View Full Version : THC issues

04-23-2014, 11:00 PM
Proma THC, Everlast PP80s, SheetCAM, Mach3

Been trying everything over the past few days to get this to work as I'm trying to cut 18g and it lifts and warps like crazy.
Current my hardware has a Floating Head with a NO switch on it wired to the ZHome.
Proma THC activates the Z axis properly in test mode.
Using SheetCAM Post Process for "Plasma post processor for generic THC system s such as Proma Includes backlash compensation and punch marker"
Switch Offset set measured at .115" and converted and inputted into PP as mm (appr. 2.9mm if I remember)
I set the beginning Zaxis just above the plate. (everything from just touching to 1/2")

Now the problem. At the beginning of the process the torch travels down to the zero I set, not the limit switch and then travels up to infinity until I stop or I trigger my switch.

I've tried a bunch of different active high/low settings and a few other things.

Pulling hair now!!

04-24-2014, 02:09 PM
You need to use a POST (like the THC 300 or the MP1000-THC) that is setup for the auto touch off sequence...either the G28.1 or the G31 probe sequnce. The code should seek the home swtich closure (from touching the metal and moving the torch up and the g code sequence in the POST should lift it first to the top of the material (switchOffset distance) , then up the programmed Pierce Height have defined in SheetCAM, fire the torch and then plunge down to the defined Cut Height value.

Once you have it working you will be disappointed in the ability to cut the thin stuff. It's just not capable of responding or moving fast enough to keep up with warps while you cut at over 200 IPM .

The pure speed of MACH THC keeps practical response down to about 60 IPM in Z speeds on a fast Z. Factor in the added delay of the Proma that uses relays on the Up and DOWN and you will be luck to get stable operation at 30 IPM or less. Think about flying a drone at 6 ft above the ground over hilly county and your feedback is delayed by 1 sec!

The system will work on very gentle rises like on thicker material and at much lower feedrates.

10-15-2016, 06:42 PM
Could also be your voltage on the proma itself is set too high so that it keeps lifting to try and get voltage to the target area.

You can adjust the voltage on the proma on the fly to bring the Z up or down during cutting.