Prensas Schuler of Brazil has found a way to quickly write the computer numerical control (CNC) programs needed to produce press systems components, using macros and CAM software.
The company supplies advanced mechanical and hydraulic press systems for customers in the automotive industry, their suppliers and the household appliance industry.
These presses require a variety of machined components, including beds, slides, gears, moving bolsters, uprights and many others in a range of sizes and styles. For any one month, dozens of new CNC programs are needed to produce the parts which meet special customer requirements.
Writing computer numerical control (CNC) programs to produce each of these parts using traditional methods was time-consuming and expensive. Technicians had to deal with the geometrical complexity of these components, as well as special programming touches required to avoid damaging them.
Because tolerances are tight, trial cuts and touch-offs are built into the programs to provide operators with the opportunity to verify dimensions to avoid the risk of destroying the workpiece. The programs also need to include detailed annotations that serve as tool setup and machining instructions for the machine operator.
However, Prensas Schuler found it could reduce the time required for CNC programming by taking advantage of the open architecture of ESPRIT computer-aided-manufacturing software from DP Technology to write Visual Basic for Applications (VBA) macros.
The company wrote macros for each of the main types of parts used in its presses. When run, these macros prompt the programmer with questions, such as special features required, the tooling used to produce the part, as well as the dimensions for the custom part.
Once it has collected these customisation options, the macro automatically generates the CNC programs needed to produce the part. It also provides a tool list and a tool setup diagram that shows the zero point for the tooling on the part.
These macros substantially reduced the amount of time required to program new parts and also reduced the number of programming errors. It is now possible to create a CNC program for a new part in a matter of minutes compared to the hours required using traditional methods.
In addition to creating the CNC program, ESPRIT also verifies the geometry of the finished part and the integrity of the machining operation.
The software generates the toolpaths and G-code needed to machine the part, then simulates the machining operation while the programmer views each cutting tool being loaded and taking its assigned cuts along with the entire machining environment in dynamic 3D solids.
This allows the programmer to make changes if errors or mismatches are spotted during the simulation.