I know you can get some 6mm round rod on Amazon, (double check that it is 6mm though should be able to see what bearings go in the trans for size) and then use a vice on a drill press, you would want to get non- hardened then harden once you have the almost finished product. Get a good enough setup might be able to start selling them to people lol in my FB groups lots of people looking for foc for these.