Jim, thanks for the feedback. That is what I am looking for in turns of setting my design priorities.
I can see where knowing the actual cut current can have value; especially in troubleshooting bad cuts. The auto reduction feature was just one of those engineering things that
could be done but as you say, maybe should be left to someone that has the time to do may hours of test cuts using different values of cut current at varying feedrates and maybe even vary the arc volts with it! If there were a neat chart out there that gave me numbers than the project would be pretty easy.
I think at this point we will focus on the Digital Current Probe as it is and leave the door partially open for the more advanced auto-set and auto-cut options sometime in the future.
The IHS is essential. The trade off of doing it every pierce versus at a set distance/ frequency, is in time. Since different material can be setup to do the method any way you want it gives the operator the flexibility to use the best method. I have a different post for thin material vs thick in the CAM program. In the thin I have it "touch-off" before every pierce. On the medium I have it touch off every 20 " of X Y movement (that is not a lot of movement when you are talking about the sum of both axis). In thick material that tends to be flat and level I have that set higher.
IHS in our MACH based system (because MACH is in charge of all three axis) is set in the G-code out of the CAM. It's actually a reference (Home) move on Z. While we could use ohmic sensing, force feedback or capacitive sensing to trip the Home input action the simple floating holder with a micro switch is drop dead simple, very reliable and easy to hookup and troubleshoot. It does require a custom torch mount but it can even be fitted with an up bias spring that lets you touch off on thin material without deforming it. I have several customers cutting 24 and thinner gauge material using Fine Cut consumables and getting good results (on painted R-panels).
By having information on the toolpath out of the control software and the current position of the Z, you can easily pickup feedrates, Z height, total travel etc that let you interact through the THC. It no longer has to be set separately to do different pierce heights, pierce delays, IHS before every pierce, and the arc volts presets for a given material. As long as the material stays flat the pierce height will be correct even without a touch-off before every pierce.
Thanks again for the feedback. There is no substitute for experience!
Tom Caudle
www.CandCNC.com