The realm of manufacturing is witnessing a significant transformation with the integration of collaborative robots, or cobots, into various processes.
In our pursuit of efficiency, we embarked on a mission to explore the speed advantages offered by cobots in MIG welding.
This experiment aimed to compare the conventional manual welding approach with the potential time savings achievable through cobot-optimized welding parameters.
The Test Setup
To conduct the comparison, we utilized the Kemppi Master M power source with Abicor Binzel robotic torch kit for both test welds.
The first run adhered to the recommended parameters from Kemppi Weld Assist, a valuable tool that assists welders in determining optimal settings based on factors such as material type, plate thickness, and weld type.
For the second run, we increased the travel speed to maximize time efficiency without compromising the quality of the weld seam.
Test Piece
Our focus centered on a T-joint fabricated from two plates of 4mm unalloyed black steel. The welding process involved a double fillet MIG weld on three identical test pieces securely positioned in a jig.
Robotic Assistant
Executing the welding tasks was the UR10e from Universal Robots equipped with SmoothTool from Smooth Robotics, showcasing the prowess of collaborative robotics in industrial applications.
Results
Recommended Parameters for Manual Welding
| Weld Speed | 375 mm/minute |
| Input | Pulse 195 amps | 9 m/min |
| Weld Length | 300 mm per part |
| Time to weld 3 pieces | 3 min 10 secs |
| Weld Throat Thickness | 5,5 mm |
Cobot-Optimized Travel Speed
| Weld Speed | 525 mm/minute |
| Input | Pulse 195 amps | 9 m/min |
| Weld Length | 300 mm per part |
| Time to weld 3 pieces | 2 min 29 secs |
| Weld Throat Thickness | 3,9 mm |
Efficiency Gains
In an 8-hour workday, the advantages of cobot-optimized parameters become even more apparent:
Cobot-Optimized Welding:
- Sets of 3 Pieces: 192 sets
- Total Items Welded: 576 items
Manual Welding with Recommended Settings:
- Sets of 3 Pieces: 152 sets
- Total Items Welded: 456 items
This translates to a remarkable 26% increase in productivity during a single 8-hour day when employing cobot-optimized parameters.
Discussion
In examining the welding outcomes, it’s evident that the manual welding run produced slightly thicker weld seams and throats, in adherence to Kemppi Weld Assist’s recommendations.
However, the throat thickness aligns with the accepted industry standard for black steel of at least 0.8 times the plate thickness, ensuring weld integrity.
Minimum accepted throat thickness: 4mm X 0,8 = 3,2mm
3,8mm > 3,2mm
Considering an 8-hour workday, our calculations assume a 100% duty cycle, implying continuous welding.
Changeover times for the next batch remain constant for both methods, minimizing any impact on the observed productivity gains from cobot-optimized parameters.
As we explore avenues for additional speed optimization in welding processes, it becomes evident that specialized features designed to ensure deep weld penetration during high-speed welding can play a pivotal role.
Technologies such as the Max Speed feature from Kemppi or the ForceArc Puls feature from EWM exemplify this approach. These innovations focus on refining the welding arc dynamics, enabling faster travel speeds without compromising penetration depth.
Incorporating such specialized welding processes has the potential to further enhance the efficiency gains witnessed in our cobot-optimized parameters experiment.
By leveraging these advanced features, manufacturers can unlock even greater productivity while maintaining the structural integrity of welds, marking a promising evolution in the landscape of industrial welding.
Conclusion
The experiment clearly shows how collaborative robots can greatly improve the efficiency of welding.
By using parameters that are optimized for cobots, manufacturers can increase production rates while still maintaining high-quality welds.
As industries increasingly adopt automation, integrating cobots into the welding process is an exciting way to achieve new levels of productivity and efficiency.
