How to build a simple AC motor with Styrofoam

In summary, the conversation revolved around building an AC motor using styrofoam, magnets, screws, and magnet wire for a physics class project. The individual had already built a cylinder with magnets and a wooden stick for rotation, as well as a ring of styrofoam with screws and wire wrapped around them. They had questions about wrapping the bolts counterclockwise and clockwise, getting an AC current, and using a commutator with aluminum wrapped around a stick. The conversation also included suggestions for making the project work and anticipation for the results.
  • #1
alexia-m
1
0
Hello everyone,

For my physics class, I want to build an AC motor with styrofoam, magnets, screws and magnet wire.

So far, I have built a cylinder of about 2.5" of radius and 1" in height with eight magnets (strengh 6/10) around it. Each magnet is glued on the side of the cylinder alternatively north, south, north, ... .
This cylinder is crossed by a wooden stick that allows it to rotate.

I also built a ring of styrofoam that goes around the cylinder. Across each magnet on the outer ring, I have eight screws with wire magnet wrapped around them (150 turns each).

Should I wrap the bolts alternatively counterclockwise and clockwise or does that matter?

Also, I heard that I need to have AC current going through it (I have tried with a 9V battery in the past which didn't make the system rotate). How can I get an AC current going through it?

I also tried to light a small LED light by connecting the magnet wires around one bolt to the led light and forcing the center wheel to turn. The light did NOT turn on. How can I make it light up? If I connect all the coils in series, would that work?

My teacher said that there was a way to make a commutator with aluminum wrapped around a stick and cut on one side. How would that work?

Please, let me know if you have any idea to make this project work.

I would greatly appreciate it!

Thank you.

Alexia-m
 

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  • #2
How can I get an AC current going through it?
Hook it up to an AC voltage source?
My teacher said that there was a way to make a commutator with aluminum wrapped around a stick and cut on one side. How would that work?
It would allow you to apply current for only half a turn.
The principle is the same as: http://www.electronicsinfoline.com/Projects/Science/Physics/Electricity_and_Magnetism/make_a_simple_electric_motor.shtml [Broken]
... only, there, the insulation has been filed off half the circumference of the wire.
 
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  • #3
alexia-m said:
My teacher said that there was a way to make a commutator with aluminum wrapped around a stick and cut on one side. How would that work?

Did you try a Google search on something like "motor commutator"?

http://www.google.com/#hl=en&tbo=d&sclient=psy-ab&q=motor+commutator
 
  • #4
"Should I wrap the bolts alternatively counterclockwise and clockwise or does that matter?"

Yes you should, since your magnets are arranged with alternating polarities. It does matter.

"Also, I heard that I need to have AC current going through it"

You heard correctly. If you use d.c. the rotor will just lock in one place. With a.c., once you've spun the rotor up to a fast enough speed by hand, it should continue to rotate as a 'synchronous motor'. Its rotation frequency will be a submultiple (depending on the number of poles) of the a.c. frequency.

"My teacher said that there was a way to make a commutator with aluminum wrapped around a stick and cut on one side. How would that work?"

It wouldn't work for your motor, because the rotor has the permanent magnets and the coils are in the 'stator' (stationary bit).
 
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  • #5
It wouldn't work for your motor, because the rotor has the permanent magnets and the coils are in the 'stator' (stationary bit).
The axle is an insulator right?

Put foil around half the circumference of part of the axle, use two brushes ... one is wired to the power supply and the other to the coil. This will break the circuit for half the cycle.
 
  • #6
Simon. There are several coils spaced around the stator circumference.
 
  • #7
Four coils and eight magnets, equally spaced ... yes I saw. The magnets are alternating N-S, everything has nice tidy symmetry. The half-period on half off thing was just an example fo how to do timing, not recommended timing for this particular design. How to design the motor is OPs job, surely?

The point: Positioning conducting strips around the axle can still time the current to the coils however you want (effectively phase-locks a square wave to the rotor) ... this motor will work using a commutator and you don't have to crank it up first.
 
  • #8
"How to design the motor is OPs job, surely?"

Yes indeed.
 
  • #9
Alexia-m: PLease report back on how you get on.
 
  • #10
Alexia-m: PLease report back on how you get on.
Second that!
I love these projects - students come up with stuff I'd never think of so I am on tenterhooks to see what you do.
 

1. How does an AC motor work?

An AC motor works by using alternating current (AC) to create a rotating magnetic field. This field interacts with the motor's stator and rotor, causing the rotor to rotate and generate mechanical energy.

2. What materials do I need to build a simple AC motor with Styrofoam?

To build a simple AC motor with Styrofoam, you will need a Styrofoam cup, copper wire, a battery, a magnet, and some basic tools such as scissors and tape.

3. What are the steps to building a simple AC motor with Styrofoam?

The steps to building a simple AC motor with Styrofoam include cutting a coil of wire, attaching the wire to a battery, creating a magnet with a nail and a magnet, attaching the magnet to the Styrofoam cup, and connecting the wire to the magnet to create a rotating magnetic field.

4. How can I make my AC motor more efficient?

To make your AC motor more efficient, you can use a stronger magnet, increase the number of coils in the wire, or adjust the spacing between the magnet and the wire. Additionally, you can use a larger battery or a different type of battery with higher voltage.

5. Can I use this AC motor for practical purposes?

A simple AC motor made with Styrofoam may not be powerful enough for practical purposes, but it can be a fun and educational project. However, with some modifications and additional components, it is possible to build a more powerful and practical AC motor using the same principles.

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