Cutter radius compensation can be one of the more difficult programming features to fully master. There are many rules, and when something goes wrong, it can be difficult to diagnose and correct the problem.
Cutter radius compensation can be one of the more difficult programming features to fully master. There are many rules, and when something goes wrong, it can be difficult to diagnose and correct the problem. Just about the time you think you have it all figured out, some new situation arises that you haven’t dealt with before. This can be quite frustrating, especially when a program that has worked in the past is now failing due to some cutter radius compensation alarm. Here we offer five of the most common problems and give some advice for avoiding them.
Insufficient clearance at approach. Almost all versions of cutter radius compensation require that you make a prior position movement in X and Y to get the tool to a position from which tool length compensation can be instated. With most controls, this prior position must be at least the cutter’s radius away from the first surface to mill. If using a 1-inch diameter cutter, for example, the tool must be at least 0.5 inch away from the first surface to mill. Note that with most controls, this prior position also determines the maximum cutter size that can be used. If the positioning movement stays 0.5 inch away from the surface, the largest cutter that will work is 1 inch in diameter. By the way, this is one situation when a program that has successfully run before is now generating an alarm. The last time this program was run, the setup person used an appropriate cutter size, but today the cutter is larger. To avoid this problem, be sure to specify the maximum cutter size on the setup.
The milling cutter doesn’t fit into a recess. Once cutter radius compensation is instated, the control will simply keep the cutter on the right side or left side of all surfaces it sees coming up in the program. All current controls have a look-ahead feature that allows the control to scan at least a few commands into the program. As the cutter is moving along one surface, the control is looking ahead to see what is coming up in the program so it can end the current motion in the appropriate manner. With this look-ahead capability the control can also determine if the tool cannot completely machine one surface without violating another. If a surface is about to be violated, most controls will generate an over-cutting alarm. Finding this kind of problem can be difficult, especially if the drawing isn’t made to scale. I recommend plotting the coordinates from your program on a piece of graph paper. Using a circle the same size as your cutter, try moving the circle around the plotted path to see if the circle can move around all surfaces.
Again, cutter radius compensation can be difficult to fully master. And I know of programmers that have completely given up on cutter radius compensation because they don’t understand it. Given the benefits of cutter radius compensation, be sure to stick with it until you fully understand it.blog comments powered by Disqus