Hello !

In this Instructable i will show you how to make a powerful electromagnet which has the lifting capacity of approximately 5KG and the design of it. Of course you can increase the capacity of the electromagnet for various applications. Industrial electromagnets can lift tonnes of weight and can be designed accordingly based on requirement.

This is going to be a short instructables and I have made a video for you for better understanding.

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I have Used materials lying around my house and only Copper wire and batteries have to be ordered. You can make this for your school project.

Step 1: Materials Required

Here are the list of materials required for this project.

1. A piece of Iron (length=4cm and dia=8mm)

2.Wood pieces/plastic sheets

3. Insulated copper wire (Magnet Wire)- 24Gauge- 28gauge

4. Wires

5. Battery / Regulated DC power supply (6V - 20V)

6.Soldering Kit(Iron,flux, Solder wire)

7.Some basic tools like Nose pliers, wire cutter, etc

8.Hot Glue Gun

9.Electrical Insulation Tape/Heat shrink tube

10. Toggle Switch

Step 2: Calculations......

This following formula computes the force between a solenoid and another piece of ferromagnetic material separated by a gap of distance g.

F = (Fm)2 μ0 A / (2 g2)

F = (N*I)2 μ0 A / (2 g2),


μ0 = 4π*10power-7

F is the force in Newtons

N is the number of turns

A is the area in length units squared

I is the current in Amps

g is the length of the gap between the solenoid and a piece of metal.

You can calculate the force exerted by the solenoid from Here.

My battery was 12 v car battery and my coil resistance was 8.7 ohm.

Using Ohm's law, the current is calculated by Voltage divided by resistance= 1.37 amp.

You can select the gauge of wire by knowing the maximum current in the coil. Higher the current, higher will be the magnetic flux.

Step 3: Make a Solenoid Core Frame

It is important to make a Strong and sturdy frame for the electromagnet. Insulating the core from magnet wire is also an important step.

1. Roll a sheet of paper on the iron bar and stick it using insulation tape. It is better to use a soft iron core.

2.Use a square wood piece and hot glue the ends.

3.You can also use plastic or acrylic sheets for the frame.

You can use any material for the frame but make sure the core is a ferromagnetic material like iron.

Step 4: Winding the Magnet Wire.

I used 26 gauge insulated copper wire.

Wind around 900-1200 turns of copper wire. It is not mandatory to wind the wires in order but make sure the layers are uniform .

Use insulation tape to secure the copper wire in place and it helps in unwinding of the coil.

Use Fire or Sand paper to remove the insulation at the end terminals of the copper wire. It is important to remove the insulation for good conductivity.

Step 5: Make the Circuit Connections

After removing the insulation connect a pair of wires for the external connections

On a piece of wood, Hammer the nails and connect the wires as shown in the images.

Use a Toggle switch to switch on/off the power supply to the electromagnet.

Select the wires according to your current and it is better to use thicker wires. Solder the wires to the switch.

Step 6: Testing the Electromagnet

I have used the 12 bike battery to test the circuit.

And I have used a pair of dumbbells to test the lifting capacity of my circuit.

You can increase the supply voltage but make sure the current through the solenoid does not exceed the limit for the gauge of wire used. (Use Ohm's law to calculate)

Increasing the supply voltage, increases the current, in turn increases the lifting capacity of the electromagnet.

Please feel free to post any doubts and quires in the comments section below.

Thank you for visiting my instructables page.

Sandesh Hegde