Feeds And Speeds - Aluminum Facing With Carbide On Taig Cnc Mill

[Mike28303]

Hello Machinists,

I just purchased a Taig about five months ago, and am entirely self taught (using what I could find on the internet). I am cutting small molds out of 6061 aluminum.

What is the optimum RPM, IPM, and DOC for a optimum surface finish using a carbide facemill?

I understand that a Fly Cutter with HSS would be ideal, but Carbide is more convenient as my learning curve is already vertical. Of course, if this is the only way to achieve excellent results, I will do it.

My current settings were found with trial and error. One hint to my settings being incorrect is that I must do about two passes in one direction and another two 90 degrees of that in order to be rid of the .001-.002" tall gummy ridges on the sides of each cut.

Current setup:

3/4" Diameter Facemill with two carbide inserts
Climb Milling
Material: Aluminum
RPM: 10,600
IPM: 26
DOC: .005 to get it flat, .002" for the finish.

Here are the Mill specs so you can understand the limitations:

Taig Mill w/Ballscrews
RPM: 1050 to 10,600 (There are five grooves on the spindle, so I can do the following: 1050, 1650. 2600, 4200, 6700, or 10,600)
IPM up to 100
1/4 HP Spindle Motor

I'm using flood coolant as well.

Any advice is appreciated!

 

[GLCarlson]

you're in the ballpark. GWiz says about 60 ipm at 10K for a slot at 0.005, 30 ipm for a best finish cut.

Just be sure you're not taking off too little DOC (and rubbing rather than cutting, thus quickly destroying your tooling).

 

[Mike28303]

you're in the ballpark. GWiz says about 60 ipm at 10K for a slot at 0.005, 30 ipm for a best finish cut.

Just be sure you're not taking off too little DOC (and rubbing rather than cutting, thus quickly destroying your tooling).

Thank you for the advice! I'm wondering if my .002" finish pass DOC is too shallow when using carbide.

Do you think going with a faster IPM would help solve the dilemma with the ridges at the sides of each pass? I've read that aluminum can be pretty gummy - maybe I'm going too slow?