Portable CMM Helps Ice The Production Of Refrigeration Units

Business has been hot at the Carrier Transicold production facility in Athens, Georgia. With over a 50 percent market share in the truck/trailer refrigeration unit industry, this wholly-owned subsidiary of United Technologies has been in business since 1970 and continues to strengthen its leadership position every year. As is true with any growing production operation, a big part of the success-challenge is in finding ways to simultaneously improve both quality and productivity. In Carrier's case, one of the key tools in use to meet this dual objective is the Romer portable CMM.

Traditionally, Carrier has used a combination of surface plates, steel rules and angle blocks to build a 3D measurement scale for measuring each of the rack configurations. Although for many years, this was the best measurement methodology available, its shortcomings in the areas of flexibility and set-up time were a clear obstacle to improving productivity. In addition, these measurement system limitations added time and effort to the production ramp-up of each new or special-order configuration.

In August of 1994, Carrier began using a portable CMM system from Romer, Inc., of Carlsbad, California to inspect the dimensions of the various production frames. According to Mike Durban, Senior Quality Engineer at Carrier, "We chose the Romer because of its combination of portability, reach and accuracy.

To measure the 98 different datum points on a typical frame would take between eight to ten staff hours using the previous method. With the Romer six axis articulated arm's ability to instantly obtain data anywhere the human arm and hand can reach, the total measurement time has been reduced to approximately one hour. This naturally translates into a significant cost savings for the company. In addition, because of the portable CMM's flexibility, the set-up time for measuring different frames has been minimized as well.

Because of the system's user-oriented Suprastuff software, training time for new users is said to be optimized as well. In describing the learning curve for the Romer operators, Mr. Durban says, "From the time you put someone's hands on it to the time they're up and running is about one to two hours."

While the Romer was originally obtained specifically for use in taking production measurements of the refrigeration frames, as with many flexible tools various users at Carrier are already finding additional benefits of using the system. Quality engineers have begun to use the Romer to check pulley alignment and assembly fixturing and have even used the system's portability to check fixturing at suppliers' sites. Designers have used it to reverse engineer existing parts into new design databases and its ability to check out prototypes is likely to help streamline new product hands-off between the design facility and the Athens, Georgia production facility. The Romer is also being used for tube inspection, using a non-contact probe and Supravision tube inspection software.

According to Mr. Durban, "The Romer allows us to measure production attributes of completed units that could never be measured before. Alignments, fit-ups and even design issues now can be more readily quantified and evaluated in real-time."

The bottom line is what determines who is and isn't a leader and for Carrier the bottom line is improved production processes and increased quality levels.