I need to drill several holes using a 1/16" drill bit at 0.72" deep.
My machine is good at 6000 rpm. I could go 7500 if needed.
I am doing the following:
Pre-drill using a 1/16" carbide bit to 0.03" deep
I then change to a new HSS bit at 6000 rpm and feed of 6 ipm.
Down at 0.06" increments and lifting 0.005" for a chip break.
I do that three times to get to -.18"
I keep the bit at/below 0.18" to avoid chips going into the hole.
I then peck at 0.06" increments and lifting the bit to -.18".
I use only feeds and retract at 88 ipm.
I then lower to .005 of the previous depth at 55 ipm and drill again at 6 ipm
My coolant is 6 jets from around the quill.
After 10 test holes, the bit is trash.
I am drilling at 0.001" per revolution.
What am I doing wrong?
For those interested...
My sub code is the following:
O223
(Chip Breaker
G0 X=VC5 Y0 (VC5 IS IN A TEST LOOP FOR X POSITION)
G0 Z.01
G1 Z0 F6
VC2=0
N200
VC2=VC2+.06
G1Z=-VC2
G1Z=-[VC2-.005]
IF [VC2 LT .18] GOTO N200
(Peck cycle
VC3=.18
N201
VC3=VC3+.06
G1 Z=-VC3 F6
G1 Z=-.18 F88
G1 Z=-[VC3-.005]F55
IF [VC3 LT .72] GOTO N201
G1 Z.1 F88
G0 Z.3
RTS