Warning: I saw a crash at the 2022 IMTS show that made me rethink coolant use

I was watching a demo on a new 5-axis machine in Chicago, and the operator was running it dry to show off the finish. The part was aluminum, and after about fifteen minutes, we all heard that awful sound of a tool snapping and the part shifting. The rep tried to play it off, but seeing a $400 tool and a ruined block of 6061 changed my mind. Now I always use flood coolant for aluminum, even on short runs. Anyone else stick with flood after seeing a dry cut go wrong?

3 comments

3 Comments

casey8432mo ago

Read a study that backs up what @harperschmidt said, showing heat causes most aluminum welding issues. Flood coolant just makes sense after that.

samthompson8d ago

Have you ever run aluminum dry with the right chip load and a good chip groove? I've been machining for about 15 years now and I find a sharp end mill with a proper coating and high pressure air can do just as well as flood coolant on aluminum, without the mess and coolant smell. The key is keeping that chip moving out of the cut, not just cooling the part. Blue chips on aluminum mean you're already in trouble with built-up edge, so I aim for straw colored chips instead.

harperschmidt2mo ago

That demo crash sounds brutal. A machinist I follow online always talks about heat being the real problem with aluminum. The chips can weld themselves back to the tool if they get too hot, even on a short cycle. His rule is that if the chips aren't blue, you're probably okay, but flood coolant is the surest way to keep everything in the safe zone. Seeing a tool fail like that would make anyone a believer in using the coolant pump.