108 Appendix CAD/CAM (ComputerAssisted Design±ComputerAssisted Manufacturing) As stated before, this book is not about the actual technique of designing (delineating) molds, but about the logic and reasons behind a successful mold design and the questions the designer must consider and answer at every step of the design process Computers now play an important part in this process, especially if there are many precedents accessible to the designer to be used for new designs and if there is a large collection of standards that can be accessed from computer memories without the need for tediously drawing and redrawing, from simple parts to complicated subassemblies Also, by using special programs, many calculations can be performed rapidly and accurately, and newly created mold designs can be easily checked for ef®ciency of plastics ¯ow, cooling, strength of materials, cam motions, and so on Because there are so many design programs, the designer usually starts by redrawing the customer's information, which may have been submitted as hard copy (prints) or electronically, but originating from a different system than the one used by the designer Once the to be molded part (the product) is drawn and dimensioned to the designer's shop rules, a program will be used to add the mold shrinkage to established rules A constant factor may be used for the product, or different shrinkages may be applicable, as explained earlier in this book The designer will now go through the motions as explained earlier, either designing ``from scratch,'' or searching the ®les for a suitable precedent If a good precedent is found, it can now be merged with the new product drawing and the mold can be designed Once completed in principle, various programs can be used to check selected areas (plates, cavities, etc.) for physical strength and to check with other programs the expected ef®ciency of ®lling the mold cavities, gate location and sizes, runner sizes, the cooling layout, and so on Note that all results from using these programs depend on the accuracy of the data CAD/CAM (Computer-Assisted Design±Computer-Assisted Manufacturing) 109 provided, such as reasonable assumptions as to temperatures, pressures, times, and so on Once the mold drawings are ®nished, they are transferred to the manufacturing group By using related, compatible CAM programs, which are often developed in-house, and the input of experienced machinist/programmers, the manufacturing group will determine the best tools to use for the selected machine tools and the appropriate tool paths for each mold part for each tool and for each machine tool The following is a list of better known and widely used CAD and CAM programs CAD/CAM Programs Autocad, Autodesk Canada Inc (mostly for PCs) 90 Allstate Parkway, Suite 201, Markham, ON, Canada L3R 6H3 905-946-0928 Unigraphics, Unigraphics Solutions 2550 Matheson Blvd., Mississauga, ON, Canada L4W 4Z1 905-212-4500 Proengineer, Parametric Technologies Co 128 Technology Dr., Waltham, MA 02453, USA 781-398-5000 Fluid Flow Programs CADMOULD, Simcon Inc (mold¯ow, cooling, shrinking and warpage) 10914 N 39th St., Suite B-4, Vancouver, WA 98682 888-754-8628 MOLDFLOW, Mold¯ow Corp (mold ¯ow, cooling) 91 Hartwell Ave., Lexington, MA 02421, USA 781-674-0085 FEMAP Enterprise (¯uid ¯ow, all ¯uids) PO 1172, Exton, PA 19341, USA 610-458-3660 110 CAD/CAM (Computer-Assisted Design±Computer-Assisted Manufacturing) FIDAP, SPRC (¯uid ¯ow) 1155 North Service Rd., Suite 11, Oakville, ON, Canada L6M 3E3 905-465-1733 (partner for Fluid Dynamics International, 708-491-0200) Mechanical Stresses ANSIS Mechanical Dynamics Ltd 400 Carlingview Dr Toronto, ON, Canada M9W 5X9 416-674-2144 AL GOR 150 Beta Dr., Pittsburg, PA 15288, USA 412-967-2700