Farason Corporation Application Spotlight: Mechanical Gripper with Custom Collar

For over thirty years, Farason Corporation has designed and delivered custom automation and robotics systems to manufacturers, shipping over 900 machines to North America, Asia, South America and Europe. The Farason team added Markforged 3D printers to boost design and production opportunities, aligned with Farason’s commitment to delivering one-of-a-kind solutions that are closely tailored to specific challenges their customers face. The Farason Corporation team created a mechanical gripper with a custom collar for a robotics packaging automation application.

The automation design involved a robot arm with a two-way mechanical gripper to grab the neck of a plastic bucket, matching onto the thread area and locating it. Then lifting the bucket, swinging it into position, and dumping the contents into the next stage of product sorting.

The initial design of the gripper started with the 3D model of jaws to lock around the neck of the target collector transport bucket, including features to match the threading incorporated into the underside of the jaws. When testing the tooling, however, they saw opportunities to increase its performance and success.

The proof of principle prototype worked to grab the bucket and present it to the robot to dump the contents, but they discovered that they were losing a couple of bags between the mouth of the bucket and the funnel of the receiver receptacle.

"We are able to iterate these quickly, adding this custom collar flange that helps contain the bags,” Design Support Engineer, Christian Weder said. “That would typically be an impossible feature.” He explained that fabricating the shape quickly in an appropriately light and rugged material wouldn’t be an option without the Markforged 3D printers, especially for the low quantities involved with creating such tailored solutions.

Once the design was set, they had one more stage to prepare the production-ready final parts. The designer of the project, Richard Cook, R&D Support Engineer for Farason, pointed out that the proof of principle prototypes in Onyx worked for testing, but even with a strong base material, 3D printing it alone wasn’t the right approach. “They would be too rubbery,” Richard said, “Between the cantilever and the length of the part, you’re holding all that massive material out there on a tiny pad with tiny bolts into the gripper mechanism itself.” The part would be solved by adding Markforged’s continuous fiber reinforcement.

The Farason team used Markforged X7 printers with continuous fiber to execute the production parts ready to send to the customer. “We were able to use just a couple of layers of the carbon fiber to prove to the team that this is the right material,” Richard said. “Support under the screws, adding washer plates to clamp the thing down, and carbon fiber running out the length of the finger to keep it stable and strong so it doesn’t twist. We printed off a set of them, and the team was absolutely happy with them.” The resulting EOAT was a hit with the customer as well: tough enough to permit a slight bend to smooth out the movement and locating, and rigid enough to do what it needed to do.

Markforged Advantages

• Cheaper parts, delivered in hours not days.
• Achieve complex features (the asymmetrical collar funnel) that could not be fabricated on-site affordably.
• 3D printing allows the team to optimize additively manufactured production solutions while testing.
• Continuous fiber reinforcement allows strength where it is needed, while keeping the part light, rugged, and suited to the deployment.