Greg your ignorance of MACH3 shows.
1. They DO support Arc Transfer. In fact there is a dedicated pin (called Torch ON) for arc good. Movement is held until a valid Arc Good signal is received. We ship a current sense transformer with every THC to allow ANY plasma unit to have that feature. Out THC Sensor card has isolated circuitry to use the current sense transfomer and feed the signal back to MACH. MACH can work with plasma units that have the signal or ones that don't.
2. The Screens in MACH3 are totally customizable. You can make DRO's the size of watermelons. You can add any button and any button image you want. The screen layout program is easy to use and free. We ship custom profiles and screens with all our units. I have done custom screens for various customers and OEM's
3. I have worked with Art at MACH and Les at SheetCAM for the last two years to put together the perfect plasma cutting environment. Those products work with our MP1000-THC Digital THC to control all of the aspects of plasma cutting. To say MACH3 is not a good platform for plasma is totally false. The fact is that it is probably the best, and supports things like Anti-Dive because the Z axis is always under control and the look ahead part of the program can integrate with the THC movements. You typically have to get into really high dollar plasma cutting systems to find where the THC is truly integrated with the motion controller software. Things like pierce height, inital cut height, lead-in/outs, feedrate, etc are part of the tool definition and post processor. SheetCAM costs $159.00 and supports all of that (and more)
4. To say MACH3 is just for steppers is once again incorrect. It is limited to step & direction output but modern servo loops are closed at the hardware layer (e.g. The motor drive). Using Geckos, Rutex, Tecknix or others the servo's are controlled by the drive (kinda like a Smart Drive?). If you strap a Gecko on the side of a servo motor you can call it a Smart Drive but it uses S&D instead of a serial protocol.
They (MACH) have recently introduced plug-in's that allow third party vendors (like me) to write interfaces for supporting products. We already have a low cost 20 function handwheel/pendant using a plug-in and have three new products that will be out before the end of the year.
Okay, lets not call it "open" source. Let's call it non-proprietary. That means I can buy replacement parts from other sources. That means if my CAM software is not doing what I want I can switch without throwing out the whole drive system. That means if I lose a motor driver I don't have to replace an entire motor. I can even change brands of one drive if I want. You keep trying to equate this to a DIY project where the builder has to make all the decisons and without your expert guidance they are destined to slog about to make it work. While we have well over a hundred DIY guys using the MACH3/SheetCAM and MP1000-THC there are more "commercial" machines out there using the same formula. The customer can rely on the vendor of a complete system to support it and to have engineered it to provide the functions they need. They also can get ideas and support from other sources if the fancy strikes them.
You analysis of stepper vs servo is flawed. Each has it's place and properly designed stepper systems coupled with modern microstepping drives don't lose position and are simplier to implement. For high speed low torque applications like plasma, steppers can be cost effective. Do I like servo's? You bet. I have several tables and I have used both (sometimes on the same machine). My production plasma table is servo (dual drive on the gantry) but has a stepper Z. To equate steppers as some old technology VS servo is misleading. Stepper motors are still being made and are better than older ones. Stepper drives are still being designed and improved.
I just got an e-mail from a PlasmaCAM user with two pages of a sad tale of frustration. They were unhappy with how the Plasmacam software worked and when they called BobCAD and asked "will your software run my machine" they were told "yes" and then sold a $850.00 package for over $3000.00. Obviously BobCad would not "run" their machine since the PlasmaCAM controller does not take native g-code; and now they can't get BobCad to do anything, the CC company won't reverse the transaction because PlasmaCAM will not make a formal statement that the software will not work with their machine, and the customers looks like they are out 3 grand.
This is not about how PlasmaCAM or DynaTorch runs their business or supports their cusomers. It's about the perils of dealing with proprietary systems.
Now that you have the Rest of the Story, I agree. Go look at both sides of the coin and don't be surprised if the shine lives on the other side.
Tom Caudle
www.CandCNC.com
www.FourhillsDesigns.com [commercial decorative plasma cutting]