May 2025 Volume 7

AUTOMATION

Gouged Model ready for alignment with machined model for programming of weld paths

scanning is needed, it is cleaner and 100% repeatable. With robotic welding, a 3D laser scanner is a valuable tool to have in your toolbox. Along with using it to obtain the geometry of the gouged die or component it can also be used to check if enough material was removed. The gouged model can be overlaid with the finished machine model and then sections can be sliced. The programmer can then check the difference between the two models and see how much stock material was removed. The amount of stock material removed is important. If too little is removed, it will result in not enough weld material to be applied, and the machined surface of the die or component will not be pure weld metal but an admix of parent metal and weld metal. With the robotic system we are looking for roughly 10 – 12 mm of material to be removed to achieve pure weld metal at the working surface for best results in service. If too much stock material is removed, it will result in using more weld alloy than expected. The laser scanner can again be used after the welding job is done to accurately check the final welding deposit thickness. This is done by using the color mapping portion of the scanning software. It will show the low and high spots on the welded die or component in a range of different colors. This information can be used to optimize future welding jobs of the same die or component. If the die or component is having too little or too much weld being applied consistently, the welding programs can be modified to address this issue. Once the work piece is prepared for welding, by either gouging or machining, and the geometry has been obtained, the programming can begin. The programmer will need to import and align the models and input a series of parameters that the software needs to generate the target mesh or welded geometry and compute the weld path calculations. Now that the weld path calculations have been generated, they need to be translated into robot movements. The software is equipped with a virtual cell where the geometry of the robot with Post-processing. Converting weld path calculations and target mesh into robot movements in virtual cell

Weld path calculations finished

Target mesh calculated

with safety enclosures and safety systems that include door sensors, emergency stop buttons and a control panel. Optional items that can be equipped are self-cleaning torch stations, electrically heated welding tables and servo track systems for larger systems. There are two conventional methods used for preparing a die or component for welding, carbon arc gouging and machining. Carbon arc gouging is the quicker and more economical method but due to its nature it does not produce the same prepared geometry every time like machining does. The quality of the gouge is largely dependent on the skill of the operator and the result will vary in quality between operators. Because of this, a laser scanning arm of some type is needed to obtain that gouged geometry of the die or component for programming the welding job. If the die or component is prepared for welding by machining the geometry of that machined prepared die or component will have a CAD file that can be utilized for programming. Another added benefit of a pre-machined impression is that no laser

FIA MAGAZINE | MAY 2025 24