DOES THE IDEA OF A PROJECT RESULT FROM A CRITICAL ANALYSIS OF THE APPLICATION OF THE APPLICATION? OF 3D MAKING TECHNOLOGIES? DO THE LIMITS LIE MAINLY IN THE LOW SPEED? IMPLEMENTING, LIMITING PRINTABLE MATERIALS IN DIMENSIONAL TOLERANCES AND IN QUALIT? FINISH PRODUCTS. IN ADDITION TO THESE GENERAL PROBLEMS, SECTOR SPECIFIC PROBLEMS INCLUDE: USE OF PRECIOUS METALS, EXTREME VARIABILIT? OUTPUT IN TERMS OF SHAPE, SIZE AND NUMBER OF SIT? ARE THE LOTS, HIGH LEVELS OF QUALIFICATION FOR THE INTEGRATED AND EFFECTIVE USE OF THIS TECHNOLOGY, WITH THE NEED? TO MAINTAIN PARALLEL PRODUCTION CHAINS WITH CONSEQUENT PERSONNEL AND INVESTMENT COSTS. IN ORDER TO ALLOW 3D (T3D) TECHNIQUES TO ENTER THIS SECTOR AND REACH A LEVEL OF SUSTAINBIEN? ECONOMY? IS IT NECESSARY TO OVERCOME THE DIFFICULTIES ENCOUNTERED? WHAT IS THE FIRST SUMMARY OF THE FACTS IS THAT THE MISTRUST OF THE OPERATORS THAT HAVE REMAINED IN THE PAST HAS BEEN OVERCOME? THE TIME FRAME IS, OR