CMM used to qualify first-item catalog parts.

In any given month, Haas Automation Inc makes some 60,000 parts for its vertical machining centers, horizontal machining centers, CNC lathes, 5-axis profiling machining centers, rotary tables, and accessories.

From Haas' 620,000 sq ft facility situated in Oxnard, CA, the company produces a staggering variety of components: parts less than 0.5" up to machine beds measuring more than 120", and weights spanning from approximately two ounces to more than 10,000 lb. Shapes range from simple rectangles to complex curved surfaces.

With that kind of product flow, George Zicker, quality assurance manager, has to maintain an arsenal of tools to verify that everything meets specifications. "Measuring a 10-ft, 5-ton casting puts a strain on any measuring device," says Mr Zicker. "And, because we're making high quality machine tools, we need every measurement to be accurate, down to a thousandth or less across all 10 ft."

In the fall of 1998, Haas set out to increase its range of coordinate measuring machines (CMMs), looking for greater capacity and throughput. Originally involving seven top CMM suppliers, the sheer size of the largest Haas components narrowed the field to two. Of those, LK Metrology Systems Inc, Brighton, MI, offered the best combination of size, speed, and ease of use, with a G90C 30.15.15, with measuring range of 120"x60"x60". The company also ordered a smaller LK MSI machine, a G900 10. 10.8 with a measuring range of 40"x40"x32".

Capacity, efficiency

"Capacity was not the only criterion, though obviously it was an important one," says Mr Zicker. "Before we set up our LK MSI, we would measure most of these castings literally by hand. This would take hours and was not very accurate, so accuracy and ease of use were major deciding points." Haas continuously engineers new products, so that Mr Zicker's department sees around 500 first articles per month, many requiring new programming for the CMM.

"We saw LK MSI as moving with the most advanced technology," adds Mr Zicker. "To some extent, we were impressed with the inherent rigidity of the ceramic spindle and guide in the head, but more important to us was the relative lightness of the arm. We feel that the less mass moving back and forth, the more accurate the measurement. The relatively low mass of the ceramic plays a part in that quick responsiveness as well.

"We have come to like LK MSI's software and machine controller interface," says Mr Zicker. "One of the most productive is the ability to edit measuring routines on the fly." Haas relies primarily on off-line programming, particularly for first articles, so that the CMM can be used to continue measuring older parts while programs are developed. While this methodology provides good production efficiencies, when it comes time to measure the new part, unless the CMM's software can efficiently handle the programming errors that sometimes occur during the early stages of program development, much time can be wasted.

"When you program off-line, you're likely to include something in your part program that isn't exactly right," Mr Zicker points out. "With other machines, we would have to go off-line, fix the flaw, and start the machine over again. With the LK MSI CMM, we can go straight to the flaw, edit it, and continue, with no need to start from the beginning. If you're half way through or more when you hit the bug, the ability to keep on going really adds up to time savings."

This on-the-fly capability has proven especially useful for parts with complex curves and for reverse engineering. Haas technicians develop a close fit based on part geometry, imported via IGES (International Geometry Exchange Standard) from 3D models in computer-aided design (CAD) geometry from design engineering. "Using IGES geometry lets us do a measurement in half a day, where before it would have taken three days to recreate the geometry in the CMM program," says Mr Zicker.

Haas continues to push the limits of the DMIS (Dimensional Measuring Interface Standard) standardized programming protocol. The LK MSI equipment at Haas is DMIS-compliant, and LK MSI, a member of the DMIS Standards Committee, is strongly behind the standard. "DMIS is a collaboration," says Mr Zicker, "so some things that we need are simply not part of the standard yet. We've found LK MSI very responsive in helping us cope with these, and with programming issues in general."

Talented technicians

Mr Zicker says that the speed of adoption of the new equipment pleases him. "I have talented people here," he says, "and they took to it pretty well." LK MSI training and ongoing support has helped them cope with changes from previous equipment, as well as in development of new code for Haas-specific needs. Haas quality assurance associates run the gamut from CMM experts to e stage users. LK MSI has worked with all levels to maximize programming skills.

"Once we got the new equipment, we began setting up a strategy for using it," says Mr Zicker. "All the parts that are more critical from the programming perspective go to the LK MSI, as well as things where on-the-fly edits might be useful, as with complex geometries."

The LK MSI equipment at Haas is fitted with automated tool changers. "They have proved to be real time savers," Mr Zicker says, "when you have a part that requires different kinds of probes. With the automated probe-changer, we're not off-line for half an hour at a time, requalifying the tool. That adds up."

Mr Zicker sums it all up: "We have been very pleased with the performance of the machines, and extremely pleased with LK MSI's responsiveness on any questions or concerns that arise. They are definitely saving us time and giving us more accurate quality assurance. Haas has invested millions in 'lights-out,' automated, flexible manufacturing systems (FIVIS) to thoroughly streamline production capabilities, and field an ever-growing line of high precision CNC products. LK is helping us do that."