Special Die Casting Case Studies

Robots have many applications; they can manufacture cars, electronics, and medical devices and even automate some aspects of Chicago White Metal’s die casting process. Robots are here to stay, and one of the main reasons is that they can perform high-risk tasks that keep humans out of potential harm. An excellent example is extracting a hot casting from a steel die casting mold. They can also perform repetitive pick-and-place tasks, enhancing productivity and minimizing room for error.

Last year, Chicago White Metal integrated several more robotic work cells throughout the plant to assist with die casting, CNC machining, and other operations. CWM employs both traditional and collaborative robots. The CWM team recognized the advances in robotics technology and used them to provide its growing clients with the best products and services.

Traditional Robots

Chicago White Metal has employed traditional robots for many years. The advantage of a conventional robot is that they are very robust and can handle a heavier payload. They can also work more quickly and precisely in harsh environments than collaborative robots. They are ideal for high-volume processes. Chicago White Metal uses traditional robots in larger die casting machine cells and high-volume dedicated machining cells where additional methods, such as leak testing and visual inspection, are incorporated.

Collaborative Robots

Chicago White Metal’s R&D team researched the advantages of collaborative robots (co-bots). Since most CWM’s parts do not require a large payload, collaborative robots make sense for many of our processes. These robots are less expensive and easier to program than traditional robots. They can be deployed alongside humans to drive efficiency. They can also work autonomously in environments that may be less safe or less hospitable than other areas (e.g., CNC machine areas).

CWM employs co-bots to load/unload CNC machines, perform light-duty filing and other processing, and perform air gaging and other inspections.

Robotics Manufacturing & Die Casting

CWM uses robots to manufacture cast and machined components, and several of the components CWM manufactures are components of a robot. CWM’s die castings are used as internal or external structural components. The exterior housings protect the sensitive electronics within a robot and provide a beautiful cosmetic appearance. Internal components might hold together different CPUs, motherboards, other vital electronics, gearing, and mechanical controls. Die-cast components can be used as sensors, actuators, power supply unit encasements, control systems, wheels, and end effectors (this can range from universal grippers to mimic human hand functionality to interchangeable tools such as drills).

CWM produces components in Al, Mg, and Zn.

Robotics require components with excellent physical and mechanical properties. Some of the components are heavily loaded and need maximum strength and stiffness. Others are at the end of the arm, where a lighter-weight alloy, such as aluminum or magnesium, can improve the robot’s capabilities. Some small parts can be cast in high volume using zinc, which is excellent for lower tooling costs and longer tool life. Chicago White Metal Casting is unique because we can cast components of all three alloys within our plant. In general, the following is true:

• Using a magnesium alloy would create a lighter-weight part with stiffness equal to aluminum.
• Using a zinc alloy would work best for thin walls, tight tolerance parts, or small parts with high volume.
• Using an aluminum alloy provides an excellent overall value when weight, tolerances, corrosion resistance, and finishing options are considered.

Robotics Case Studies

Collaborative Robot Components

Alloy: A380

Processes: Initial Processes: Die cast, de-gated, polished, vibratory deburred, acid-etched, CNC machined, Trivalent Chromated (TCP), highly cosmetic powder coated in the customer’s proprietary red color.

The CWM Difference: Chicago White Metal cast eight parts on the robot (seven are visible, and one is in the interior), working closely with the customer’s engineering team throughout the prototyping and the entire design-for-manufacturing (DFM) process to create the family of parts. Certain parts required a more complex tooling design due to the odd shape of the parts, such as one of the parts requiring the part to be sawed off at the gate to prevent breakout and other trimming defects.  The result was only one minimal die casting area requiring hand cleaning.

Three-Spoke Wheel Hub for Automated Warehouse Robot

Alloy: A380

Processes: Die cast, de-gated, vibratory deburred, machined

The CWM Difference: Chicago White Metal casts a custom aluminum, three-spoked wheel hub, allowing the robot to move to various areas quickly. CWM worked with the customer’s engineering team on design, making the DFM process relatively smooth and straightforward when moving into production.

Click here to view the .PDF: Industry Spotlight – Robotics

This in-depth White Paper from the North American Die Casting Assn., offered by CWM, details how collaborative engineering between OEM engineers and custom die caster engineering can improve production efficiencies and reduce part costs. The case study method is used to discuss cost-saving opportunities for existing parts at the point of tooling replacement or required product design revisions, as well as for clean sheet designs.

For the free PDF download of this NADCA Engineering Bulletin on “Collaborative Engineering,” go to the “Engineering Bulletin” section of CWM’s Web OEM Dis Cast Design Center (one of nine resource sections with over 70 free design guides and aids). To view the PDF, click here.