you are missing is something you couldn't have known about. The quality is called "permeability" and what it means is how easily something can carry a magnetic field. A magnetic field will always take the easiest path that it can to complete its journey from North to South. Iron or steel is about 5000 times more permeable than air, so most of the field will go that way rather than fight to establish itself in the air around the bar. You want a magnetic field in the air around the bar, so you are going to have to figure out how to make that path through the air about 5000 times more attractive than the alternate path through the bar, down one lift arm, through the frame of the tractor, and back to the other end of the drawbar.

It's a fascinating problem. Let me give you a couple of hints: One, there isn't any such thing as a magnetic insulator. Air is a fairly poor conductor, but it isn't an insulator. The good news for the inventive chap is that it is relatively easy to redirect a magnetic field by using clever geometry and high permeability materials like steel. So although you can't block the field, you can bend it around with steel until you get an fairly short air gap right where you want it to be. The nail attracting work gets done in that air gap. In effect, the magnetic field is trying to shorten the poor part of its permeability path by attracting a material with a better permeability (the nail) into the worst part of the magnetic field path (the air gap)...
If this should a bit anthropomorphic that's OK; don't worry about it. We could say the same thing with math instead of words and it wouldn't sound so much like we had a magnet with free will following the tractor around...but frankly the results would still be the same.

Hmmm....how about a plastic or wooden draw bar with an electomagnet set into the middle? That might work. There are other possibilities too. With the alternator and the battery both pushing electrons as hard as they can you are still going to be limited to a nail-pulling field somewhere between an orange and a cantelope in size.
Keep working on it.
rScotty - with 2 Yanmars (one for sale!), an old rusty JD, and a newish Kubota.

 

[8NLUGNUT]

....anthropomorphic....

Wow, I didn't expect to see that word in a reply. Well done! We all do it but I can't even spell it.

I currently use a large horseshoe magnet to do the work and have considered attaching my rolling roofer magnet to the drawbar but I think the electro would be cooler and much stronger.

I'll have to think about this some more.

 

[lev man]

you can make a large room size magnet .

lol ok i will watch it tonight. ok so heres the thing. maybe itll help you get you guys to see a little more of what im getting at.

This is the hover chair.

HOVERIT - Changing the rules of conventional furniture.

I want that but not a chair. Just a flat surface i can stand on. but i dont want big bulky magnets i want magnets that is flat but about 20 by 25 inches or smaller, whatever necassary to get me able to stand on it. I was trying to get it to be electric so i can turn the hover on and off ya know so when i hit on it raises up. And i will have fishing line at the edges of the magnets or surrounding surface of the magnent so it doesnt fall off when i turn it on. Ya know what I mean? going for the hoverboard look.

 

[PhillAus000]

are you kiding me all i need is directions on how to make a magnet in electronics class help :confused2:



if any of you know where camp long lake is i work there

 

[Dr_Zinj]

I want something that will lift a weight equivalent to a Zumwalt class destroyer. Needs to put out a sustainable 18 to 20 Tesla strength field. And it needs to be able to run off a portable power supply. My 30 hp tractor's PTO just doesn't have the output necessary.

 

[rScotty]

are you kiding me all i need is directions on how to make a magnet in electronics class help :confused2:

Well, we probably could do that..
Any details? At the minimum, youu are going to need a cheap half inch bolt about six inches long, a large spool of about 25 to 35 gauge wire - probably copper wire - of the type that is insulated with varnish. Usually it has a red or green varnish on it. Then you need a battery holder that will hold 4 "D" cell batteries, and a six volt flashlight bulb in a holder.
Wind a coil of few hundred turns of wire over about 4" of the bolt length. Use tape as necessary. More turns are better. Nice if you can get 400 or 500 turns at least. Connect the coil to the battery...but be sure to put the light bulb in series with the connection so as to limit the flow of current. Connect the wires and it should pick up a half inch nut for the bolt at a distance of about 1/8".

(or you could cheat and just put the bolt through the already wound spool....
rScotty

 

[flyerdan]

A good cheap source for electromagnets is electric clutches from old air conditioning pumps. They have a round, potted core that pulls around 4 amps at 12 volts, if I recall. I was going to make a parking lot sweeper for a forklift with about 4 of them at one time. Cruise around and pick up junk, hoist it over the scrap bin and kill the power.