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maintaining high accuracy. For these demanding applications, Jet Edge’s Bradley Schwartz recommends a bridge-style gantry system.
“Only bridge gantries with preci- sion-ground ballscrews (dual-side direct drive) with CNC control over a fast communication system, mapped via laser at the factory, can hold high tolerances over time,” Schwartz notes. “Low-cost entry-level systems typical- ly feature a cantilever or rack-and-pin- ion design powered by a direct-drive pump or a bare-bones intensifier pump. These are not meant to be high- accuracy machines.”
Most waterjet machines are avail- able with computer-controlled taper compensation, which produces high- quality parts by eliminating the taper generated when the waterjet exits the part at a different angle than it entered.
Tip 2: Invest in Good Nesting Software
Investing in quality nesting software will help optimize edge quality, reduce waste and maximize productivity, Schwartz advises.
“Technology written into good cam software is critical,” he says. “When geometry transitions, the associated feed rate must transition as well. Ramp- ing refers to the segmenting of these transitions and inserting feed rate in steps or percentages to blend the tran- sitions. The geometry is created with- out these segments; they are added automatically by the software. This proves critical to lead-in/lead-out areas and how they blend to the entities they are entering and exiting, transitions from lines to arcs, arcs to arcs, and sharp corners, etc.”
Tip 3: Calibrate Carefully
To maintain consistent quality, have your waterjet-cutting machines recal- ibrated periodically by an experienced technician using certified laser-cali- bration equipment (such as a Renishaw telescoping ballbar system) to verify motion-system tolerance.
“Pegasus Northwest, for example,” says Schwartz, “recalibrates its cutting
machines a few times throughout the year. While calibrating a machine cali- bration typically requires a skilled tech- nician, Pegasus has trained its own inhouse technicians to do the work, and has invested in the necessary equipment.”
Tip 4: Use Quality Garnet
Quality garnet is essential to quali- ty cutting. That’s why Pegasus North-
west advertises that it uses only the highest-quality garnet.
“Using the best garnet in the indus- try allows us to cut more quickly, with optimum edge quality,” explains Pega- sus’ Dennis Pavlov.
“Garnet quality is always key,” adds Schwartz. “Once you get used to oper- ating with a certain garnet grade/qual- ity, trying to switch to a different type of garnet typically creates problems with
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