Feeds and speeds are typically the best known variables as far as cutting parameters and they are extremely sensitive to minor variations. Unlike many other commonly routed materials, plastics, and particularly acrylics, have an extremely narrow chip load range that can be used to produce an optimal finish (see Figure 7). Each cutter (based on configuration and diameter) will have a different optimum chip load for each material type. As a rule of thumb, the following feed rates are good starting points if the goal is optimum edge finish. A constant spindle speed of 18,000 rpm and a depth of cut equal to the cutter diameter is assumed.
- 1/8” Diameter Tooling: 75-100 ipm
- 1/4” Diameter Tooling: 100-200 ipm
- 3/8” Diameter Tooling: 125 ipm to 250 ipm
- 1/2” Diameter Tooling: 150 ipm to 300 ipm