Machine Condition and Safety Factors

Two machines of the same model, one maintained and one not, do not accept the same NC program. The simulation models the cut, not the wear state of the machine running it, so the machine's condition enters through the safety factors — and setting them honestly is the difference between an optimized program that runs and one that only runs in simulation.

The Simulation Is Valid Only Under Stable Machining

Every availability ratio HiNC reports — yield stress, spindle torque, spindle power, thermal yield — is a fraction of what the cut is allowed to demand. The results describe reality only while all of them stay under 100%. Above that the machine is no longer doing what the model says it is doing: the spindle droops, the feed per tooth rises, and the divergence grows rather than staying proportional.

Reading those ratios, and what each one means at 100%, is Evaluating Process Machinability.

Safety Factors Are Where the Machine's Condition Goes

HiNC exposes a safety factor per limiting quantity — spindle power, spindle torque, thermal yield — and they feed straight into the optimizer's output. They are not decoration: raising a factor lowers the feed the optimizer is willing to assign, across the whole program.

Use them to describe the machine you actually have. A machine in poor condition should be given larger factors, or a lower preferred cutting force, so that the optimized program leaves it more headroom. The same program optimized for a well-maintained machine will be faster, and will be the wrong program for the worn one.

See Also

• Spindle Capability — the curves the power and torque factors are applied to
• Chatter, and What the Simulation Does About It — the failure mode the force ceiling exists to avoid, and the two cases it does not cover
• Cutting Force and Torque Validation — a worked maximum feed rate, and where the safety factor enters it