In addition to simulating and verifying that the NC program produces the correct finished part, the right simulation/optimization software should enable manufacturers to build and simulate entire CNC machines in order to eliminate potentially disastrous machine crashes. A machine crash can be very expensive,

potentially ruining the machine, and delaying the entire manufacturing schedule. But by simulating the machine and machining process beforehand, the chance for error is dramatically reduced. Proving-out new programs on the machine becomes an unnecessary step saving valuable production time.

Machine simulation software should detect collisions and near-misses between all machine tool components such as axis slides, heads, turrets, rotary tables, spindles, tool changers, fixtures, workpieces and cutting tools. It also should detect near-misses between machine components to check for close calls, and also detect over-travel errors.

The virtual machine tool model used during simulation can be created by the user or it can be supplied by the software vendor. Using sample machines supplied with the software can be an excellent starting point to create nearly any specific machine configuration. Most importantly, a broad selection of CNC control configuration files should be supplied. These control files emulate the CNC control’s behavior and include various models of controls. Simulation of tool change, motion, cycles, sub-routines, macros, loops, etc. for all popular CNC controllers should be supported.

As expensive high-speed machining centers become more prevalent in the moldmaking industry, it becomes increasingly important that companies understand how to protect and get the most from their investment. There are a number of reasons why NC program simulation and optimization is important for high-speed machines and high-speed machining. For example, high-speed machines:

1) Cut between 10 and 50 times faster than conventional machines
Are very expensive

2) Use expensive and fragile cutting tools; advanced inserts, balanced cutter bodies and holders
Are extremely sensitive to feedrate errors
Are extremely sensitive to cutting volume errors (both too little and too much)

3) Must maintain optimum cutting condi-tions at all times
With high-speed machines, there is an extremely low tolerance for feedrate and spindle speed errors. By the time an operator detects an error, it is most likely too late. The nature of the machining demands that optimum cutting conditions be maintained at all times.