Wire and Arc Additive Manufacturing is a manufacturing process where welding torch is used together with a robot arm or other CNC manipulator to produce parts. During weld cladding, the torch is moved in 3D space according to the CNC program. To achieve a desired geometry of the weld bead when making small size parts, previously deposited weld has to be cooled down beneath a certain temperature. For that reason, temperature controller based on an IR thermometer was developed. Temperature controller and welding source communicate with the CNC controller, which is responsible for coordinated operation of the system. Custom control programs had to be developed. To remove excess heat from the welded part faster, automated cooling with compressed air was added to the system. Cooling effectiveness was evaluated by manufacturing multiple vertical walls. The results show that such cooling is especially effective when welding high parts with short welding trajectories. Welding system was also tested by welding different shell objects. It turns out that inconsistent ignitions of the welding arc can drastically effect the quality of the welded part. They are one of the main reasons for surface defects that also lead to deviations in the welded part geometry from the programmed geometry.
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