Re: CNC Plasma purchase advice?
Well somebody from Australia should say something!
For starters, it does not sound like you have got $150k for a table from ART so Rick will be happy! They have a background in routers before they built plasma machines, they are therefore pretty heavy so are slow with acceleration which is OK if you have one of their machines cutting 30mm plate in a shipyard all day.
The Aussie market is dominated by Chinese machines with very poor controllers and often no way to accurately probe to find the material height. I would try and stay clear of them.
The other alternative is to consider building your own but you need a large skill set and the electronics has many gotchas on the design. The best plasma controller in that DIY class is Linuxcnc based on mesa hardware for the emotion control and torch voltage reading to allow Linuxcnc to manage the Torch Height control internally using Linuxcnc's sophisticated PID based algorithms.By going with an open source solution you end up with a system you are not locked into and you end up with better support from a global community more or less 24/7.
I have quoted building a complete table which would provide better performance than the options you are considering but its still going to be > $30k excluding the plasma cutter and air supply and dryer. If you want to explore this option, or part of it, feel free to PM me. You will get a very carefully engineered solution.
Finally, a note on plasma cutters. Hypertherm are by far and away the best option for air plasma. If you go with Linuxcnc, you can control them from the Linuxcnc controller using the Hypertherm RS485 interface. If you only have single phase, you are restricted to the 45XP but it does have a low duty cycle. If you have 3 phase, a 65 or 85 amp machine is a better option...
If you are anywhere near Brisbane, I'm happy for you to check out my plasma table.
Rod Webster
www.vehiclemods.net.au