Machsupport Forum

Mach Discussion => Mach4 General Discussion => Topic started by: massynrt on June 14, 2023, 01:25:11 PM

Title: My own Plasma THC and Screen
Post by: massynrt on June 14, 2023, 01:25:11 PM
I made the switch to Mach4 for my DIY plasma cutter - And after many hours of struggling with scripts and a lot of back and forth with Trevor I got my own THC working.  I must give credit to Mach4 since a lot of the inspired code is from the original mcTHC although it all has been rewritten.

Some changes i felt needed to happen from the original mcTHC -

- THC Adjustments rate cannot be set as a % of the max federate of a motor.  This does not translate across machines.  I changed this to be a % of the current XY Blend Velocity.  The faster I cut, the faster the torch can move.  Simply physics. I have added a dynamic mode that does take the voltage difference between target and current into account and adjust the thc rate quicker or slower.

- I removed the PID as this is too complex for general Plasma Operators, but also overkill for the small changes required.  I've replaced this with a static and dynamic option.

- Sampled Voltage - When the M5 macro complete, the system will measure samples and avg a target voltage.  You can specify the delay time, and samples to use.

- I changed the modes to only 2.  Manual and Auto.   If you enable auto, the system will switch from manual when ark ok and sample voltage completed. (If used)

- Anti Dive (Based on low feedrate) is always enabled.  M62/M63 gcode to stop THC is also added.  Thus you can cut slower with THC enabled.

-I've added 3 target voltage slots - Depending on the Requested Feedrate in Gcode, the target voltage is set.

Let me know if this is something you would like to try out..


Title: Re: My own Plasma THC and Screen
Post by: Bill_O on June 14, 2023, 03:34:16 PM
Very nice.
I don't do plasma so have no idea if what you did makes it better for others.
Better for you so that is all that counts.