Having resolved my issue with squaring the frame I was looking at the Z Nut lock (11mm) that I have printed.
Would it be better to have both of the clamping screws on the same side? It looks to me like the one that is on the corner away from the open side of the coupler really isn’t going to do much as far as clamping down on the nut(s). The one that is on the open side of the coupler does clamp down on the long nut but the bottom end where the 5/16" nut and spring goes doesn’t have anything that is pulling it tight.
Or am I looking at it incorrectly, or it doesn’t make any difference if the bottom end isn’t clamping down that tightly?
Just thought I’d ask before I get to the point of assembling the Z Axis parts, etc.