I’m having a similar issue with the ZX Axis on my new MK2 48x30, but only headed away from the motor (traveling right) during the last 50% of travel. Rapid travel back to X0 had no unexpected noise.
I’ve tracked it down to the anti-backlash nut as well. If I loosen it, I barely get any noise heading out but obviously there’s a lot of X-axis slop. Everything is square, the v-wheels are adjusted correctly, I’ve applied graphite to the lead screw, and I’ve bumped the gantry into the rails.
I ended up positioning the gantry about 25% away, tightening down the anti-backlash nut and barely engaging the “backlash adjustment bolt”. This eliminated 90% of the noise in Rapid movement and it doesn’t bind at all.
If someone has any other suggestions, please let me know. Unless I put a fixture out there, I probably won’t be cutting at that distance often but I want to make sure I’m not missing something that will bite me later.
Thanks!