With metal-cutting machinery, on average, the spindle should be in-cut 70 percent of the available in-cycle time. However, based on a survey from more than 100 U.S. manufacturing plants (both small and large), the average Vertical Machining Center (VMC) spindle utilization during in-cut time is only 34 percent. Meaning that out of that 70 percent pie slice when the spindle should be utilized, 66 percent of the time the spindle is waiting or idle.
This low spindle utilization rate is due to the fact that manufacturers are experiencing much slower cutting results than what’s realistically achievable with today’s technology. Often this is caused by the limits of current operations, tooling or machines and, subsequently, manufacturers are spending the majority of “cutting” time doing anything but. The bulk of spindle utilization time is being consumed with setup, loading/unloading workpieces, cutting tool maintenance, chip clearing, etc.