How can I test if Ohmic sensing is working?

[BrooklynBravest]

Hey guys,

Running wright CNC next gen series table and its been awesome so far but im not sure the Ohmic sensing is functioning?

The table always diverts to floating head and today it gave me some issues. I had a 1/4" plate warped like 1/8" in the corner and the torch would punch the plate down, lift back up and end up colliding on pierce because it rebounded after being pressed down by the floating head.

I turned off floating head in the MyPlasm software, and it still did the same. I was hoping ohmic would allow it to just touch the plate and do what it had to do.

THC works perfectly I just don't think ohmic is functioning.

Setup is

Wright CNC next gen series.
Hypertherm 45xp
MyPlasm software/electronics
Grounding clip attached to slat grid (it doesn't reach the material its a short cable)

Thanks!

[djreiswig]

Not familiar with the program, but if there is a screen where you can watch inputs, you should be able to touch the clip to the torch tip and see an input trigger.
It could also be that your Z feedrate on the probe move is too fast causing it to overshoot when it touches the plate.

[acourtjester]

As djreiswig said there should be a indicator which shows when the Ohmic sensor is working. I always wire mine to the Probe input and the Post Processor should also have the probe command active (G31) for the G-code to look for the probe input. Also you need to have the probe input enabled and the input pin set. Look at you G-code for either a G28 or G31, G28 is for the floating head and G31 is for the probe. This command is always before the pierce operation so easy to fine.
on the diagnostic page the probe indicator is the "Digitize" light, when the probe is activated the Digitize with show red.

[East German]

Did you use the test function in the configuration !? It is important that the Z = 0 key is pressed before each cut!
It works fine for me. The burner image also shows the probing in red!

Peter

[schenkl]

I have a Wright Next Gen 2x4 plasma CNC. I took delivery just as the pandemic hit, so I have no one to pester with my questions....I got the table together and working....But how do I set up Ohmic sensing? I bought a cup with a side clip, hooked the wire coming from the torch mount and connected it to the control box. But what do I do with the alligator clip coming from the control box? And, as questioned, how do I know if it is working.

Any guidance is gratefully appreciated!

[acourtjester]

That may be the connection to the metal you are cutting, The ohmic sensor works when the tip of the torch touches the metal surface. Also to use it you need commands in the G-code to look for the signal that comes from the torch touching the metal. It is to stop the torch from moving down and then retract it to a location (normally the pierce height) then continue on with the g-code to start the cutting operation.
If there is an indicator for the ohmic sensor you can manually connect a wire to the torch tip and touch it to that alligator clip to see if the indicator lights.