simple DC motors help

[Eggroll451]

The design I am building is like the simple DC motor design on http://www.coolmagnetman.com/magdcmot.htm
I need some help in understanding how the shape of the loop of current carrying wire (like the difference between a square and circle shape) figures into determining the rpm on a simple dc electric motor
and also how flux and induced emf with relationship to back emf, and commutators figure into the construction of dc electric motors
and also how to maximize rpm of the spinning wire by changing such factors as shape of the wire
Thanks

[Dr.D]

What you are saying is that you need a full discussion of electrical machines. I suggest that you get an electrical machines textbook, such as Fitzgerald and Kingsley, and read a few chapters. Your questions indicate that you are starting from zero, and you really need to get quite a few basics before you set out to build a machine. Good luck!