RAPOLAC Rapid Production of Large Aerospace Components
The Shaped Metal Deposition (SMD) process is a novel manufacturing technique developed and patented by Rolls-Royce in order to produce mechanical parts directly from a CAD model. The work developed has been carried out in the frame of the RAPOLAC EC project (www.RAPOLAC.eu), and aims to investigate upon an automatic control system, in order to free the operator from constant monitoring and manually acting on the welding process parameters. The innovative aspect of the SMD process consists of reversing the production philosophy actuated up to now, by the traditional rapid prototyping methods, such as machining. This method is based on the material remove from the work piece, in order to obtain a desired final shape. There are several evident drawbacks in this process, like the large waste of material in scraps and the consequent increase of the costs, depending of the material used. The SMD process reverses this destructive production philosophy and works by adding progressively the material to the final work piece, in order to obtain the desired shaped component. This means that effectively no process scraps are produced minimizing the material used to the strictly amount required by the final work piece shape. Two versions of the SMD plant have been developed. A TIG welding machine working together with a KUKA industrial manipulator has been set up for melting stainess steel (upper figure). Also a three axis CNC machine has been used as a small scale version of the SMD plant for melting tin (lower figure).