The Programming of Router Bits
There are many things to consider before you use router bits, such as the programming of the machine to ensure the right finish on the cut edge of the material. The feeds and speeds are the first thing that you must program into the plastic machining or composite milling machines that you are using. The manufacturer will likely recommend the feeds and speeds, though, and through trial and error you can figure out the most appropriate setting for the materials that you tend to use.
The next step when programming a cutting machine for composite milling or some other specific job is to choose the cutting method. Both conventional and climb cutting have their place depending on the diameter of the bits. Router bits of a larger diameter typically perform better with a conventional cut mode, but router bits with smaller diameters are often dependant on the material and must be tested. If you have found a perfect plastic routing cut mode for a soft plastic, for example, it might be totally inappropriate for composites or hard plastics.
There are other programming considerations to make before you use any type of router bits, such as finish passes and entry points. Router bits with smaller diameters are usually the only tools that require finish passes for the optimal edge finishes. Without at least .015” to .030” of material to remove, most plastic routing bits will actually produce a deteriorated finished edge.
Entry points can also be a troublesome issue during programming for composite milling and plastic routing bits. The most common method is to slow the feed rates down to compensate for chip wrap problems, but a ramped entry can also work just as well. Router bits also don’t have a centering point like drills do. But by entering the cut by plunging into a scrap area and moving to the final cut path in a lateral direction will compensate for this.