[KSky]

Every now and then I end up with this rats nest with small drills on my CNC Mill. What am I doing wrong?

This is a #10 drill in mild steel, 1600 RPM, 1.5IPM. Right from GWizard.

[G59]

Straight drilling or a peck cycle? Peck drilling usually breaks the chip in smaller pieces. Never had a problem in mild steel though. Strange.
I usually get the rats nest like that in Aluminum 6061. It has alot to do with the feedrate and possibly insufficient retraction from the hole.

[KSky]

Am using sheetcam, so it has it's own peck cycle. Not using G73. The rats nest just starts and builds and builds.

It drills down .13, then retracts .04

M08 (Flood coolant on)
S1599 M03
X1.4300 Y1.4300
Z0.0200
G01 Z-0.130 F1.25
G00 Z-0.0906
Z-0.1100
G01 Z-0.260
G00 Z-0.2206
Z-0.2400
G01 Z-0.308
G00 Z0.0500

[G59]

Exactly, it doesn't retract far enough for the chips to fly out of the hole and off the drill.

[KSky]

Is there a rule for how much to retract? I don't see suggestions for this in either G-Wizard or Sheetcam.

[G59]

I don't know of a rule. But try increasing the retract point to completely out of the hole.
I used to know this, but I think old age is creeping up.

[AARONT]

Your feed is too low also. Kick up the feed to about 5ipm or .003/rev. I have had good luck dividing the drill diameter by 62 to get my feed.

[Superman]

Every now and then I end up with this rats nest with small drills on my CNC Mill. What am I doing wrong?

This is a #10 drill in mild steel, 1600 RPM, 1.5IPM. Right from GWizard.

#10 = 0.1935" = 4.9mm
1600RPM = 80 SFM = 25 m/min
F1.5@S1600 = 0.00094"/rev = 0.024mm/rev......your program shows F1.25

these numbers are much too slow. You need a thicker/shorter chip chart link

the feedrate is more suited to 1/16" drill
- as you use an increasing drill size, the feedrate is also increased, as the drill is stronger in the "web" thickness
- the chart shows you should be up round the .0040"-0.0060" per rev ( 1/4" is 0.006 )
- cutting speed around 100 SFM (30m/min) = S1974 x 0.0040 = F7.9

pecks around 30-50% of drill diameter. You want the chip to push the previous chip out the hole before it has a chance to wind itself around the tool
- your retracts are OK.....I've used machines that have . 0.020" retract for their G73 canned cycles. I have a larger retract for their G83 cycles