CNC Tips and Techniques

CNC Tips

When you need to cut a precise angle on a part, set it up in the machine with a protractor and then write a program to follow the angle with an indicator, this way you can bump the part around while your machine is indicating.	If you still have to manually input you're programs at the machine control, you can save yourself considerable time and keystokes if you write small sub-programs (or templates) for code that repeats over and over.
Progressive fixturing? Figure out how to fixture or hold down parts in sequnce so that a finished part is produced at the end of a cycle, not only does this save handling time, it also allows you to detect machining problems before they become a major headache, it takes a lot of extra figuring but pays off in the long run in a big way!	If you need to machine both ends of a part while you're holding it in a vise, and you also need a stop try using one of tools for the stop, just take 1/2 the dia. of the tool +1/16 and add this to your program. This way you can bump the part against the tool, press cycle start and the tool/stop moves out of the way! I usually use the center drill for this.
Did you know that you can use negetive offsets on machining centers to make an inside and outside part using the same program, you can just make sure you have enough room to move into cutter comp.	Thread milling? no problem, just remember to use the shortest possible solid holder you can find, I've tried using collets and they seem to allow the tool to chatter to much for my liking.
Mirror image works great for producing right and left hand parts, but watch out when machining the mirrored part, if you've programmed the first part using G41 and climb milling, make sure you add at least an extra .01 to the rough cutter, because on the mirrored part you'll be conventional milling where the cutter tends to dig into the finished surface.	The following Tips were used by permission from John Tomasura of: Stellar Programming & Machining