It Depends

 

Is the answer I dread when I ask a technical question. Unfortunately when customers ask: “How accurate can you plasma cut parts with a robot?” I reply: “It depends”.

Recently we were asked to cut 1.575″ (40mm) holes in 3/16″ plate with a circularity of +/-.005″. This is a tight tolerance for plasma. Normally we would have recommended laser cutting. But I tell people that a watt of electrons is much cheaper than a watt of photons. Plasma has a number of advantages over laser: system cost, power efficiency, maintenance costs, and safety.

So we went to the lab to explore the limits of robotic plasma cutting. What made this project unique and doable was the fact that hole position tolerances were achievable. Our challenge was hole shape and size. We used a Hypertherm XPR300 High Definition Plasma and a KUKA North America robot. Jim Walker & David Luce programmed the cut in small segments to optimize torch path and cutting parameters and cut holes +/-.005″.

BUT your part accuracy depends on many variables. In the video, I stick out my neck and QUANTIFY best, worse and typical effects of 7 issues on part dimensions. This should start an argument!

ARC Specialties thrives on problems, send us yours!