Observations on Routing Aluminum | |
I recently finished a 3 axis gantry router for work that is designed to cut complex notches in aluminum curtainwall (window) extrusions. While programming the machine I had trouble getting things to work correctly and I couldn't understand why. I was using info I found on this site, as well as in the Machinery's Handbook to set my feed and speed and still the machine just was not working as intended.
Finally it dawned on me one day that I was not "Milling" aluminum, I was "Routing" aluminum. I took everything I had been told about milling and threw it out the window. With a stopwatch in hand I headed down to the shop and grabbed a porter cable router (just like the one on the gantry) and found a piece of scrap to experiment on.
What I found is that the Router has a "natural" feed rate at which it will cut through aluminum, and that natural feed rate is much slower than "the book" says.
Based on my own testing here is the data that I've been using to set my speed and feed rates.
Tool: 3/8" 2 Flute End Mill
Speed: 21,000 RPM (Max)
Coolant: KoolMist (Pressurized Air & Mist Coolant)
Material: 6063-T5 Aluminum Extrusion 1/8" Wall Thickness
Depth of Cut: .125" (Full)
Width of Cut: .375" (Full)
Feed Rate: 5 - 10 in/min (Depends on Machine Rigidity)
Depth of Cut: .050"
Width of Cut: .375" (Full)
Feed Rate: 15 - 18 in/min
Depth of Cut: .125 (Full)
Width of Cut: .1875 (Half)
Feed Rate: 22 - 25 in/min
Depth of Cut: 1.0" (Face Finishing Pass)
Width of Cut: 0.02"
Feed Rate: 25 - 30 in/min
Keep in mind that these feed rates will shorten tool life if you're using a regular HSS end mill. However that has to be balanced against the cost of replacing the router due to overloading it. Even with a "shorter" tool life I've still been getting well over 40 hours of cutting time out of each end mill.
I would also like to note that I have been having better luck keeping tolerances by programming the router to cut in a "Climb Cutting" configuration instead of "Up Cutting".
These are just my observations, but I figured someone else might find them useful.  |