HELP! Problem drilling 2.39 dia hole in Ali casting

Hi,

I am trying to drill 500 off 2.395mm dia holes in an ali casting but the drill I am using keeps building up with swarf on the drill flutes after just one hole has been drilled.

I am using a special sphinx drill for this job but would like some help with why the drill is building up with swarf.

I am using a horizontal milling machine to do this job and I have tried the following speeds and feeds

S10000 F600
S10000 F400
S6000 F300

I am using G83 peck cycle with pecks on 3.5mm and the hole is 10mm thru.

I have also tried using thru spindle coolant and still no luck.

Any help would be appreciated.

Have you tried blowing air at it with a decent pressure while drilling ?

Have you tried wd40? Apparently it's the bees knees for cutting aluminum.

Is the feedrate within spec for the particular drill you're using?

So far you've tried-
0.06mm/rev
0.04mm/rev
0.05mm/rev

Looking at a basic polished cobalt drill (you are using polished drills?), the recommended feedrate should be about 0.1mm/rev, while a solid carbide is slightly higher depending on the alloy, and high-helix drills being higher yet at around 0.15mm/rev.

Hi Woolley
You really need a suitable coolant,and that would be parrafin.