I would think 2 heads would be used on a waterjet because of the slow cutting speed. The lasers cut faster and to me that would make a second head less useful. There have been double head lasers in the past but they never seemed to have caught on. It's really dependent on the parts you need to cut, it would help with small parts but as soon as you get to parts about 25 % of raw material dimensions you run into nesting problems. ie with one head you can usually get better material utilization.
2 heads on a laser might be useful for sheet cutting with N2 or Shop air and if you are an OEM with the machine dedicated to those jobs and parts. Waterjets are ideal for 2 head applications because of smaller parts distance and shorter lead ins. You can squeeze your nests together for optimal material usage. My concern with 2 heads cutting at the same time on plate is material warping. My feelings on this is that the plate will heat up faster with 2 heads cutting in to it. Kris, most water jets do come with two heads for large production runs, but you are spot on with most people who own them running only one. Mainly because they are jobs shops and large runs that would require two heads are not as abundant. Oh....Don't break Jerusha's waterjet, she'll get really pissed!
-HR this maybe my last posting....the 23rd is the end.
