Surface Measurement Of Round Parts Helps Manufacturer Grow

A small manufacturer can grow its business the same way that a large company goes about the task—by leveraging quality programs and quality technology to win new business and grow existing accounts.

Lou-Rich, Inc., is an Albert Lea, Minnesota, contract manufacturer that makes products for industries ranging from agricultural, food processing, lumber and medical, to name a few. A robust quality assurance program to grow the business includes tactics ranging from quality improvement teams, to strategically planned capital expenditures.

Team Excellence, for example, is designed to achieve high standards by reviewing processes to reduce defects per million and ensure best-possible manufacturing practices. Lou-Rich also is working to achieve ISO 9001 certification in order to maintain performance excellence and has been recommended for ISO 9001 registration.

Upgrades to Lou-Rich manufacturing systems and processes are guided by an emphasis on leveraging the latest technology to expand their capabilities.

Lou-Rich invested in a Zeiss/TSK Rondcom to conduct roundness and form inspections. The Rondcom decision was a long-range investment opportunity that emerged when the company received a manufacturing contract to build cylinder steering housings. The customer had manufactured the part in-house until it realized that an outsourcing partner could handle the job more cost-effectively. Lou-Rich was that partner, but needed an inspection system that could measure the round part accurately and rapidly. Because of the part shape and function, accurate machining and inspection are critical. The part houses several other components, and tolerances as tight as 0.0003 inch is required to meet specifications.

Since adding the Rondcom, Lou-Rich has increased its inspection and analysis versatility, identified manufacturing improvement opportunities, and added a significant source of new revenue.

"The Rondcom was truly an investment, not just a purchase," said Steve Seberson, Lou-Rich quality assurance supervisor. "And it really was customer driven. In the past, we used a dial indicator to check run-out on some parts, but that didn't provide the range of capabilities we needed."

When he made comparative evaluations, Mr. Seberson found alternatives lacking in versatility and capability. "Other form inspection systems can only measure roundness or flatness. To meet the requirements for long-range capital investments, we need a system that is flexible, offers a range of features and is easy to use. The Rondcom measures roundness, perpendicularity, concentricity and coaxiality."

Since purchasing the new system, Lou-Rich has found multiple ways to leverage its expanded form measurement capability. Operators conduct inspections on a variety of additional parts, including quills used for vehicle axles, and freezer tubes found in ice machines.

Dial indicators cannot measure concentricity—the inside and outside diameters at the same height in the Z axis—to find a common center. So the capability to measure concentricity is a welcome feature. To make coaxiality measurements, however, operators must first determine the datum axis.

A datum axis is established by measuring separate circles near the bottom and top of the datum hole. The computer automatically establishes a datum axis based on the two center points of the inside diameters. Finally, the operators determines the center point of the outside diameter, which will be compared to the datum axis.

Strengthening its form measurement ability also helped Lou-Rich identify a manufacturing issue that the company did not know was a problem: surface irregularities. "Certain parts need to be clamped during manufacturing, which can leave indentations in the shape," noted Mr. Seberson. "The Rondcom enabled us to identify parts being clamped too tightly, which causes the surface to be uneven."

Surface inspections also enables Lou-Rich to monitor and analyze tool wear. First article, in-process and final inspection are performed on all product runs. Operators use the Rondcom to analyze tool wear by searching for trends in parts that are not meeting specifications. If a product is falling out of spec at a certain point after several in-process inspections, manufacturing is alerted to check grinding and clamping tools for wear.

These steps take and average of 30 seconds to conduct, which indicates progress in removing complexity that can get in the way of using technology to its full potential. In roundness measurement, the centering and leveling process clearly is critical. But if the process is time-consuming and difficult-to-learn, accuracy and throughput are at risk.

Aron Bishop, a Rondcom operator for Lou-Rich, confirmed the system's ease-of-use. "Fifty percent of my learning came from simply using the system on the job and finding out first-hand how easy it is to get the results we need."