Thanks, Greg. I measured my coupler nut, and it’s 11mm, so the 11mm nut lock is the one for me. Like my other parts, it was too tight at first, but a few minutes with a swiss file and I was able to press the coupler in with a c-clamp. It is definitely locked in place now. Thanks again!
Today I got everything put together except the z axis and the drive belts. Corner blocks, rollers, center section, legs, and stepper motors are all mounted. Woohoo! Just need to drill the z axis tubes and I should be able to start looking at the electronics. My DW660 and Ramps LCD arrived today too!