Get a grip: Automation & Robotics

For many unique operations at machine shops, custom grippers are the only solution. But implementing them isn’t as easy as simply buying and installing a piece of machinery. There’s a certain level of nuance. Creating custom grippers entails a wide range of considerations and plenty of best practices to abide by.

Some gripper-makers sell standard grippers, and some build one-off solutions for each client. Schunk Intec Inc. in Morrisville, North Carolina, does both. The company specializes in clamping and gripping technologies and has a machining group and an automation group. The machining team makes toolholders, lathe chucks and vises. The automation side focuses on custom grippers that attach to the end of robotic arms.

Catalog parts are used as the exoskeleton for Schunk Intec’s system. Within that, a lot of customization is done for clients.

Some shops might consider buying strictly off-the-shelf components to handle parts.

“While the gripper itself may be a standard catalog item,” said Business Development Manager R.J. Ruberti, “it usually requires a set of custom-designed fingers to match the part.”

For that reason, he implores shops to “work with a company that understands the intricacies of the application.”

By Design

Ruberti said there are potential pitfalls when designing custom grippers. These complications can be designed around but only if the gripper-maker has enough knowledge and experience in the space. This is because the process of designing grippers is very difficult.

A standard Flex Grip Tool connects two work-handling arms. Image courtesy of Schunk Intec

The method of manufacturing grippers varies from client to client. The usual starting point is to gather information about the operations and needs of a customer before forming a comprehensive 3D model of the existing arrangements. From there, gripping solutions are proposed, feedback is sought from the client, and a consensus is reached.

Although a gripper-maker relies on its industry-specific knowledge and experience, it can’t complete a project without client input. Personalized solutions necessitate an understanding of customer needs. The only way for that to happen is through communication with a client about constraints, wants and requirements.

For machinists to get the best results, they should know their processes and come prepared. Ruberti recommends understanding the parameters, metrics and information about an operation before reaching out to a custom gripper company. While the company might be an authority on the subject, the company won’t know client operations until they’re discussed, and the final product will be highly customized.

If a shop provides sufficient insight upfront, the final product should integrate smoothly. The overall turnaround time also will be much quicker, effectively saving time and money for the shop. When a customer doesn’t know things like the weight and the range of sizes of the materials in a process, the customer can get a gripping solution that simply doesn’t work.

Options

Although grippers might use standard parts, most are viable for only certain weights, sizes, orientations, positions and so forth. There is no one-size-fits-all solution for handling materials.

In addition to knowing the physical parameters, Ruberti urges machinists to think about the contamination that grippers might come into contact with. While coolant and chips might not mean much to a
machinist, their presence could completely change the design for a custom gripper.