Feed and DOC advice 1/16 BN EM

[mm37]

Looking for some advice on a realistic feed, D.O.C. and stepover for a 1/16 BN EM. The tool is carbide and I have to 3D some 0.030" radius in the bottom and corners of a pocket that is 1.280" deep in 6061 alum. The tool only has 1.0" DOC, so had to grind the shank back about 0.300" for clearance. I figure that i'm going to snap the EM's but i need some suggestions on some feeds, D.O.C and stepover amounts. I've never had to cut with this small of and EM sticking out this far (21 to 1 LD ratio). Is this achievable? Any input or advice would be greatly appreciated. By the way I have a 10,000 rpm spindle and I've roughed the pocket with a 1/8" BN EM.

 

Thanks

[MotorCityMinion]

Off the top of my head I'd say Max RPM is fine. Make sure the tool is running true. Baby the corners first at at say 5k and 40 ipm and if you have the tolerance, offset the corners deeper than the rest of the surfaces. Go back and hit all of the surfaces the at around 10k and 60 ipm. I would finish that with 2 tools though. 1/8 bne for the walls and floors, Starting with a .32 doc on the walls. 1/16 bne to pick the corner rads using a drill cycle to chop/rgh out the verticals. Sounds like a good candidate for finish blend.

[mm37]

Thanks for the input, but I don't think the 1/16" BN EM will ever handle that kind of feed at the LD ratio that I'm having to run. I'm having to run the 1/8" BN EM @ 10K & 10 IPM because of the chatter.

[iowajim62]

Finish the walls down to the top of the 3D surfaces with a 1/8 EM that has a .010-.015 R(bullnose) then use a 3/32 extended BEM grind the flutes off so you only have .100-.125 flute length and semi-finish the 3D surfaces leaving .007-.008 stock. Use max rpm 10 IPM and step over .02 and and step down .010, finally your 1/16 BEM will need like .010 step down and .003 step over at max rpm 3-4 IPM. Use one semi-finish op to finish down on the side surfaces and a 2nd semi-finish op to work the bottom or floor surfaces with the 3/32 semi-finisher. Now copy the semi-finsh ops and change the stock to 0 from .-007-.008 and pick the 1/16 BEM. should work OK, won't be fast. You can adjust stock to leave to get a cleanup from the ugly roughing chatter. You can cheat the Tool Length Offset in the machine to leave material for the finish ops. In other words run the semi-finish op to finish the sides/walls with the tool not touching the bottom of the part. Use an M0 between the wall and floor semi-finish ops to change the tool length offset back to the correct length. Long program that's for sure. Good Luck

[35K chipper]

look at www.harveytool.com they have all the tools

jimmy talked about.

 

35k