I've had a few machined parts that had mfg problems, maybe the bolt holes are supposed to be counter sunk on FT12? Mine are not, and a 40mm m3 bolt isn't quite long enough to make contact with the threads on the stepper motor as shown on "X Assembly Step 10". I see there's 2 more 45mm m3 bolts. I can't see that they are to be used anywhere else, but they are a little bit long. I'm going to have to go buy some m3 washers.