Cutting Aluminum

My MPCNC has a cut area of about 9" by 9" by 3.5" and I made it to mill aluminum. I have been running my first tests cuts and I am using a 1/8" flat carbide end mill made for aluminum that I got from Mcmaster. I just tried to run a test cut with .2 mm depth per pass and 3mm/s rate of cut. It went pretty well for about the first 5 mm, but it started to push the aluminum around. The aluminum was well secured it just stopped cutting for some reason. After further inspection, I noticed that aluminum was lodged in between the flutes of the end mill and covering the sharp edges. What can I do to stop this? What depths and speeds have you guys had success with?




Carson Roff

Do a search for posts by Kevin Lopez. He is kinda the resident expert on aluminum milling with MPCNC. He has some videos and he mentions some different settings along the way. Every machine is different so it is tough to just throw out numbers.

Also, google search for Lye and/or Sodium hydroxide for info on how to clean the fused aluminum off your end mill.

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I think you are going to shallow and too slow. Due to the high rpm of the spindle and your slow and shallow feed rate it caused a lot of excess heat. You were basically friction welding the bit to the aluminum. As Mike mentions above check out Kevin’s work. He has it the MPCNC working well with aluminum. You should be able to match his speeds with your small machine since it should be very rigid.

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Agreed, and start with wood, then plastic. The cost of a mistake is much lower in those materials. Once everything is good then step up. I highly suggest not starting in aluminum.