Not all motors are half turns. I've seen Thunder Power 550 size that are 4.0 turns and 5.0 turns.

One day I was on the phone with them and asked how that is done given that the collector ring is usually in the front of the motor and the terminals in the rear (thus the half turn to get from front to rear). The guy I was talking to said he didn't know and that the guy who designed the motors was no longer with the company.

I have seen whole turn motors from other manufacturers, just don't remember exactly which ones right now.