It stops when you stop fiddling around with toy kits and buy something designed by an electrical engineer and pay him for his time and effort.
Personally I can't see a crank welded that many times lasting more than a few hours before coming apart, best case scenario.
Audi turned 90 degree V8 cranks into 180 degree cranks by heating and twisting production blanks before grinding and finishing. I doubt you'd have much success with that method, without masses of trial and error and a well built jig to twist them.
I think, realistically, the only way you'll pull this off is with CAD and CNC. Its not as expensive as you might think, but still way too much money to spend on a K motor.