Ohmic sensor triggering after arc start

[Mr.Hotwire]

I'm using one of the robot3t sensors. During the IHS it works perfectly, it wont squish aluminum foil, and maintains the right pierce height.

My problem is... as soon as the arc starts it triggers the ohmic sensor, and sets off an alarm state stopping the cut.

any suggestions?

[robertspark]

as I posted on the uccnc forum.

Install a relay which you toggle on and off as part of your touchoff sequence.

the miniTHC has this as part of its input board.
https://minithc.com/pub/MiniTHC2_EN.pdf
have a look at the top of pdf page 19

There is also a schematic on the below link which has some explanation.
http://linuxcnc.org/docs/devel/html/pla ... ic-sensing
Its not quite what you are looking for as this is for actually making an ohmic probe circuit using a switched mode power supply...... all you are after is a relay which toggles the ohmic input probe so that it will stop being triggered when the torch fires.

It is probably some HF that is triggering the ohmic probe input when the torch fires

[Mr.Hotwire]

RS,

What I see is a LOT of things, and its great that they are there, but the documentation is Mach3 Specific.

I have looked at page 19, and I have cut the trace and bridged the other one to activate the built in relay.

NOW, I have to put together a maco that will turn on the relay, that will allow me to probe using the Ohmic sensor, then turn OFF the relay so that it doesnt get any "Missfires".

More learning, and more reading. Thank you VERY much for sending me back to the manual. Its been months of me away from the machine, and only now do I have the time and need to get back to it.

Thank you again!

[Mr.Hotwire]

** UPDATE **

So, What I did was I assigned Pin 15 of the LPT to M10.1 Active high and M10.2 Active Low. I used these commands like so :

M10.1 G31 Z-50 F350 (Ohmic On / Probe Surface)

M10.2 M03 (Ohmic Off / Arc Start)

This turned the relays built into the LPT BOB on and off isolating the ohmic sensor and solved my issue with THAT... now onto the rest..

[weldguy]

Nice work guys and thanks for posting back with your solution

[Mr.Hotwire]

Anything to help! Im sure others are looking for this as well.