Optimizing Dynamic Payloads in 3D Printing Construction SCARA Robots

Printing a small ceramic vase is a delicate process, but printing a concrete structure requires an entirely different class of engineering. The equipment must manage heavy, viscous materials while maintaining precision across massive print volumes. For 3D Potter, a manufacturer of large-scale 3D ceramic and concrete printers, success relies on controlling substantial, shifting loads in extreme outdoor environments.

3D Potter designs machines that bridge the gap between prototyping and industrial construction; they can print everything from mugs to houses. Their flagship SCARA HD (a heavy-duty robotic arm system), the Mixcell System, and the Continuous Cement Mix Station are designed to operate on job sites and in large studios. The SCARA HD, in particular, presents a complex motion profile: it features a Z-axis that lifts a heavy arm and an X-axis linear track that positions the robot. As the articulating arm extends and rotates to dispense concrete, the leverage ratio changes continuously. Furthermore, the payload mass fluctuates significantly depending on the density of the material and the volume of cement currently filling the delivery hose and nozzle.

To handle these variable inertias without sacrificing print quality, 3D Potter relies on Teknic’s sophisticated servo control algorithms. Specifically, they utilize Teknic’s Inertia Matching Technology™ (IMT). This algorithm provides adaptive gain control for high-inertia and dynamically changing loads—exactly the scenario found in pumping and articulating cement. By using IMT, 3D Potter can ensure smooth, accurate motion profiles even as the mechanical leverage and fluid weight shift during a print job.

Previously, 3D Potter utilized closed-loop stepper motors but they were unsatisfied with the performance and sought a more robust solution that could handle the elements and higher power requirements of construction-grade printing. A critical factor in selecting Teknic was the ability to upgrade performance without redesigning the machine’s control architecture. The ClearPath family includes a series that accepts industry-standard step-and-direction signals, ClearPath-SD. For the SCARA HD project, ClearPath-SD served as a drop-in replacement for the previous stepper motors.

"Moving from closed-loop steppers over to Teknic’s closed-loop servos was a one-to-one change," says Greg, SCARA Production Manager at 3D Potter. "We didn't have to put in much effort [to integrate ClearPath-SD] and the machine works much better than it used to. It was definitely a needed upgrade."

Beyond the control interface, the physical integration of the ClearPath motors, combined with the IP67-rated sealing, offered distinct advantages for field-deployable machinery. Traditional servo systems often require a separate drive installed in a control cabinet, necessitating complex cabling that is vulnerable to damage on a worksite. ClearPath integrates the drive and on-body M12 connectors directly into the motor housing.

"We saw that the [ClearPath] motors were going to handle the elements better," Greg notes. “They run quite a bit cooler and have a better power system overall compared to what we were using. They're just overall more robust than the previous options we had.”

The result is a machine line that runs cooler and provides a more robust power system compared to previous iterations. However, for 3D Potter, the hardware is only half the equation. The ability to consult with Teknic’s engineering team ensures that as 3D Potter develops new, larger machines, they can optimize the motion control for every axis.

"A large benefit that you guys have given to our team is help during the development of the new products," says Greg. "In several cases, that's really saved us... you guys go above and beyond." Greg concludes, “You guys have been great to work with over the years.”