Hypertherm Inc., Hanover, N.H., manufactures advanced plasma cutting systems for a variety of industries. For more information, visit www.hypertherm.com.
Rapid Part Cuts Cycle Times
New technology maximizes the time the plasma torch is actually cutting metal.
Watching a traditional plasma cutting operation reveals that a considerable percentage of the machine’s total cycle is non-cutting time—time spent moving from one cut to the next. Rapid Part technology can deliver up to a 100 percent increase in productivity through cut-to-cut cycle time reductions achieved without operator intervention. By maximizing the time the torch is actually cutting metal, Rapid Part minimizes inefficiency and operating cost.
For a typical plasma cutting machine, cut-to-cut cycle time is the sum of all necessary movements between cuts and may be segmented into four primary components: torch retract, table motion, initial height sensing and gas pre-flow.
With a typical plasma setup, when a cut is completed, the torch retracts from the plate by several inches. After moving to the next pierce location, the torch then performs an initial height sense and goes on to pre-flow the gases for piercing. When timed, this commonly adds up to six or seven seconds for each cut-to-cut cycle, which can quickly accumulate to a significant amount of non-value-added time each day.
Working with the right software, Rapid Part technology reduces cycle times in several ways. Based on part geometry, it minimizes the distance between the end of one cut and the pierce on the next part. Rather than fully retracting after each pierce, the torch travels closer to the plate at high speed and transitions to slow speed and optimum pierce height automatically. Intelligent retract features set it at the correct height for the next pierce, based on material and part properties.
The system also minimizes the chance of torch collisions and unnecessary torch Z-axis motion by applying optimized avoidance paths, enabling partial or full torch raises. If Initial Height Sensing is deactivated, gas pre-flows during traverse, eliminating idle time at each pierce. The torch is designed to fire quickly using rapid ignition technology, which eliminates long purge cycles.
The most significant productivity gains can be achieved on nests using thin plate with a high quantity of parts or pierces. The more pierces there are on a given plate, the greater the time savings.