Spindle Speed

​Program a part in CAM and the milling tool is a smooth cylinder cutting through a prismatic part. In reality, it is not a cylinder, it is a bundle of rotating teeth in a flexible toolholder. Every tooth impact causes the tool to deflect and snap back when that tooth exits. The slots measured in figures 2 and 3 were cut with the same endmill in the same toolholder in the same machine cutting at the same depth at the same feed per tooth. The only difference was the spindle speed. In Figure 2, the speed and the tooth impact rate were synchronized. 

Getting the speed right is the single most impactful thing you can do in milling. If you are able to do it on a consistent basis, it will slash setup and cycle times. Perishable cutting tools and spindles will last longer. Your costs will drop. It will make the unprofitable, profitable. You will gain more open time and you will win more work to fill it. It will justify investments in new tooling, software and machine tool technology.