Introduction: Make a Simple Electromagnet

Picture of Make a Simple Electromagnet

Ever have a project that needed a certain kind of magnet, yet you didn't have what you needed? Maybe you wanted to be able to switch the magnet on and then off, but lack the knowledge on how to create such a wonderful thing? Now (after following my steps) you'll know how to make a basic one.

I needed to create an electromagnet for a project, so I decided to document the steps to show how to create your very own electromagnet.

Warning: The more current you place through the wire, the more heat it will give off and could start a fire if it becomes too hot. The wires will be hot after putting current through them. You can use thicker wires to allow more current. Recommended wire type is copper.

1. Phone Line (or small insulated copper wires such as magnet wire)
2. Wire Stripper
3. Scissors
4. Pliers
5. D Batteries (power source)
6. Tape or glue
7. Ferrous metal object such as a pipe or nail
8. Small ferrous object to test with (small screw, nail, etc.)
9. Time on your hands

Step 1: Simon Says: Strip!!!

Picture of Simon Says: Strip!!!

1. Strip the phone lines of their outside sheathing. Don't cut into the interior wires. As you move along, you'll need to use the pliers to push the sheathing off. If you can, try to strip at least two to three feet (that's all you'll need to make this simple magnet).

2. Bare the ends of the wires (If you had to cut the wires, bind the bare ends together to create a long wire and place tape over the bare spots). Now take one end and place it up next to the metal object you wish to make into a magnet.

3. Either glue or tape it into position to prevent it from unraveling.

4. Now start wrapping your wire around the metal object as shown in the video below.

Step 2: Finish It Up

Picture of Finish It Up

1. After you've wrapped the wire around several times (Only wrap wire in one direction, otherwise your magnet will be weaker due to the fields fighting against each other) you can tape, glue, or tie a small knot at the end.

Note: Don't wrap the entire metal pipe. The part that has wire will not attract ferrous objects. You need to leave metal showing to use as a magnet.

Now you're all set to test out your new electromagnet.

2. Set up the battery so that it sits on one of the bare wires and hold the other end of the wire in your hand (Don't touch the copper. It'll become hot). Now touch the wire that you're holding to the top of the battery and place your test object near the metal pipe. You may not feel the fields (depending on how much power you're putting through the wires and how many times you wrapped the object), but if you place the test object near the pipe, it should be attracted to it.

Video below....

Step 3: Making It Stronger and Adding a Handle

Picture of Making It Stronger and Adding a Handle

See video below:
To make your electromagnet stronger, after you tie the knot (or tape/glue) the end into place, pull the wire alongside the wrapped wire to the starting point and start wrapping the wire around on top of the already wrapped wires. Make sure you go in one direction as you wrap. You can do this as many times as you want, but remember the farther away you get from the center (the metal pipe), the weaker the fields will become.

Note: The magnet's fields won't become weaker, just the coils' fields.

To make a handle:
1. Pull both wires towards the back away from the metal magnet
2. Wrap the wires with electrical tape to keep them from sliding around.
3. Place a piece of foam pipe insulation around the wires. Trim as needed to make a snug fit.
4. Wrap the foam insulation with electrical tape to keep it in place and help prevent heat from leaking out.

Note: Either use a small current if using the electromagnet for long periods or use the magnet for short periods of time if using a good amount of current. Coils = Resistance which give off heat.

There you go, you're all done.


CharlieC (author)2008-11-21

I have read your instructions on making an Electro Magnet, but wanted one very strong; so I used a 3/8 X 6 inch bolt. I wrapped it 8 or 10 times with 18 AWG Magnet Wire. It doesn't work with a D-Cell or a 9-volt battery, so I hooked it to a car battery, which made the strong magnet that I need. however, the wire and bolt got very hot, very quickly. If I can get this working, it will be used in a very rapid, steady "on-off" situation. What must I do to accomplish my goal?

ross man (author)CharlieC2012-05-07

have you tried covering it whith electric tape?

Sourav Ganguly (author)ross man2016-11-13

If I cover the whole thing with electric tape ,will it affect the magnetic field or electromagnetic waves ...

ziezie32 (author)CharlieC2011-03-09

use gloves so you won't burn yourself

ross man (author)ziezie322012-05-07

yes u can use gloves but what about the surface that it is sitting on

ross man (author)CharlieC2012-05-07

have you tried covering it whith electric tape?

Nightcrawl (author)CharlieC2010-10-13

Better late than never Charli :).

To get a strong electromagnet, you will be basing your build off of what kind of current (amps) you can get, and the number of turns.

