Successful Conversion from Manual to Robotic Welding
by Rich Shive
Panasonic Factory Solutions Company
Productivity Welding Inc. (PWI), a systems integrator, reveals how to successfully convert from manual to robotic welding. A chief design requirement was achieving true dimensional repeatability.
Designing for true dimensional repeatability was the key in converting to a robotic welding system. There were a series of steps involved: weldment component and weld joint repeatability, weldment fixtures and tooling, and system feasibility and cost justification.
How to determine true dimensional repeatability:
- Choose the three to six key weldments with the greatest potential for improving welding cycle time.
- Collect a representative sample of these weldments from a day's production output.
- Measure and record the true dimensional repeatability of each weldment by analyzing and documenting each weld joint and the variability in location, gap and configuration.
Weldment Fixtures and Tooling:
Robotic welding systems fail due to poorly designed fixtures. Proper fixtures must:
- Position or deflect weldment components to a repeatable location.
- Hold that location securely throughout the welding cycle.
- Operate without hindering robotic arm or torch movements during the welding sequence.
- Enable the operator to load/unload weldment components safely.
- Allow for simple replacement for critical tooling or wear components.
- Provide for effective fixture removal and replacement in the system.
Prior to the systems integrator designing and building the fixtures, the following should be provided:
- Final weldment drawings
- Critical dimensions
- Completed reference weldments
- Several sets of components for each key weldment to be completed
System Feasibility and Cost Justification:
After the systems integrator analyzes the key weldments, collects actual weld production data, and reviews the true dimensional repeatability information, a welding cycle time study for each of the key weldments should be performed.