# 04 MyPlasm CNC - Plasma OHMIC and Floating Head - Step by step

[@konvickajan7242]

Hello guys, is there any tip how to make ohmic shield much more reliable when there is metal dust and splashing water? I've tried add to circuit (ohmic shield) a 20K potentiometer and it is better but still unreliable. Is ohmic shield "only for dry cutting"??

[@Krishell]

use a "pipe" as shield. and blow air for a couple of seconds when Z going down. (if you have good airflow and starts when its 15-10mm over the part, it cleans the surface 99% of the times. ). some people use air while cutting also (if water is a problem). search for " Cnc plasma tips" on KZbin,. I found this tips in a boring long video. some young us guy(

[@made-by-dad]

Thx😊👌

[@kevinmason8374]

im looking for advice on how to set the overall zero position. (the grey numbers next to when you reset your own zero's to start your project) any advice on where to find these settings please?

[@myplasmcncsystemen1506]

It's machine coordinators , it's zeroing during References / Homing

[@made-by-dad]

🙏