I need some help with building an electromagnetic motor!?
1. Is the armature wound with 2 separate pieces of wire, or one together?
2. How many ends of the wire from the armature (one or two) should be put in contact with the brushes.
Please help!
Answer:
1. The armature is wound with 1 piece of wire. Be sure to have both sides wound in the same direction.
2. Both ends of the wire. There's one bit of wire on the armature.
Other things to check..
1. You are using enamel insulated wire.
2. You scraped/sanded off the insulation at the ends of the armature wire that form the commutator.
3. The armature can swing freely when its not powered on.
4. The posts are wound opposite directions to each other.
Wierd things.
1. The posts are vertical. Normally you would orient them horizontally. You could replace them with one or two strong magnets that are readily available today.
2. The text says to wind the posts the same way. The current flows through the posts the same way so the top ends of the two posts posts will be the same polarity. The ends of the armature will be opposite polarity. You want the posts to repel or attract the armature when the brushes conact (depends on where around the tube you attach the commutator wires/brushes). Logically you want the posts to be of opposite polarity to each other, to have the same effect (pushing or pulling) on the ends of the armature that are near each post. So this guidance sounds bogus to me.
If you want to build a really simple motor, try this.. http://fly.hiwaay.net/~palmer/motor.html... I built it and it works well.
The armature winding should be a single wire running from the commutator, round both sides of the nail wound in the same direction, and back to the other side of the commutator. The idea behind the glass tube is to get low friction - your tape replacement may be causing too much of it.
The point of the brushes is to get the current flowing in the right direction dependant on the orientation of the armature (AKA rotor, because it rotates. The fixed windings are AKA the stator). If your motor is obviously pulling the rotor ends towards the stator, but then getting stuck, then you should turn the commutator (i.e. move the wires) by 90 degrees and try again. This particular design only gives contact between the brushes and commutator very briefly, so depends on the inertia of the turning rotor; you will have to spin it to get it started. A real motor has cylindrical arcs for commutator segments and at least three poles to avoid having a dead spot.
The answers post by the user, for information only, FunQA.com does not guarantee the right.
More Questions and Answers: