The Benefits of Tool Monitoring
With millions of manufacturing jobs going overseas to cheap labor countries, companies today are struggling to keep part costs competitive. The machining industry has had to look for various ways to reduce the cost of the parts being machined. One of the most popular ways to reduce part cost is lights-out, or unattended, machining.
This was the goal of Glendinning Marine Products, Inc. (Conway, South Carolina), a manufacturer of EEC and cable retrieval systems. After the acquisition of a company that produced cables and other components for large companies such as Mercury and Bombardier, GMP found itself contracting out a majority of its high quantity jobs to other machine shops. This was because the two CNC lathes the company had were busy trying to keep up with the demand for its products. Owner Paul Glendinning’s goal was to bring the high quantity work back in-house but in a way that was the most cost-effective. After some research, the company purchased a CNC lathe with a subspindle and a magazine-style bar feeder for unattended machining. “We liked the shorter setup times associated with the CNC compared to a screw machine, and the long runs that we were able to obtain with the bar feeder,” says CNC programmer Mike Gasque.
After considerable success, the company came across an obstacle that threatened its goal. The spring-type ejector system on the subspindle wasn’t completely ejecting the parts when running pieces more than 4 inches in length. “During the part transfer, the part in the subspindle would hit the part on the main spindle and bend the rod, jam the ejector, break the cutoff insert and sometimes warp the blade,” says Mr. Gasque. “The downtime and tooling replacement costs associated with the crash were costing us at least $100 each time it happened. It got to the point that an operator had to be at the machine at all times to prevent a crash and would have to stop it if he had to leave at the end of his shift. We needed help.”
Help came in the form of TPS International, Inc. (Sussex, Wisconsin) and Steve Pechloff (sales manager/mechanical engineer). “We had read an article that Steve had written about tool monitoring and how their systems could be used for object and/or free space checking, and we felt as though we should give them a call to see if they could help,” says Mr. Gasque. “Steve was very helpful and explained how using one of these systems would benefit our company. We decided that a PCS-100 was the one we needed. The price was justifiable, and with the sealed sensing head, it seemed bulletproof. We purchased it. ”
“After we installed the unit and set it up for free space checking, we realized how good our decision had been. We had been running a particularly long part and were having all sorts of trouble with it,” says Mr. Gasque. “Over an 8-hour shift on that day, the machine hung up ten times. The PCS-100 prevented a crash each time. With each crash costing us at least $100, it more than paid for itself that day.”
For free space monitoring, the PCS system can be used in reverse logic, where an unobstructed space is allowed to be the accepted condition while an obstructed space will generate a fault. This feature is useful for part ejection, especially for CNC lathes with a subspindle.
Eight months after installation at Glendinning, the PCS-100 is still going strong and has prevented countless crashes. “We have not had any problems at all with this system,” says Mr. Gasque. “It has performed flawlessly, and beyond our wildest expectations. We have recently purchased another CNC lathe and barfeeder, and we are planning to install two PCS-100s on it—one for checking part ejection and one checking for tool breakage.” The company also has four horizontal and two vertical CNC machining centers. “I feel like we will probably be installing tool sensors on all of our machines in the near future,” says Mr. Gasque. “Not only will the quality of our parts be better, our tooling and labor costs will drop. This means an overall decrease in the cost of the part.
“Our goal is to be able to leave all ten machines running, and know that when we return the next day, the TPS sensors will have done their job,” he concludes. “It’s a no-brainer. Our only regret is that we didn’t purchase one sooner.”