CNCMill

Links

• Radial and Axial Depth of Cut
  • Cut Depth and Stepover
  • https://www.harveyperformance.com/in-the-loupe/depth-of-cut/
    • Perimeter Milling
      • RDOC
        • Finishing: 3% - 5% of tool diameter
        • Roughing: 10% to 50% of tool diameter
      • ADOC
        • Shallower for roughing, deeper for finishing.
    • Slotting
      • ADOC
        • Roughing: 10% to 50% of tool diameter
        • Finishing (bottom): 3% - 5% of tool diameter

G-Code

This may be specific to Acorn CNC at HSL.

Comments

Comments are in parentheses.

G0X0Y0 (rapid traverse to origin - the traverse will be executed, but this parenthetical comment is ignored)

Active Units

G20 (set active units to inches)
G21 (set active units to millimeters)

Absolute v. Incremental

G90 (absolute measurements, relative to machine zero)
G91 (incremental measurements, relative to previous ending position)

Feeds

F sets the feed rate in the active units.

G20 (inches)
F15 (15 inches per minute)
G1 X0 Y0 (traverse to origin at 15 IPM) (spaces are optional)
G21 (millimeters)
F375 (375 mm per minute)
G1X0Y0 (traverse to origin at 375mmPM)

Straight Line Traversal

G0 is fast traversal. Careful not to run the tool into the part. Each axis is run at full speed until reaching its destination (ie: the tool follows multiple line segments, not an interpolated straight line).

G21 (set millimeters)
G90 (set absolute coordinates)
G0X3 (fast traverse the X axis to origin + 3 millimeters)
G0X1Y-2.6Z3 (fast traverse to { 1, -2.6, 3 } millimeters)
G0X0Y0Z0 (fast traverse to origin)
G0 X1 Y-2.6 Z3 (fast traverse to { 1, -2.6, 3} mm with spaces for readability)

Straight Line Cuts

G1 is an interpolated straight line from current position to the new position, moving at feed rate.

G21 (set millimeters)
G90 (set absolute coordinates)
F350 (set feed speed to 350mm per minute)
G0X0Y0Z0 (move to origin)
G1X10Y20Z-5 (move in a straight line from {0,0,0} to {10,20,-5} at 350mm per minute)

Plane Selection

G17, G18, G19 select XY, ZX, or YZ as the active plane.

Arc Cuts

G2 is a clockwise cut from the current position { X1, Y1, Z1 } to the destination at { X2, Y2, Z2 } about the center { X1 + I, Y1 + J, Z1 + K }.

G3 is counterclockwise.

If the active plane is XY, all three Z's must be the same and do not need to be specified. The same applies for ZX and Y, and for YZ and X.

Note: I, J, and K are always incremental measurements from X1, Y1, Z1

G17 (set plane to XY)
G90 (set absolute coordinates)
G1 X-1 Y0 Z0 (cut line to {-1, 0, 0 } at feed rate)
G2 X1 Y0 I1 J0 (cut arc to { 1, 0, 0 } about center at { -1 + 1, 0 + 0, 0 } )

Drill Array Pecking

TBD

Bearing Cup

BearingCupVersionOne

Drill Center

;; ------------------------------------
;; Drill Center, Starter Bit (002)
;; ------------------------------------
;; Insert 5/16" or 8mm drill bit
;; Zero Z to shoulder of drill bit

G21 (set units to millimeters)
G90 (set measurements to absolute, relative to machine zero)
F60 (set feed rate to 60mm per minute, 0.025 mm per tooth)
T128 (tool with zero height and diameter)
G43 H128 (height offset zero)

G0 Z20 (traverse to 20mm above part)

G0 X0 Y0 (traverse to screw hole center XY)
G0 Z5 (traverse to 5mm above)
G1 Z-5 (peck to 5mm deep)
G0 Z6 (retract to 6mm above)
G0 Z0 (traverse to 0mm above)
G1 Z-10 (peck to 10mm deep - top has not been faced yet)

G0 Z20 (traverse to 20mm above)

M30 (end of program)

;; ------------------------------------
;; Drill Center, Final Bit (003)
;; ------------------------------------
;; Insert 1/2" or 13mm drill bit
;; Zero Z to shoulder of drill bit