The more current you get, the more crowded the wire is for the current to pass through, so it will become hot. To reduce the amount of heat building up, you will want to use thicker wires.

If that's not possible, then perhaps a resistor connected in series would help reduce the current to a level that doesn't heat the wires. You will limit the strength of the magnet by doing this. A lower current can be compensated for with even more turns.

Magnetic force = I * N where as I is current and N is amount of turns.

This is somewhat simplified and english is not my native language. I hope this might help you, or anyone else out there reading this.

blade97 (author)Nightcrawl2011-07-15

by doing that it may make it even hotter as you have all the resistance from the resitor plus the wire would make it hotter

vela.u (author)Nightcrawl2011-01-27

i like ur info NIGHT CRAWL
its gud

tmac78 (author)Nightcrawl2010-11-15

Nightcrawl== the equation "magnetic force = I * N" is helpful, but what unit of measurement is relevant? for example, is the force measured in Pounds/ square inch?

The reason I ask is that I need to create a magnet with approximately 50 pounds of pulling power. This magnet needs to be switched on/off quickly and repeatedly, most likely with a "squeeze" trigger. Can you possibly give me the necessary specs to create this kind of magnet? Thank you very much for your help, and anyone else's suggestions are welcomed and appreciated.

ross man (author)2012-05-07

i have tried countless times to make a electromagnet to put under a grinder to pick up the little grinds but a epic faliure hits every time

vela.u (author)2011-01-27

it is a waste of tym
i didn't understood a bit

kj0001 (author)2010-10-24

how do you make a stronger electromagnet so you could put one in a glove with a switch?

octavian234 (author)2010-08-23

I wrapped a strand of the ethernet cord around a iron nail and attached the leads to a D battery. The wire got really hot but I couldnt get any magnetic pull on the second iron nail i had right next to it

pyrorower (author)2009-12-14

Just wondering, do the wire have to be solid or can it be a stranded wire?

octavian234 (author)pyrorower2010-08-23

I'm pretty sure it doesnt matter

jinventive (author)2007-05-28

HINT: To stop the coil from overheating, you could wrap a layer of electrical tape over each layer of wire you add :)

FrenchCrawler (author)jinventive2007-05-29

That would weaken the magnetic force created on the piece of metal and would take up a lot of extra space. And that would trap the heat for only so long before it would escape. If you wanted to put together a real electromagnet (not one that was done in a hurry), you cold use small DC fans inside of a plastic handle to draw the heat away...

sneigke (author)FrenchCrawler2008-07-16

No, it would NOT. The flux depends on the total number of turns*current. Tape simply adds some volume to the coil but will not weaken the flux generated. No offence but some of your suggestions could hurt people which is uncalled for considering you can wind a megnet which can life 100's of pounds (yes hundreds) using a single D-cell flashlight battery! how's that for major, and safe!

Javin007 (author)sneigke2010-06-10

You seem to talk alot about magic things you can do because you've "been an Electronics engineer for 25 years" but you haven't actually given any suggestions at all. Please do explain how you could "wind a megnet " that can "life 100's of pounds". If you do not have a helpful suggestion, then kindly STFU. I found this instructable to be quite interesting and helpful.

Ninth (author)sneigke2008-10-29

Can you describe how this is done?

sneigke (author)FrenchCrawler2008-07-16

besides, heat should NOT be an issue!

sneigke (author)sneigke2008-07-16

BTW, I've been an Electronics engineer for 25 years. And I know what I'm talking about.

lukeyj15 (author)2009-12-03

 AH! See, I was trying it with insulated copper wire. Shall try with stripped cat5 cable.

dciocoiu (author)2009-06-06

How can i make a 1016 Hz electromagnet?

arzarach (author)2009-06-01

Why do you have diffrent wires. I'm trying to make this for a telegraph .

thermoelectric (author)2009-01-10

How many turns of approx 48AWG wire should I use for a electromagnet that draws no more than 0.25A at 24VAC for a relay?

Which will not overheat over extended periods of time.

killer wj (author)2008-07-15

Then how do u switch the magnet on and off?

CharlieC (author)killer wj2008-12-10

Killer WJ == put a simple "ON - OFF" switch in one line between the power source and the contact.
Good Luck.


FrenchCrawler (author)2006-09-28

Quick question: How'd my instructable join the "Robotics" group? This isn't really considered robotic type stuff, is it?

ewilhelm (author)FrenchCrawler2006-09-28

Currently, all the groups are public and any group member can add any projects to a group; think of the groups as filters to show members and Instructables in a unique way. We're rethinking this and will soon have a more traditional group system: public groups, moderated groups, etc...

