Problem- 6262 Aluminum

[lukehonor]

Hello All...

I'm drilling two .070" holes in 6262 aluminum and I'm having some problems. The holes in questions are .070" DIA and 12 X deep. They are off center and on the face of the part.

I'm running this job on a Tsugami SS32. I'm drilling from the sub-spindle, using a live tooling position. I'm using a solid carbide OSG drill with no spot. My drill is in an ER collet. I drill with a stubby pilot drill first so i have a good start for my .070" to follow. I broke three drills and i'm not more than 200 pieces into the run.

Any suggestions on how I should run my .070" drill after the pilot drill? One pass...? Should i peck...?

Thanks!

[Geof]

Have you dealt with 6262 before? It is a free-turning alloy and in my experience with turning and milling the chips come of in nice small flakes. But what I have found with drilling is that these small flakes jam up in the flutes of the drill and don't clear away. I haven't drilled that diameter that deep, smallest I did was 1/8", but if you haven't already tried it I suggest short pecks (1/2D?) and plenty of coolant.

[lukehonor]

Geof,

Thanks for your input. I just programmed some pecks in there and I'm trying it now. It ran a few and didn't break. I hope it works.

Precision CNC Machining - Progressive Turnings -