If you have been wondering what it takes to build a CNC Plasma Cutter then get ready to look no further. [Desert Fabworks] has documented the trials and tribulations of their CNC Plasma Cutter build. Saying it is extremely detailed would be an understatement. They cover everything from choosing components to machine setup.
The group already had a CNC Plasma Cutter that they have outgrown. To justify the new purchase the replacement machine would have to have a few non-negotiable features: 4×8 ft cutting area, torch height control, water table, cutting up to 1/2″ steel and be easy to operate and maintain. For the frame and gantry, they settled on a Precision Plasma kit as they felt it was the best value that met their requirements. The electronics package was separate from the frame kit and was provided by CandCNC. Among other things, this package included the power supply, stepper motors, stepper drivers and the torch height controller. For the plasma cutter itself [Desert Fabworks] chose a Hypertherm Powermax65 which can cut up to an inch thick of mild steel and has swappable torches so the main unit can be used for both the CNC table and hand cuts.
One of the more interesting (and maybe overlooked) parts of the build process was the custom cart that holds the controls, computer, monitor and plasma cutter. The lid of the cart flips up and exposes the computer monitor mounted to the underside of the lid. The keyboard and mouse reside on a pull-out tray. And to make the cart match the machine, it was powder coated blue.
The assembly wasn’t all rainbows and sunshine. A few weeks into using the machine they noticed the X and Y axes were out of square. After replacing a suspect component didn’t fix the problem they decide to physically align the gantry. They started by strapping a pen to the torch mount and drawing right angles on a piece of paper. These lines were then compared to a square. When the direction of misalignment was identified the bolts holding the gantry together were loosened, the gantry adjusted by hand, then the bolts were re-tightened. The same drawing test determined if the adjustment was acceptable or not. As you would expect, it took several tries to get the gantry lined up using this method.