Constant Deposition

In this video, Andrew Waite, one of FANUC America’s engineers in the Materials Joining Group, shows in-depth information regarding constant deposition, one of the arc process controls. Constant deposition is the method to match filler wire to robot motion, specifically TCP travel speeds. It works by using a run-in schedule as a lower limit of the welding process. The robot will be able to monitor changes in the travel speeds and adjust wire feed speed and trim accordingly. We use constant deposition so the wire feed speed and travel speed ratio can be maintained or adjusted throughout the progression of the weld. There are limitations in the process to stay aware of. Andrew discusses these limitations which explain where constant deposition is not applicable, not compatible, or non-adjustable. The applications of constant deposition are, weld starts, or directional changes, essentially where a robot goes through an acceleration and deceleration profile. Constant deposition maintains consistent volumetric weld deposition as the robot goes through slight physical limitations. For example, at an arc start the robot is at a stop and goes through an acceleration profile as it gets up to commanded weld speed and without the use of constant deposition the weld profile will have excessive deposit creating what industry has termed “Dog Bone. Constant deposition will dynamically increase the weld deposition rate as the robot accelerates, eliminating the excessive deposit and providing a uniform weld profile. Constant Deposition is a tool to minimize the amount of effort a programmer needs to make to achieve a uniform weld profile as the robot transitions though acceleration and decelerations. Andrew concludes the video with factors to keep in mind when you are considering implementing constant deposition into a welding process.