G21 (set units to millimeters)
G90 (set measurements to absolute, relative to machine zero)
F60 (set feed rate to 60mm per minute, 0.025 mm per tooth)
T128 (tool with zero height and diameter)
G43 H128 (height offset zero)

G0 Z20 (traverse to 20mm above part)

G0 X0 Y0 (traverse to screw hole center XY)
G0 Z5 (traverse to 5mm above)
G1 Z-5 (peck to 5mm deep)
G0 Z6 (retract to 6mm above)
G0 Z0 (traverse to 0mm above)
G1 Z-10 (peck to 10mm deep - top has not been faced yet)

G0 Z20 (traverse to 20mm above)

M30 (end of program)

Face Part

;; ----------------------------------------
;; Face Part (004)
;; ----------------------------------------
;; Insert 6mm carbide square end mill
;; Set RPM to 5,000, 300 SFM
;; Zero Z to a grazing cut.

G21 (set units to millimeters)
G90 (set measurements to absolute, relative to machine zero)
F500 (set feed speed to 500mm per minute, 0.025 mm per tooth)
T128 (tool with zero height and diameter)
G43 H128 (height offset zero)

G0 Z20 (traverse to 20mm above part)

G17 (set XY coordinate system for arc cuts)

G0 X20 Y0.56 (traverse to outside part)
G0 Z5 (traverse to 5mm above part)
G1 Z0 (feed to grazing cut)
G1 X6.34 Y9.59 (feed to start of upper right ear)
G2 X6.34 Y9.59 I1.66 J2.5 (CW arc cut to same position about upper right ear)
G3 X-6.34 Y-9.59 I-6.34 J-9.59 (CCW arc cut to lower left ear about origin)
G2 X-6.34 Y-9.59 I-1.66 J-2.5 (CW arc cut to same position about lower left ear)
G3 X6.34 Y9.59 I6.34 J9.59 (CCW arc cut back to where we stared about origin)

G0 Z20 (traverse to 20mm above)
M30 (end of program)

Round Pocket in Center

;; --------------------------------------
;; Round Pocket in Center (005)
;; --------------------------------------
G21 (set units to millimeters)
G90 (set measurements to absolute, relative to machine zero)
F500 (set feed speed to 500mm per minute, 0.025 mm per tooth)
T128 (tool with zero height and diameter)
G43 H128 (height offset zero)

G0 Z20 (traverse to 20mm above)

G0 X0 Y0 (traverse to starting point)

;; Rough Cut for Retainer
G0 Z5 (traverse to 5mm above part)
G1 Z-2 (2mm below surface)
G1 X5.75 Y0 (8.75mm R / 17.5 mm D)
G3 X5.75 Y0 I-5.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-4 (4mm below surface)
G1 X5.75 Y0 (8.75mm R / 17.5 mm D)
G3 X5.75 Y0 I-5.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-6 (6mm below surface)
G1 X5.75 Y0 (8.75mm R / 17.5 mm D)
G3 X5.75 Y0 I-5.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-8 (8mm below surface)
G1 X5.75 Y0 (8.75mm R / 17.5 mm D)
G3 X5.75 Y0 I-5.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-9 (9mm below surface)
G1 X5.75 Y0 (8.75mm R / 17.5 mm D)
G3 X5.75 Y0 I-5.75 J0 (circle about center)
G0 X0 Y0

;; Rough Cut for Bearing Cup
G0 Z5 (traverse to 5mm above part)
G1 Z-2 (2mm below surface)
G1 X7.75 Y0 (10.75mm R / 21.5 mm D)
G3 X7.75 Y0 I-7.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-4 (4mm below surface)
G1 X7.75 Y0 (10.75mm R / 21.5 mm D)
G3 X7.75 Y0 I-7.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-6 (6mm below surface)
G1 X7.75 Y0 (10.75mm R / 21.5 mm D)
G3 X7.75 Y0 I-7.75 J0 (circle about origin)
G0 X0 Y0
G1 Z-6.85 (6.85mm below surface)
G1 X7.80 Y0 (10.80mm R / 21.6 mm D)
G3 X7.80 Y0 I-7.80 J0 (circle about origin)
G0 X0 Y0

