The OCM algorithm takes conventional ideas for trochoidal milling, traditionally used to achieve high material removal rates when slotting, and considerably expands the range of application. In addition to the roughing of any open or closed pocket or island, the software offers cycles for finishing the floors and side walls.
The milling tool's wrap angle can be limited to reduce heat generation and prolong cutter life. As cutting forces are lower, delicate and thin-walled parts can be machined with greater accuracy, and even spindles with low power and torque can be used successfully. Moreover, as the milling cutter occupies less of the area of a slot or pocket during machining, the accumulation and re-cutting of chips is minimised. This factor is particularly important for features that are deep in comparison with their width.
The control automatically calculates the best tool paths for maintaining constant cutting parameters. Subsequent machining operations run with continuously optimised cutting values, resulting in increased speed and a noticeable reduction in tool wear. A sample part produced recently in Germany showed the effectiveness of the latest milling strategy. OCM lowered the machining time and raised tool life by a factor of three, compared with conventional milling strategies.
Newly devised grinding control capabilities have also been added to the TNC640. The CNC was already able to control the milling and turning of components in a single set-up on prismatic machining platforms. However, grinding capabilities are increasingly being added to extend the scope of one-hit production. At MACH 2020, Heidenhain will show for the first time in the UK that this metal-cutting process can also be programmed conversationally, and controlled.
Having milling, turning and grinding on a single machine offers many benefits, particularly for quality-critical production such as mould making and medical prosthetics. These industries can now machine parts to high surface quality in a single clamping. The newly developed TNC functions enable the jig grinding of any contour, while easy-to-use standard dressing cycles can true grinding wheels inside the machine. Optimised tool management for each process supports the user.
Heidenhain to showcase conversational programming of trochoidal milling and jig grinding at MACH 2020
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Heidenhain has incorporated newly developed software into its TNC control systems that allows complex trochoidal milling routines to be programmed conversationally on the shop floor, without having to download the cycles from a CADCAM station. The OCM (optimised contour milling) functionality, which is a new option available for the company's TNC640, TNC 620 and TNC 320 CNC systems, will be demonstrated for the first time in the UK at MACH 2020 (Birmingham NEC, 202-4 April) in hall 6, stand 275.
