Hello everyone .. I am a beginner. I just finished a cnc .. I have up to 3 motors nema 34 closed loop with drivers cl86t .. The 2 motors work perfectly x and ? except Z .. The Z axis loses steps, falls down .. I do not know the reason .. All I have checked them and they are ok .. All the screws are tight .. I do not know the other I have to do so I ask for help .. Sorry for my English.