Developing and Designing Vacuum Grippers for Production Line Robots

The Challenge

Harvestance is a company that specializes in design and engineering services, particularly in additive manufacturing. They offer 3D printing design solutions (DfAM) and services for a variety of industries, including automotive, semiconductors, footwear, and food tech. Recently, Harvestance has received many requests to design and manufacture customized, lightweight, and strong grippers for collaborative robots used in automated production lines.

Traditional aluminum grippers are often heavy, which limits the weight of the workpieces they can lift and increases energy consumption. Harvestance's customers, such as users of collaborative robots and robot system integrators, have highlighted several issues:

• Payload Limitations:
  Collaborative robots can usually handle only small payloads, up to 20kg. Conventional aluminum grippers made by CNC machining typically weigh 1 to 2 kg or more, which takes up a significant portion of the robot's capacity and limits the weight of the workpieces it can manage.
• Customization Challenges:
  Job site conditions vary, requiring grippers to be customized. However, the complexity of geometries and conditions makes customization difficult due to the high cost and long manufacturing time of traditional methods.
• Pneumatic Gripper Issues:
  Pneumatic grippers with multiple suction cups need numerous vacuum tubes, which can interfere with the robot's movement.
• Post-processing:
  Designing custom grippers for different usage conditions is challenging while maintaining competitive pricing.

“With Markforged’s CFR 3D printing technology, we expanded our business by developing lightweight, strong robot grippers with competitive lead times and prices.”

– Seungjae Leem CEO of Harvestance

The Solution

“We were convinced that 3D printing could fully address these pain points. We chose Markforged composite 3D printing technology to reduce the gripper’s weight while improving its strength and stiffness, optimizing performance,” explains Harvestance CEO Seungjae Leem.

Harvestance initially focused on creating lightweight designs by integrating vacuum channels directly into the gripper body, allowing for one-touch fitting without the need for external tubes. They used various design techniques to enhance the quality and efficiency of 3D printed parts, such as minimizing surface roughness and designing self-supporting internal vacuum channels. This approach improved quality while reducing time and costs.

Material selection is crucial for factory production tools like grippers. Mr. Leem and his engineering team tested various printers and materials, including Fused Filament Fabrication (FFF), Stereolithography (SLA), Selective Laser Sintering (SLS), and Powder Bed Fusion (PBF). They found that only Markforged, using Onyx and Carbon Fiber Reinforcement, could meet the required flexural and impact strength for certification.

Markforged also offers superior surface quality. Unlike other 3D printers that require post-processing steps such as removing support structures, depowering, washing, curing, or polishing, Markforged parts are ready to use right off the print bed. This eliminates delays and reduces labor costs associated with post-processing.

“We chose Markforged composite 3D printing technology to reduce the gripper’s weight while improving its strength and stiffness, optimizing performance.”

– Seungjae Leem CEO of Harvestance

When Harvestance needs to print larger tools like customized grippers for palletizing or heavy pick-and-carry tools for large industrial robots, they use the Markforged FX20 industrial 3D printer. This faster printer accelerates production by three to four times, making the process more efficient.

“Utilizing Markforged 3D printing technology, we achieved an 80% weight reduction compared to standard commercial grippers and reduced delivery time from two weeks to two days, compared to conventional CNC machined grippers,” says Harvestance CEO Seungjae Leem.

By reinforcing the bottom of the gripper body with continuous carbon fiber and glass fiber, Harvestance created a strong, light gripper capable of supporting heavy workpieces without altering its shape.

“The impact of stalled production was significant, costing tens of thousands of dollars of product output on the tannery a day,” Armstrong recalls.

"Markforged’s high-strength material (Onyx), Continuous Fiber Reinforcement, excellent surface finish, and easy post-processing have been ideal solutions for us. Our engineers can focus entirely on their work, developing products without concerns about mechanical properties, post-processing burden, or quality,” added Leem.

“Utilizing Markforged 3D printing technology, we achieved an 80% weight reduction compared to commercial grippers and reduced delivery time from two weeks to two days, compared to conventional CNC machined gripper.”

– Seungjae Leem CEO of Harvestance

The Future

Harvestance is using its expertise in mechanical design and DfAM solutions, combined with Markforged composite 3D printing technology, to create a new line of grippers that are lightweight, strong, customizable, and affordable.

Currently, they're offering personalized robot gripper services to meet the unique needs of each customer. Their long-term objective is to provide a service that rapidly delivers customized parts tailored to individual customer requirements, regardless of location or time constraints. As a first step, they've developed an algorithm to automatically design customized grippers and are developing an online platform where customers can design, order, and pay for these grippers. This initiative will soon expand to include products like finger grippers and gripper tips.

In addition to streamlining the design process, Harvestance aims to automate production systems by using the Markforged Digital Forge platform for parts ordered through their online 3D printing service platform.

“Markforged’s technology and the easy production process have been crucial in starting and expanding our robot End-Of-Arm Tooling business. We believe that the Digital Forge platform will enable us to further streamline and modernize our operations in the future.”

– Seungjae Leem CEO of Harvestance