How Does Partial Wire Insulation Affect Beakman's Electric Motor Functionality?

[KLscilevothma]

http://fly.hiwaay.net/~palmer/motor.html

In step 2, it says

On one tail, use fine sandpaper to completely remove the insulation from the wire. Leave about 1/4" of insulation on the end and where the wire meets to coil. On the other tail, lay the coil down flat and lightly sand off the insulation from the top half of the wire only. Again, leave 1/4" of full insulation on the end and where the wire meets the coil.

Why we should remove the insulation from one side of the wire while to sand off the insulation from the top half of the other end of the wire? What if we remove all the insulation from both ends of the wire? And what happen if we remove all the insulation of the wire?

By Flemming's left hand rule, we can work out the polarity of the magnet used.

I've made this motor before, it's easy to make, and pretty cool!

 

[J-Man]

Originally posted by KL Kam
Why we should remove the insulation from one side of the wire while to sand off the insulation from the top half of the other end of the wire? What if we remove all the insulation from both ends of the wire? And what happen if we remove all the insulation of the wire?

The reason to entirely remove the insulation from one side of the wire is so that it is always in contact with the battery (through the paperclip).
The reason to remove 1/2 the insulation from the other side of the wire is so the coil (electromagnet) is only on, or active, 1/2 the time. This way you can get the coil-magnet and ceramic-magnet to "push" against each other without them "pulling" each other 1/2 the time, which would keep the coil from spinning.
Remember if a north-pole end of a magnet is near a north-pole end, it will repel, but if a north-pole end is near a south-pole end it will attract. If we have equal "pulling" and "pushing", the forces will cancel each other out. If we only do one or the other, there is no other force to cancel.

 

[KLscilevothma]

got it! Thank you