A form-compensation option has been launched by NUM for its Numroto tool-grinding software.

The option enables tool manufacturers to ‘close the loop’ between CNC tool grinding and measurement, further increasing process accuracy and consistency. NUM’s system inherently compensates for process variables, such as temperature fluctuations and grinding wheel wear, and is likely to prove popular with manufacturers of specialist precision tools, which demand tight production tolerances.
Machine shops seeking to maximise the accuracy of tools produced on CNC grinding machines generally use a CMM to obtain probed measurements of the machined part; using this information to influence the production process during subsequent machining operations. Until now, Numroto users processed CMM results with proprietary third-party compensation software running on an external computer, before feeding a suitably corrected target profile back to the CNC machine.
Designed in conjunction with several key Numroto end users, NUM’s form-compensation facility is a fully integrated part of the company’s form-cutter package, and completely dispenses with the need for any third-party software. The data exchange between the CMM and CNC machine can be handled by XML interface, or by export/import of the DXF file via a local area network (LAN).
The software employs filtering algorithms to create a smooth and precise compensation profile. Importantly, the orientation of the grinding wheel and the path speed from the original profile is always calculated so that only the position of the contact point on the cutting edge is compensated – and not the orientation of the grinding wheel. Performing the calculation in this way ensures that the surface quality of the tool is unaffected by the compensation. The form-compensation option is compatible with Numroto version 4.1.2 or later.
For further information www.num.com