Tormach CEO Daniel Rogge and machinist Jason Pulvermacher shared insights into the design and operation of the ZA6 industrial robot grippers used in their IMTS automation demo. This project focused on manufacturing a motor mount for the microARC 6 using Tormach’s 1500MX CNC mill and ZA6 robot. With the motor mount's unique handling requirements, the Tormach team engineered a custom gripper system for the ZA6 to tackle the challenges of flipping and securing the part as it moved through various machining stages.
Building the Initial ZA6 Gripper Design
The primary gripper designed for this project was a two-finger, parallel-jaw pneumatic gripper. Jason’s design included 3D-printed tooling plates and studs for easy adjustments and secure handling. These tooling plates featured staggered holes, which allowed the gripper’s fingers to adjust for both the raw workpiece and the finished part. By aligning the range of the gripper, the gripper could seamlessly handle parts in both their unprocessed and partially machined forms.
A critical challenge emerged with the flipping move, which required the gripper to rotate the part halfway through the machining process. As the microARC 6 motor mount was considerably larger than the soft jaws previously used in demos, Tormach had to innovate a new approach to handling the workpiece’s evolving geometry.
Finger grippers used to handle the machined microARC 6 motor mount.
Addressing the Flipping Challenge with Secondary Grippers
The team designed a secondary gripper to aid in the flipping process, which was a much more complex move given the mount's size and shape. Drawing inspiration from the setup they used at the Automate demonstration, Jason created a finger system that adapted to the specific geometry of the motor mount. This finger design featured an indent that could slot into the circular pocket of the partially machined part, helping to position it securely.
To provide additional stability, Jason incorporated rubber feet on the gripper fingers. These adjustable rubber feet allowed for fine-tuning the grip, adding friction and making it easier to lock the part into place. This simple but effective solution reduced the chance of the part slipping or sagging during the flipping motion, maintaining precision through the machining process.
Leveraging 3D Printing for Rapid Prototyping and Durability Testing
The gripper fingers were 3D printed to test the functionality before machining them from aluminum. The 3D-printed prototypes provided valuable insights into the design and allowed the team to make quick adjustments. Interestingly, the printed grippers performed so well that they continued to use them without transitioning to metal. The high-quality filament used for the 3D prints proved durable, withstanding hundreds of cycles with minimal wear.
3D printing offered the team flexibility in material choice, with the potential for even greater durability by using carbon- or glass-filled filaments. This approach also minimized project costs and time, as they didn’t need to invest in metal fabrication. The result was a reliable, lightweight gripper that performed exceptionally well for the repetitive part handling required at IMTS.
Gripper Adjustments: Ensuring a Secure Fit
In the design, Jason carefully considered the part's shape and machining requirements. He added a chamfered incline on the gripper to align with the circular pocket, ensuring the part would lock into place as the gripper closed. The additional rubber foot feature contributed to stability and friction, making the gripper hold even more effective.
This adjustable rubber foot design offers flexibility by letting the operator fine-tune the grip for different part geometries. The threaded rubber feet make it easy to adjust the pressure on the part, providing optimal stability and ensuring that the part doesn’t shift mid-operation.
3-D printed grippers used for the IMTS demo.
3D Printing’s Role in Ongoing Production
After the success of the 3D-printed grippers during testing, the team chose to use them for the entire IMTS run. Even with extended use, the grippers showed no signs of significant wear, reinforcing the viability of 3D-printed components in demanding industrial applications. Jason suggested that with further optimization, these 3D-printed grippers could be used in even higher volumes, especially with higher-grade filaments.
This outcome emphasizes the value of 3D printing in prototyping and low- to mid-volume production. By using 3D-printed grippers, the team could streamline the setup process, maintain reliable part handling, and reduce production costs without sacrificing quality.
Using Existing Features to Simplify Complex Moves
Tormach’s gripper setup for the ZA6 robot showcases how simple adjustments and strategic design can overcome challenges in part handling. By using existing features on the workpiece, such as circular pockets and rubber feet for additional friction, the Tormach team created a robust and adaptable gripper system that maintained the precision needed throughout the motor mount’s machining.
The demonstration is a reminder of how custom tooling, combined with thoughtful design and prototyping, can make complex automation tasks much more manageable. For those interested in creating or customizing gripper designs, consider the potential of 3D printing and feature-based alignment strategies.
