I had some problems with my PWM using the 5 volt 5 amp power supplies. My PWM was rated at 12-40 Volts. When I hooked it up to a 12 volt power supply everything worked great and I can get some real slow speeds. You need to be careful with the positive and negative for the PWM as it will damage them.
Find the position you want and drill a 1/8 hole all the way through the connector and PVC pipe. Inset a # 6 finish nail and the joint will not move. Take the nail out and the joint will come apart for storage. I mark the joints with a sharpie so assemble goes faster the next year.