Old timer told me my tool comp was off and it changed everything

Been running this same CNC mill for like 3 years, getting by with finish passes that looked okay. A retired machinist stopped by the shop last week to pick up some parts and watched me set up a job. He just said 'your comp is eating into your part about 2 thou on the X' and pointed at my tool offset screen. I went back and measured my test part with a micrometer and sure enough I was off by 0.002 inches. Fixed it and now my parts come out right the first time. Has anyone else had some random guy show up and spot something you've been missing for years?

2 comments

2 Comments

jake9861mo ago

Check the tool tip radius compensation too? Sometimes that's what's really throwing off the numbers even when the main offset looks good.

the_christopher1mo ago

Isn't it funny how the smallest details end up causing the biggest headaches, like that one loose screw that makes a whole piece of furniture wobble? You can check the main measurements all day long, but if that tiny radius is off, the whole cut gets thrown out of whack. Just goes to show sometimes the real problem is hiding in plain sight, not in the big obvious numbers.