Set up
If a setup piece is available, use the same one throughout all operation setups. For one or two-piece jobs without a set up piece, be extra careful. Stop and check and measure twice. Or find a piece of scrap material that could be used as a set up piece. And run through the graphics page in the machine’s control to verify prior to running.
Check for inferior castings. Castings with excessive runout are not worth using because often some of their surfaces won’t clean up. These castings can also cause machine crashes or the machine to throw the part.
It is better to be safe than sorry. If there is a concern about a setup’s stability or its ability to safely hold a part, ask another machinist for an opinion. There might be a better way.
Machining
When turning or boring and a good finish is not required, but you want an edge break, program a radius of 0.01 at a feed of 0.005. Turn back the tool’s nose radius, plus radius your cutting and feed at a much higher rate to reduce cycle time.
Before throwing away an insert, use a magnifying glass to look at the edges of inserts to verify that all corners have been thoroughly used. A corner may look used to the naked eye, but under closer inspection, you may find that it has more life to it.
Any time you change number(s) in a program or offset, make sure you know what the machine is going to do by turning down the rapids and watching it carefully.
To cut a keyway in a shaft, ramp down the length, then come back and clean it out. Take several passes to accomplish this to help extend tool life. In addition, there’s no need to drill a hole or plunge down.
For face grooving, initially feed in only 0.020 in., take a measurement, make adjustments and face off.
Practical ideas from M.R.S. Machining (www.mrsmachining.net), an American Machinist 2007 10 Best Shop
