My Nomad Pro recently started to have a bit of a backlash on the Z axis (0.5mm I would say).
I can clearly see the spindle and spindle motor assembly move when I apply a light force onto them.
I have recently used the machine to carve some metal (aluminium, brass, mild steel). I went slowly and used lubricant when machining steel, or when G-Wizard told me so.
Doing mostly 2D projects, it is not such a big problem for the moment.
But what do you think is causing the problem ? Wear ? Loose bolts and nuts ?