[Vulin]

I somewhat of a new machinist, only been at it for about 3 years. Ive had the chance to machine various materials, etc. My current job at the moment (soon) does not have any CAM, so take that in to account.

Ok, I have machined quite a bit of alum bronze, but not with an end mill this small. It will be 4 flute, and suited for the material. The problem, I have to remove a decent amount of material, going .375 in depth, and it all has to be done with a .062 end mill for space. Just looking for some tips, on depth of cut, and feed? I was thinking something around 7500rpm, 15ipm (.0005 cpt) and about .015 depth. I know a decent chip load is needed for the material, but Im not sure how much the end mill could take. Id also like some info on drilling with the smallest drill being around .031 and the largest being .078 both carbide. Im really used to larger tooling thats not as easily breakable.

[RCaffin]

I have machined quite a bit of alum bronze, but not with an end mill this small. It will be 4 flute, and suited for the material.

A 4-flute is going to load up fairly easily, while a 2-flute is much weaker. Have you considered a 3-flute?

Otherwise, budget for some spares while you learn :-)

Oh yes - spindle runout and shake can be a problem that small.

Cheers

[packrat]

A 4-flute is going to load up fairly easily, while a 2-flute is much weaker. Have you considered a 3-flute?

Otherwise, budget for some spares while you learn :-)

Oh yes - spindle runout and shake can be a problem that small.

Cheers

You have it backward. A two-flute is stronger than a four-flute. If you look at both from the bottom cutting end there is more metal in a two- flute.

[rurilubo...c]

I would disagree, imo 2 flute is weaker, it may have a bigger web, but lacks the rigidity the additional flutes provide. I am a big fan of 3 flutes, especially in small diameters.
I am curious to see how you go .375 deep with an em that small, usually extended length
ems in small diameter are 3 times the dia for loc. 3/16 is extended length for a 1/16 em. You may be able to get something .25 with some searching but 3/8 is going to be a chore. If somehow you find something that long it is gonna be a nightmare to get any kind of finish.