CAD/CAM slashes programming time.

CAD/CAM slashes programming time

Integrated CAD/CAM technology based on low-cost PCs is helping a sensor-system maker produce an exceptionally large and expanding group of parts. Initially, NC programming time was cut 50 percent by switching from manual to computer-aided programming using XL/NC software from PMX Inc, Livonia, MI. An additional 75-percent reduction was achieved by integrating the XL/NC programming system with PC-based CAD software. Half of that further reduction was achieved by electronic transfer of geometrical part data from the CAD system, thus avoiding data re-entry. Automatic-sequencing and path-generation features provided an additional 25 percent time savings compared to traditional computer-aided programming methods.

GSE Inc, Farmington Hills, MI, makes physical-measurement systems, based on load cells, torque sensors, and special-purpose transducers. Much of sensor production involves metal removal. "Our basic line consists of 1500 different sensor designs, the bulk of which are specials built for OEMs," says Ralph Shoberg, GSE president. "With an unending array of customer required modifications, we have to design at least a few new parts every week."

Because of many common geometries - bending beams, torque tubes, stress sections, and load-zone designs - their part mix is well suited to CAD/CAM technology. A typical part is a 7"-dia, 1"-thick biaxial load cell of hardened alloy tool steel. It has close tolerances, a complex network of thin webs, and is used to measure rubber-tire conformity.

It was designed on Cadkey CAD software running on an IBM PC. Shoberg admits that parts like this take a bit longer to design with CAD than on paper, but dramatic savings are achieved when they are modified or when NC programs are written. Cadkey generates an IGES (initial graphics exchange specification) file that totally defines product geometric entities and XL/NC programming software automatically resequences the IGES geometry file into the correct sequence for machining. According to Shoberg, the automatic re-sequencing feature has eliminated the path generation that consumed about 25 percent of the original computer-aided programming. The programmer merely selects tools, speeds, and feeds.

Another feature that reduces programming time is a prompting/language interface that guides the user yet allows access to high-level language and powerful routines for generating complex programs. Routines include true arc curve fairing, shift, scale, rotate, and mirror macros; live-screen nesting for optimum part arrangement; automatic generation of gear profiles; symmetrical part generation; groove roughing; lathe roughing; and zigzag pocketing.

For more information, PMX Inc, 33129 Schoolcraft, Livonia, MI 48150 or circle 303. 2102