i'm building bymyself an esc.
this is the schematic: http://img18.imageshack.us/img18/2199/aresschemeesc.png
pic16f84a, do the same thing as cd4017. i'm using 60hz
i'v tested on breadboard with a ne555 as a frequency generator, R1 = 10k/ R2= 5k(POT)/ C1 = 1uF
in lower speed, bldc turns, but on higher frequencies, bldc just stop and a little noise can be heard from motor.
on pic16f84a, do the same, but, it don't pulses as cd4017, the ports are allways on deppending on coil phase.
sorry for bad english