Plasmcam Question

[DaFischQC]

Plasmacam DHC table
Thermal Dynamics Cutmaster 80XL

I'm cutting 14 gauge pieces quite often and it's going fairly well..BUT...
Once in a while randomly when the torch picks up and goes to the next path to cut, it will not go all the way back down to cut height and it just "sprays" or blows plasma down at the table, but doesn't obviously cut as it's not close enough. If I stop, re-initialize, and try the same path again, it will drop down and do what it's supposed to do and continue on...until it may do it again later in the piece. Clean, nice bare metal, new consumables..doesn't matter.
I don't get it and it's driving me nuts! Could it be the Z axis screw has a bur or something in it preventing travel? I can't "see" that..but I can't get the screw all the way out either..just the cap at the top to check it. It doesn't feel perfectly smooth traveling, but no different than it did when this problem didn't happen..if that makes sense.
Any ideas?
Thanks guys (and gals)

[jimcolt]

The DHC uses z axis motor torque sensing to detemine when it finds the surface of the plate. If there is a bind in the movement of your z axis slide or leadscrew....it will increase the torque and make the system think it has found the plate surface. I would remove the z axis motor an inspect the lead screw carefully....also move the slide up and down and closely inspect the bearings.

Jim Colt

[DaFischQC]

Thanks for the input Jim..Now if I could just figure out how to get it all apart. I'll see what I can do and report back to you asap. Thanks again!
Kevin

[DaFischQC]

THANK YOOOOOOU JIM! Got it cleaned up and it hasn't hummed that nice in a long time! Thanks so much for the advice and info!