Adding a finish to your parts isn’t always vital, but it is certainly one of the more entertaining parts of machining. For those who are looking for a finish that is arguably one of the most classic, engine turning will add a unique sheen to your parts. One of the most recognizable displays of engine turning was seen on Charles Lindbergh’s famous aircraft, the Spirit of St. Louis. Engine turning can be done in a number of ways, but we utilized a Tormach Tension/Compression Tapping Head and some Cratex Rods that we picked up from an industrial supplier. Since the rods are an abrasive material and we did this process in aluminum, we used an extra fine grit – heavier grits would be recommended for harder metals like steel. We wrote a G-code program by hand to create the engine turning pattern on a block of aluminum. This specific G-code program uses subroutines, which some users may not have seen before. For more information on subroutine programming, please see Chapter 7 of the Tormach Operator's Manual or CNC Cookbook’s post on subroutines. *This G-code is for sample purposes only – Tormach Tech Support cannot help you debug code.