Old World
The patternmaking process traditionally begins with one of our craftsmen fully assessing a conceptual drawing or original casting provided for the purpose. A full size hand drawn layout of the piece is produced adjusted dimensionally for any shrinkage that will occur as the cast metal cools in the mold. He will use this layout as a reference for creating the profiles and dimensions needed to build the pattern. The type of pattern needed by the foundry depends upon the number of molding cycles or pattern durability required. This determines what materials he will use in creating the pattern. Pattern building materials can include wood, metal, plastic or composite materials in a combination of turned, sculpted and fabricated components all assembled to make one finished pattern. Often high volume patterns are cast as a monolithic aluminum match plate before production. All this is by necessity a lengthy and somewhat time consuming series of events.

New Tech
Now we have the option of using the CNC router to simplify the process. The router can make intricate cuts on multiple levels in rapid time with extreme precision. With the ability to drill, mill or cut, the possibilities are almost endless. Using the customary drawing or sample as a reference the router operator renders (draws) the project in Mastercam in either 3-D or as a line drawing depending on the complexity of the part. Before sending the program to the router it can be put through a trial tool run to see if the tool path is correct. Essentially you see the part being cut in 3-D on screen before the router physically cuts it from stock material. The ability to "build" the part in 3-D and view the piece in multiple colors for enhanced visibility, gives the operator lots of flexibility. Once all the details are complete the program is sent to the router control center to begin the cutting operation. The router can use as many as ten different tools to form the specific contours of the part. It will automatically pull up to the tool carousel, pick out the next tool it needs and move back to the part to resume operations. As all of these operations can be performed upon one single monolithic material the necessity of converting a composite pattern is eliminated. A 122" x 59" cutting surface allows plenty of room for large projects down to the smallest and most finely detailed pieces.

Projects
Some of our latest projects to be accomplished in this manner include:

• A lamp post pattern for Serenbe, Palmetto, Georgia consisting of undulating curves decreasing in diameter from base to tip.
• A diamond tread and riser pattern for the entrance stairs to Lincoln Cottage, Washington, DC.
• An intricate star shape for a grill pattern for the U.S. Supreme Court, Washington, D.C.

With this new technology Robinson Iron looks to the future with 20/20 vision while giving life to past and present ideas.