In-House and Cost-Competitive

Recently, transportation costs, quality problems and logistics issues have led many users of offshored components to re-examine their supply policies. As a result, some parts that were being sourced in low-labor-cost countries are now coming back to the U.S.

Helping to accelerate that trend is Acme Manufacturing Co. (Auburn Hills, MI). The company says its affordable robotic polishing/deburring systems provide an alternative to low-cost offshore labor for a variety of parts.

The latest addition to the line is a high-production, dual-arm system aimed at finishing of aluminum die-cast components. According to Acme, high-volume, lower-cost products such as die castings that require finishing have been prime candidates for offshoring to lower-wage markets. With simple teach pendant programming and low-maintenance design, the company's automated lets U.S. finishers and manufacturers cost-competitively do the work themselves—and avoid potential quality and supply issues.

Acme says conveyors and other part handling and queuing options can provide reliable hours of unattended processing time for users. For small to medium-size parts fixtured in trays, a simple dual-drawer arrangement allows one tray to be loaded with parts by an operator while the robot unloads, finishes and loads parts from another tray in a second drawer adjacent to the first. The drawers pull open directly from the cell enclosure, and use of two drawers creates a queued part reserve for continuous, uninterrupted production.

According to the company, switching from manual to robotic polishing/deburring also has other benefits. Users can achieve up to 6× longer media life as a result of contact efficiency (time on the part), constant work pressure, cycle time repeatability and part path programming capability. Flexible, automatic force control and variable-speed spindle motors optimize finishing head compliance (response and reaction) to suit the operation.

Robots used in the systems are supplied by Fanuc Robotics America Inc. (Rochester Hills, MI). Acme says Fanuc's off-line programming and simulation speeds robot program development and increases up-time of the finishing system. Users can quickly create and verify programs for complex parts and shapes, and temperature monitoring allows automatic process modification to reduce the effects of excess heat resulting from mechanical finishing operations.

Automatic media wear compensation software ensures consistent performance throughout the life of belts and buff wheels by adjusting cell process parameters (such as cutting rate and force) to match the performance and lifespan of the media. Media life management software can provide up to five times longer belt life than conventional polishing/deburring.

Robotic finishing systems can also use integrated vision capability to identify parts and verify positioning, ensuring that parts are properly loaded before pick-up by the robot. Under development are laser/vision applications said to provide 100% dimensional part inspection. Acme says this capability has the potential to provide closed-loop feedback to the robot for modifying process parameters such as force control and contact time on the finishing belt or wheel.

Other available system features include:

Universal tooling concepts that can reduce system design, build and operating costs.
Online diagnostics and documentation said to minimize maintenance time and costs.
Internet-based trouble-shooting capability with Ethernet host support.
Media life management and control.

Acme says robotic polishing/deburring can cut costs enough to avoid offshoring of many parts or bring some offshored jobs back. In one case, a U.S. foundry exploring offshoring at the request of a customer calculated that the cost to produce a cast part in the U.S. was $0.51 using manual labor. The cost to produce the part in China—including shipping—was $0.13. Using robotic automation to increase deflashing production by 140%, cost per part decreased to $0.08—an 84% reduction in the customer's costs.