Machining

Delcams Software PowerMill has given us the ability to machine components in the shortest possible time. This is an issue of ever increasing importance. Any development in engineering which can give faster delivery, and at the same time improve quality, must, therefore be given serious consideration by the toolmaker.

For many years Delcam has kept us at the leading edge in the development of High Speed Machining (HSM) strategies. These use various techniques to provide rapid production of high quality machined parts. There are many aspects to be applied to the efficiency of High Speed Machining incorporating; the cutting tool, the CNC machine, the material being cut and also the use of a high quality CAM system.

Most recent developments in cutting tool technology have changed the way Cnc programmers approach jobs. This new technology in tooling has completely different Cutting characteristics to conventional tooling.

PowerMill leads the way with its approaches to efficient area clearance. The main requirement for these cutter paths are to keep the load on the cutter as constant as possible and minimizing sudden changes in cutting direction. The best strategy in which to achieve these conditions is to use offset machining as against the more traditional method of the raster approach.

Automatic Trochoidal Machining: A new combination roughing strategy has been introduced that combines offset roughing with trochoidal machining. This automatically avoids high-load cuts that could occur with conventional offset strategies, by switching to a trochoidal motion when the cutter encounters large amounts of material. Using a shaving action to remove material in these areas reduces the load on the tool to a constant level allowing faster machining strategies to be achieved.

Rest Roughing is achieved by using the previous roughing strategy as a reference file thus removing only the material left behind by the larger cutter thus reducing milling times.

Powermills high speed machining strategies result in smooth consistent cutting conditions ensuring rapid material removal and excellent surface finish. Constant Z finishing cuts at constant Z levels with an option to lead in and out between levels thus eliminating “dwell” marks. This strategy has the benefit of been able to cut in a continuous spiral if desired.

The 3d Offset finishing strategy also gives an excellent surface finish because the step over is constant regardless of the contour of the surface. Once again Spiral offset finishing will prevent “dwell” marks as the tool stays in contact with the surface model being machined in a smooth spiraling pattern.

The optimized constant Z will provide consistent tool loading, it will use 3d offset milling on the flatter areas and Z level finishing on steeper form thus avoiding sudden changes in direction.