I like to try to compile recommendations for aluminum settings from different sources. I was watching the sienci video of milling a handle and they are running much faster than recommended surface speeds for roughing with carbide tooling (1981 SFM), Just cruising Amana’s recommended SFM and they list something like 600SFM for roughing.
I’ve read kind of a rule of thumb for carbide aluminum cutting is 600-1200. Are they burning up bits or is there a lot of flexibility here?
Personally I adaptive rough aluminum in the 1200SFM range but 2k seems bonkers. Feedback?
You didn’t say what alloy you’re using. Aluminum can run from very soft to very hard and the correct cutting parameters vary along with it. Softer aluminum tends to gum up the tool and is trickier to dial in. Keeping the tool cool is the key.
6061 mostly. It seems to me that if you maintain healthy chipload so heat is being removed in the chip, then you should be able to push SFM as long as chatter and spindle power aren’t an issue. My worry is that it overheats the tool even if the chip is healthy.
Years ago I did some speed tests for an aircraft component part manufacturer. They sent in a few sheets of 1-⅛” 6061. I was able to cut it with a ⅜” diameter tool at 230 ipm, ¼” per pass. The chips were scalding hot (I still have scars on my arms from them landing on me) but the tool held up fine. The problem was clearing the chips out of the kerf rather than recutting them.
With smaller bits I have had more problem breaking them before I get to a chip load that is typically recommended. For cutting out this, I used a 1.8mm bit only cutting 0.002 depth at only 40 ipm. I probably could have gone a little more aggressive but after breaking two bits I dialed it way back.
It takes some experience to cut AL, which I don’t yet have, but working on it.
