In machining-center setup applications, a spindle-probe system will locate the workpiece at specified data points and provide automatic input of work coordinate positions. During part changeovers, probing makes it possible to take one fixture and set up off the machine, put another one on, and get quick validation to start machining. Benefits usually include a substantial reduction in setup time, and increases in machine-tool productivity or overall throughput.

In in-process applications, the spindle or turret probing system measures critical machined dimensions to make sure they conform to spec. Most often, the inspection is combined with data feedback for automatic tool compensation. This provides process control that is especially cost-effective in turning operations. Sometimes, measurement of particular dimensions serves to provide final part inspection right on the machine.

Using this cost-analysis chart for computing potential savings that can be achieved by using a probe for part setup on machining centers. We then created a sample cost-analysis based on a hypothetical, but representative, scenario. In this example, the shop is taking 60 minutes to set up a part manually. The shop does ten setups a month, which take ten hours of shop time at $80 an hour. The shop rate per month is therefore $800 - and per year, $9600.

By using the spindle-probe system, the shop is able to reduce setup time per part to five minutes. The same ten setups now take 50 minutes of shop time per month at the same $80 an hour. With the probe, the shop rate per month is only $67 - and per year, $800.

This amounts to a savings of $8800 a year. Because the entire cost of the probe system for this application is about $6500, the investment will be paid off in about eight months and still yield a savings of $2300 in the first year alone.