Building a DC motor. (1 Viewer)

[physchemology90]

So I've got to build a DC motor for class and i'm not sure about a few things.

Firstly, for the commutator i was thinking of just using the wire ends, that way i dont need to build a specific split ring commutator as the wires act as the conductors and there is the gaps between them, my armature and axle arent that wide so the gap wouldn't be too large, i was just wondering if the gap in between would be likely to stop the motor running or would there be enough momentum for the motor to make it arond until the wires are connected again. That or should i put two metal sheets around to act as conductors with a larger area so more contact and less of a gap?

Secondly, how could i get the motor to start without having to give it a slight spin at the start? My friends said something about a switch but i'm not quite sure how that would work.

Any help is greatly appreciated.

 

[thehootman]

I like to call these low tech motors "paperclip motors". Basically, they work fine (that is they spin around) if the armature is balanced. If it is not balanced then the "gaps" that you mention will make the motor fail.

For a motor like this you will have to give it a little spin at the start. The only motors that dont are multi-pole ones that you will have to have a complex commutator for.

 

[tom101007]

it wont work if your comutator is simply the wires, you will need to use the sheets
unless you have the wires that are braided copper then you might be able to spread it out, (but why would you be using braided copper wire for your windings?)
so to make it short no just using 2 pieces of wire will not work for your split ring commutator