8
End mill snapped at 30% feed, tool path was the real problem
Had a 1/4 inch carbide end mill blow up on a Friday afternoon cutting 6061 aluminum. Thought it was the feed rate since I was only running 30% of recommended, but after digging into the CAM file I saw the stepover was way too aggressive on a 0.02 inch deep pocket. The corners were loading up every pass, so the tool was flexing and eventually just let go at the last radius. I re-cut the part with a trochoidal path at 0.005 stepover, doubled the speed, and it ran smooth as butter. Cost me a $18 tool and 3 hours of rework to learn that checking the tool path is more important than babying the feed. Anyone else had a failure that turned out to be a geometry issue instead of speeds and feeds?
1 comments
Log in to join the discussion
Log In1 Comment
shane_fisher3718d ago
That 18 dollar blowup hits different when you realize the CAM file was the real villain. I used to be the guy who would just dial back the feed to 20% and pray, thought any chatter or breakage was automatically a speed problem. Then I had a 3/8 rougher die on a tool steel block, same deal, checked the path and saw the stepover was nearly half the tool diameter on a tight corner. Swapped to a smaller radial engagement with higher feed and it cut clean, no drama. Now I always run the simulation and watch the tool load in the corners before I ever touch the spindle. Geometry is the silent killer man, speeds and feeds get all the blame.
2