FrenchCrawler (author)ewilhelm2006-09-28

Thanks for the reply. I was wondering how my instructable got into their group and now I know. Now I'm off to make my last magnetic instructable (Using the electromagnet above except stronger. I'm updating on how to make the electromagnet stronger in a minute before I leave though and how to make a handle for it).

CharlieC (author)FrenchCrawler2008-12-08

Please see my notes at the top of this Blog and see if you can possibly help me? I would truly appreciate the help. THANX CharlieC

CharlieC (author)2008-11-26

Is no one on this blog anymore? I am sure from reading the other comments that someone has an answer to my problem; but no one answers. Maybe it's because we are so close to Thanksgiving. Oh well, please have a good Thanksgiving. CharlieC

FrenchCrawler (author)2007-11-25

You can use Cat 6 cable, but I suggest taking each wire out of the main casing to do the wrapping. The magnetic field will become stronger with each wrapping, but as the wrappings move further away, the effect will diminish within the wrappings themselves. To make the effect stronger you can either just increase the voltage/amperage (to a certain degree, too much and the heat generated will melt the wires. That's if you want to make a super strong magnet) or make more wrappings and increase the voltage/amperage. The area wrapped with wires won't be usable as the magnet (unless you have a thick/wide piece of metal much like industrial magnets... ex: junkyard magnet). You need to keep an area of the metal clear of the wires to be used as the magnet.

sneigke (author)FrenchCrawler2008-07-16

The VA is irrelevant. Stronger == more wire, not melt the wires with excessive current.

Do you have any electronics theory under your belt? Just curious and not meant as in insult, but your ideas are going to hurt people because basically you don't seem to have a clue as to what you're doing in a correct way.

pyro-jim (author)sneigke2008-08-22

i could ask the same question to you, increasing the amperage would increase the power of the magnet. just try it; go on, I dare you

FrenchCrawler (author)2006-09-29

Just an update. If you make a strong electromagnet and use my handle idea, don't use it for more then 10 minutes at a time (I'm really going to have to design a better handle later), otherwise the foam will heat up and start to melt in the middle. Mine was all squishy, but the ends stayed solid so it didn't leak out, it hardened back up after I allowed it to cool for awhile, but I'm just giving you all a warning now that the heat will eventually build up (even if you make a weaker magnet) enough to burn/melt stuff. Perhaps adding in something to measure the heat inside will give fair warning before anything dangerous can happen.

xxobot (author)FrenchCrawler2007-10-23

Just a comment on the heat thing... lightbulb... aka. lightbulb heats up because of the amount of juice running through it... I don't know how but perhaps less voltage more current or something

sneigke (author)xxobot2008-07-25

Both. A lightbulb is basically a tiny resistor, the filament. The light depends on the temperature and size of the filament, larger filaments making more light.

The heat given off it simply the power dissipated by the filament which - voltage across it x the current through it. The current through = the voltage / resistance of the filament.

Other types of lighting, fluorescent, and LED's, for example, use totally different methods of creating light and don't depend on heating something up to make light and are thus much more efficient.

sneigke (author)2008-07-16

Maybe you wanted to be able to switch the magnet on and then off, but lack the knowledge on how to create such a wonderful thing?

That sums it up pretty well French!

sneigke (author)2008-07-16

properly designed, the wires will not get hot and can run forever. A Large coil will inherently limit the current and will need very little current to make a strong magnet.

bigpinecone (author)2006-11-25

is there a certain current you have to have passing through it? also, is a 9-volt sufficient?

At the time I was doing this, I believe I was passing 10V through it. I'm not sure if it is 9V sufficient, I'll have to dig it up later and try it.

alright, i'll hook up another 9volt in parallel

sneigke (author)bigpinecone2008-07-16

no need, use more turns. see above comment. 1.5 volts can lift 300 pounds!

sneigke (author)FrenchCrawler2008-07-16

1.5 volts is sufficient for lifting 300 pounds. It's basic physics, not rocket science. I'd feel bad if someone got hurt doing some of the stuff you describe.

sttrboy7 (author)2007-09-16

i tried makeing an electromagnet with bare wire and it worked better than insulated wire.

sneigke (author)sttrboy72008-07-16

Not possible and a bad idea. If the turns short out, you're defeating the purpose. My write up on amp*turns, which French should know beter about, seeming failed to post.

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