Application of rapid tooling for sheet metal forming: flexible drawing die with punches built by SLS technique and by copying process

The Rapid Prototyping (RP) process is evolving beyond just making three dimensional models and it is beginning to have an impact on tool construction. The sheet metal forming industries are reluctant to implement the Rapid Tooling (RT) process until the costs and time effectiveness have been proved: resulting cost cuts over conventional methods can be significant but justifying the necessary equipment can be difficult. One reason is that benefits of RP are not always easy to quantify; another is that the financial staff may not understand the need for a new technology that can radically change the way a company produces prototypes. A AISI 304 benchmark was selected. Usually it is produced in three steps: drawing; trimming and bending. The combination of prototype drawing dies and laser cutting instead of trimming can answer many questions regarding the development of metal sheet components. This paper regards the evaluation of the possibility to turn out a small batch or sampling production of sheet metal formed by means of flexible drawing die whit punch built using Selective Laser Sintering (SLS) and with one built by copying process applied to a original part produced by Stereolitography (SLA). The results show that both these solutions may be successfully used even if the punch built by SLS technique guaranties higher volume production e parts quality.