Deep Pocket In Aluminum

Hi All,

Need some advise on how to Rough out a 3.5" dp. pocket in a 3.5656x 5.375 x 7.125 alum..I want to use an indexable end mill 1.0"dia. @.50doc.,Then use a carbide endmill to finish the walls and floor ,need at least a 32 finish.What I wanted to know is should I plunge rough the pocket out first or just use the indexable to rough.I am using a new Haas VF-3SS Vertical mill with thru spindle coolant and programable coolant and air blast.This is a semi production(ten pcs or less).I am usin three vises,One to do pocketing drilling on first side,Second vise for the bottom side(adjacent),Third vise to do side holes.Any advise would be very helpful and grateful.


John

I would not use the indexable for roughing the deep hole as they generally do not have the best "flutes" for pulling chips out. I would reccomend a high helix (55 - 60 deg) 2 flute endmill. I use CGS 2000 series mills, very aggressive in aluminum and if you buy right from manufacturer not bad price either, They also seem to last forever and give excellent surface finish for finishing passes. The 32 finish should not be a problem with these or other high helix mills. If you got a 1" high helix mill I would take a lot more than .50" doc, I have taken 5/8" doc with 1/2" endmill full stepover before with no chatter problems at all. The best thing adout the high helix mills is that the chips get pulled right out of the pockets in a nice high arc shower.

I would reccomend lots of coolant especially for the finish cut as if any chips get recut you get a kind of wrinkled finish.

just my 2 cents
JP