Over the past three decades, Parsons Company has been recognized as a premier metal fabricator, providing components and sub-assemblies for manufacturers of heavy-duty earth-moving, mining, agricultural, forestry and materials handling equipment.
To complement its manufacturing equipment inventory, the company operates three conventional coordinate measuring machines, a Portage 350, a Shelton Checkmate and a Brown & Sharpe VALIDATOR. The company recently added a Brown & Sharpe GAGE 2000 A portable arm CMM to its complement of measuring machines, and at the same time included a retrofit of its three existing machines with PC-DMIS™ measurement and inspection software and an off-line programming station.
Variety Is the Spice of Production
Parsons Company processes about 1,200 jobs per month, generally supplying low volume, quick turnaround runs of fabricated metal parts that can range in size from small brackets to large weldments. Some of the jobs are repeats, but most are new, according to Mike Troncin, Sales Manager.
"Each part goes through what we call fab inspection after it comes off our laser cutting machines, then it's inspected again after welding, before it goes to paint and assembly," he said. "The diversity of parts and the frequency of inspection require a large number of part programs," he said. "Operators would often have to program the CMMs on the spot to handle a job, adding time to the inspection operation. "A common software program and off-line programming seemed to be the answer to improving the efficiency of our inspection operations."
Alan Knobeloch, Parsons Manufacturing Quality Manager, said the idea to retrofit the three CMMs at Parsons developed when the company began looking for a portable arm CMM to complement its inspection capability.
"A customer told us about the advantages of using a portable arm measuring machine. Many of our fabricated assemblies are large, heavy and cumbersome and don't fit on the table of any of our CMMs," he said. "The portable arm CMM allows us to take the inspection machine to the part."
Brown & Sharpe was one of the vendors contacted by Parsons management. Brown & Sharpe demonstrated the GAGE 2000 A, an articulated arm coordinate measuring system designed for portable use.
The GAGE 2000 A has a measuring range of 4' through 12'. Its counterbalanced, articulated arm allows complete flexibility and unrestricted positioning around workpieces. An ergonomically designed pistol grip gives operators full, single hand control over arm movement.
The GAGE 2000 A can be attached to virtually any surface including rolling instrument stands, part surfaces, fixtures, or tables for true portability without loss of accuracy.
"The GAGE 2000 A was equipped with PC-DMIS software," Knobeloch said. "We felt that the software would give us the capability and flexibility we needed for our inspection operations, and if we could retrofit them to our existing machines we could postpone buying a new machine."
Putting Software to Work
Parsons purchased a retrofit package for its three machines, the GAGE 2000 A and an off-line programming station for PC-DMIS. Initially, the company installed PC-DMIS version 3.0865, which has been upgraded to version 3.2.
PC-DMIS is an interactive graphics measurement software that can be linked to virtually any CMM and CAD system. It uses the WINDOWS™ operating system and offers built-in analytical reporting capabilities and intelligence that automatically names features as they are measured.
PC-DMIS V3.2 introduces DIRECT-CAD™ Interface to such programs as CATIA, Unigraphics, PRO/Engineer, SDRC, and the common CAD format, ACIS. Direct CAD interface eliminates the need for the software to translate the original CAD model in any way, assuring that accurate design data is used for part programming. Users can create part programs directly on the CAD model, reducing programming time and improving accuracy.
The integrated graphics reporting function in PC-DMIS has been improved to make it easier for users to create and automatically position dimension boxes on the screen. A graphical layout tool allows "drag-and-drop" editing so that text, charts, documents, logos, and bit mapped images can be included in reports.
This latest version of PC-DMIS builds upon the customizable graphic user interface (GUI) introduced in V3.0. Iconized tool bars help streamline and simplify operation. For example, the Custom Tools Icon Bar provides a "one click" start routine for probe qualifications, part alignments and hyper reporting functions. Other tool bars include Construction Tools, Dimension Tools, Sheet Metal Tools, and an icon group that represents the auto feature recognition function. The tool bars can be floated anywhere on the screen or can be docked against any screen edge.
Using the new 3D animation capability in the software's full machine kinematics, programmers can include elements such as digitized images of parts and fixtures on the machine so that operators can visually verify the setup and program prior to actual part inspection. In addition, the programmer can insert special visual tutorials to help explain to the operator how to run a particularly complex job.
PC-DMIS V3.2 software includes Interactive Hyper Reporting, allowing a new flexibility in not only report formatting, but in data handling as well. The deviation of individual data points can be graphically displayed along with a text description. Since individual points can be stored and retrieved, Interactive Hyper Reporting allows users to analyze features in any combination of points or features, and graphically view the result. Revised or new part programs can be written from generated data.
"We're not using all of the advanced features of the software now, but we're gradually working them into the operation," Knobeloch said.
In the off-line programming mode, PC-DMIS creates a computer-simulated CMM environment allowing an operator to develop and debug a part program using a CAD input file. These part programs can be executed using PC-DMIS on-line.
In the off-line programming operation, part models are downloaded from the company's AUTOCAD or PRO/Engineer CAD databases. From that model, the part program is created.
"Off-line programming not only improved inspection throughput, it also helped reduce operating costs as well," Knobeloch said. "We've only had to hire an off-line programmer rather than several experienced CMM programmer/operators."
Handling Data Effectively
Parsons Company also uses DATAPAGE statistical analysis software with the PC-DMIS retrofit. DATAPAGE allows Parsons management to monitor, verify, analyze, chart and graphically display dimensional data in a variety of formats.
"For every job we run, we save the dimensional data to DATAPAGE on our network," Knobeloch said. "It has been a big time saver, since our inspectors were spending a half hour to an hour recording inspection results. Now it's done automatically and we have an electronic record that we can easily reference."
The stored data is also used to prepare customer reports. "One of our customers requires an inspection report each time we produce a new product for them, use a new process or make an engineering change. Sometimes we have to FAX the report at the same time we ship the parts," Knobeloch said.
"There is an SPC requirement as well, and we've had a difficult time analyzing data because of our short runs. DATAPAGE will be helping in this area, too," he added.
At Parsons Company, common measurement and inspection software, coupled with an off-line programming station, has helped reduce inspection time and increased throughput.
"One of the biggest benefits is the consistency in which our parts are inspected. Whether at the CMMs or off-line, everyone is following the same programming procedures, Knobeloch said. "Especially with repeat jobs, we are confident no matter which machine or which inspector the part will get checked the correct/same way every time. Brown & Sharpe has enabled us to be confident that we have consistently reliable measurement data."
Brown & Sharpe, Inc.