3/4 endmill, 4" necked back

[rbest27]

It's a carbide endmill, destiny viper to be exact. I'm going to be doing a pocket about 3.5 inches deep. I'm looking for depth of cut and speeds and feeds. Material is 6061.

[Geof]

First comment; thanks for the name Destiny Viper...I found their website and am going to look into getting relieved neck mills for deepish hole interpolating that we do.

Regarding your question; is it a circular pocket, recangular, or an irregular shape, are you just going straight in with the mill, no pilot hole, if it is circular what is your size? These can influence how aggressive I would be.

As a reference for a circular pocket without any pilot hole my initial conditions would be:

8000 rpm, Z advance per circle 0.2", tool engagement up to 80% of its diameter, feed 80 to 100 ipm provided I didn't run the spindle load too high.

For a rectangular pocket the conditions would be similar and I would ramp down in some place where the horizontal travel was about 5 times the Z movement.

[rbest27]

Only have a 7500 rpm spindle, but it is a rectangular pocket. I was planning on drilling a nice big hole for it to start in....reduce that ramping in time. Destiny makes them in 2 flute and Hanita's make them in 2 and 3 flutes. Sounds like i'm just going to have to see how much I can make the machine shake.