Upcut tools are not commonly used when cutting wood or particleboard, for example, since they pull wood chips out of the material and cause unwanted fraying. That said, if the cut edge is not going to be visible in the final application, then upcut tools are a viable option for these materials. They allow a faster spindle speed to be used, thus completing the job in a timely manner.
If the top edge of the work is going to be visible, on the other hand, then a downcut tool is recommended, as it will push the chips away from the surface. The main disadvantage of this scenario is the downcut tool will require a much slower spindle speed, thus reducing the efficiency of the finishing workflow. This slower speed is necessary because it takes much longer to get the chips out of the material as the tool is plunged into the surface. Downcutting at a high rate of speed would create immense heat and could damage the tool.
When a smooth edge is required on both sides of the material, a compression bit can be very useful. The top end of this tool provides a downcut, while the bottom end provides an upcut, creating compression as both flutes meet. In essence, the tool combines the advantages of upcutting—i.e. pulling chips out—and downcutting—i.e. smoothing off both edges. It is important to remember, though, when using a compression tool, the material thickness must be greater than the upcut length, to ensure the smooth finish on both edges.
Such examples show how important it is to find the right tool to cut a given material, optimize the performance of the CNC router and obtain the desired finish. Calculating the correct feed rate will help boost performance while reducing material costs.
Finally, one of the best ways to optimize the performance of a router is thorough, customized training of the sign shop’s workforce. Many issues can be alleviated through the specifically tailored training of employees by dedicated engineers who test tooling, materials and software on a regular basis.