Migration from Mach3 to QtPlasmaC + DIY THC with Arduino

Hello everyone,

I built a plasma cutting table (2500x1250mm) three years ago for my business needs, and so far, it has given me great satisfaction.For the past few weeks, I have been upgrading it because, until now, it was running in a limited way due to Mach3.
Having had some experience with LinuxCNC (EMC) several years ago, I decided to convert it using QtPlasmaC.

QtPlasmaC has allowed me, among other things, to:

• Have a real Z probing (precise and configurable)
• Implement proper plasma cutting management
• Use THC
• ...

Hardware used for this table:

• Industrial PC "Hystou" (  link  )
• 17" industrial touchscreen monitor (4:3)
• USC Board from PICO Systems (  link  )
• 4x "STEPPERONLINE" DM860T_V3.0 drivers (  link  )
• 4x stepper motors with encoders
• X and Z axis driven by ball screws (5mm pitch)
• Y axis driven by belt
• Plasma source: Hypertherm Powermax 105 SYNC

I am reaching out to share the THC system I have developed and tested over the past few days (not without some difficulties).
I am using an analog input of an Arduino UNO to measure the arc voltage, which is then sent to the PC via "USB".
A Python script retrieves the value in "real time" and creates a HAL pin that can be connected to QtPlasmaC.

I am using:

• An Arduino UNO
• An isolator/converter (  link  )

The Powermax voltage divider is set to 20:1 and connected to the input of the converter (configured for 0-20V). The converter output (set to 0-5V) is connected to the Arduino's analog input.
The Arduino sends a smoothed value every 100ms and is particularly stable.
This allows me to configure QtPlasmaC in Mode 1 (using Arc OK from the Powermax) and let QtPlasmaC precisely control the torch height.

Here are the first tests of the THC, with a sheet placed on spacers:
 

Position of the sheet during cut:


First produced part:


Another improvement I made: a cross-shaped laser pointer:


Now, I still need to fine-tune the settings, especially the axes, which are causing me a lot of trouble and failures due to the "following error.", connect the laser pointer to the controller, then, I need to restore the electrical cabinet.I will send you photos of the whole setup once it's finished.

Edit: The scripts are now as an attachment
 
 

1. Nice build and nice cuts
2. why is there a hanging 9V battery on the torch?

Hi

Thanks

The 9V battery is for the laser pointer, while waiting for it to be connected to an output of the USC controller board (the most tedious part is running the cable through the cable track).

I think it’s worthwhile for you to please post the python and arduino scripts.  It’s nice to have options, and people can learn from and possibly improve upon your work that way.  

Done