Im Bulding A Custom Brushless Motor
 

Basicly, we got to build a motor for a for our physics class. We only get 1m of wire, a "D" battery, a disc magent (small rectangle, thick, not bendable), 2 paper clips, sand paper, wire stripper, masking tape. I got to make a workign motor with godo anmoutn of rpm.

-i need a single wind, but how do i actually wrap the wire around the motor paper clips (im using the paper clip as the pole).
-can some1 explain the basics behind a motor? i know tis all about magnetic fields and currents. I have taken physics so you dont have to dumb it down too mcuh.
-How do i do the motor without the brushes? lol basicly im building a brushless motor.

well the main difference between a brushed motor is that the winds are on the inside of the can and not on the armature and the magnets are on the rotor instead of the can.

uhh, anyclue on how to make one? Oh yeah, to get good grade, my grade depends on how much RPM i get outta the motor.

So, you want to build a burshless motor. And from the sounds of it, it will only be a two pole motor.

One thing you're missing is a controller. A brushed motor uses contacts to switch the polarity of the electricity going to the windings at the appropriate time to attract and then repel against a stationary magent, giving motion. The only thing a brushed ESC gives you is brake, reverse, and efficient speed control by sending high speed pulses of DC to the motor instead of pure DC. The duty cycle of the pulses (width of the "on" pulse vs the width of the "off" time) is what determines speed. The same thing could be done simply by sending a reduced voltage to the motor, but there are a lot more power losses doing this compared to the PWM control. if you only need forward motion with no speed control, you can really do away with a controller for a brushed motor since the brushes and contacts take care of switching the polarity to create motion. A brushless motor on the other hand, needs to have the switching of the polarity done at the controller; otherwise the shaft will turn a little and then lock. The controller sends a succession of PWM signals to the windings causing rotation.

If the parts you listed is all you're given, I don't think you can make a BL type of motor. A brushed motor would be much easier even though it won't be as cool. Although it's not going to be too easy because they didn't give you a whole lot of material to work with.

As far as the winding orientation. Picture wrapping a wire a number of times around a ferrite rod (in your case, a paper clip). The ends of the rod would be the N and S poles, depending on the polarity of the battery. Your permanent magnet will have N and S poles too. You just have to make it so the poles from the rod and the permanent magnet come VERY close to meeting so the lines of magnetic flux are concentrated the most, while still allowing the rod to rotate. Obviously, the wired rod will have to be on an axis (so it sorta looks like a propeller) and then you'll have to make brush contacts of some kind attached to the non-conductive axis. The ends of the windings will attach to these contacts. You can use more paper clips as the brushes, which will go to the battery.

I hope this helped and wasn't too simple for you...

It's hard to think they make you build a motor with these part's. The brushes will be very hard to make since the pole's need to be isolated. Correct me if i'm wrong but you need atleast 2 pole's to turn the rotor over. And if you do got the winding's, you need the magnet to fully surround the rotor.

In my mind i'd say no way on earth you can make a motor out of these part's. But they didn't give you this test for nothing.

Here is a hint half way down the page
http://www.ceressoft.org/Files/emotors.htm

Instructions if the hints are not helpful enough :027: http://fly.hiwaay.net/~palmer/motor.html

WEll gee nl 12. That is like cheating. I guess it is a motor though.

Now that is cool, would never thought of that myself.

Nice find nl12! That is cool! :)

Alot of my classmates are using the CIRLCE with magnet and battery. Thing is, how can i get more rpm outta the set up? Should i wrap more wire around to make the circle? like shitloads of loops, or alot less? i wonder if i coudl hok up some ball bearings on teh setup

Bearing's won't do a thing to such small motor. It will be turning slow anyway, the only way to get more rpm is a powerfull magnet and like you said less winding's ohh and more volt's.

I thought if you put more wraps together like joined at ends it would make it faster.(parrellal) It would cut down on resistance as well. May try to move it closer and see what happens. Just remember that small wire at 50k rpm may hurt if it fly out.

Make coils smaller in diameter.

Artur

If you want to go faster, use fewer winds (fewer turns), but use larger gauge wire. That's how they do it on brushed motors.