The cost of making your own set must have been many times more than the cost of buying one. What is so unusual about your situation that required it and what length of cranks did you get?
There was a thread around here a while back about a guy that makes very short cranks so that folks with knee mobility issues can continue to ride. The fellow that started it also claimed that it was surprisingly effective. Not a lot of torque but easy to spin at a much higher than normal cadence to make up for the lack of torque. The short arms were done by simply drilling the arms and spot facing the drill points and then threading the arms. The excess being then cut off and the end re-profiled.