;; Finish Cut for Retainer
G0 X0 Y0 (traverse to origin XY)
F200 (set feed speed to 200mm per minute, 0.010 mm per tooth)
G1 Z-9 (feed to 9mm below part)
G1 X6 Y0 (9mm R / 18mm D)
G3 X6 Y0 I-6 J0 (circle about origin)
G0 X0 Y0

;; Finish Cut for Bearing Cup
G0 X0 Y0 (traverse to origin XY)
F200 (set feed speed to 200mm per minute, 0.010 mm per tooth)
G1 Z-7.1 (feed to 7.1mm below surface)
G1 X8.05 Y0 (11.05mm R / 22.1mm D)
G3 X8.05 Y0 I-8.05 J0 (circle about origin)
G0 X0 Y0

G0 Z20 (traverse to 20mm above)
M30 (end of program)

Perimeter Cut

;; --------------------------------------
;; Perimeter Cut (006)
;; --------------------------------------
G21 (set units to millimeters)
G90 (set measurements to absolute, relative to machine zero)
F500 (set feed speed to 500mm per minute, 0.025 mm per tooth)
T128 (tool with zero height and diameter)
G43 H128 (height offset zero)

G0 Z20 (traverse to 20mm above)

G0 X20 Y7.2 (traverse to starting point)
G0 Z5 (traverse to 5mm above part)

;; Rough Cut for Perimeter
G1 Z-2 (feed to 2mm below surface)
G2 X-1.14 Y-15.71 I-14.01 J-7.2 (A to B)
G2 X-14.01 Y-7.2 I-6.86 J3.62 (B to C)
G2 X1.14 Y15.71 I14.01 J7.2 (C to D)
G2 X14.01 Y7.2 I6.86 J-3.62 (D to A)
G0 X20 Y7.2
G1 Z-4 (feed to 2mm below surface)
G2 X-1.14 Y-15.71 I-14.01 J-7.2 (A to B)
G2 X-14.01 Y-7.2 I-6.86 J3.62 (B to C)
G2 X1.14 Y15.71 I14.01 J7.2 (C to D)
G2 X14.01 Y7.2 I6.86 J-3.62 (D to A)
G0 X20 Y7.2
G1 Z-6 (feed to 2mm below surface)
G2 X-1.14 Y-15.71 I-14.01 J-7.2 (A to B)
G2 X-14.01 Y-7.2 I-6.86 J3.62 (B to C)
G2 X1.14 Y15.71 I14.01 J7.2 (C to D)
G2 X14.01 Y7.2 I6.86 J-3.62 (D to A)
G0 X20 Y7.2
G1 Z-8 (feed to 2mm below surface)
G2 X-1.14 Y-15.71 I-14.01 J-7.2 (A to B)
G2 X-14.01 Y-7.2 I-6.86 J3.62 (B to C)
G2 X1.14 Y15.71 I14.01 J7.2 (C to D)
G2 X14.01 Y7.2 I6.86 J-3.62 (D to A)
G0 X20 Y7.2
G1 Z-9 (feed to 2mm below surface)
G2 X-1.14 Y-15.71 I-14.01 J-7.2 (A to B)
G2 X-14.01 Y-7.2 I-6.86 J3.62 (B to C)
G2 X1.14 Y15.71 I14.01 J7.2 (C to D)
G2 X14.01 Y7.2 I6.86 J-3.62 (D to A)
G0 X20 Y7.2

G0 X20 Y7.23 (traverse to starting point)

;; Finish Cut for Perimeter
F200 (set feed speed to 200mm per minute, 0.010 mm per tooth)
G1 Z-9 (feed to 9mm below part)
G2 X-1.14 Y-15.71 I-14.01 J-7.2 (A to B)
G2 X-14.01 Y-7.2 I-6.86 J3.62 (B to C)
G2 X1.14 Y15.71 I14.01 J7.2 (C to D)
G2 X14.01 Y7.2 I6.86 J-3.62 (D to A)
G0 X20 Y7.23

G0 Z20 (traverse to 20mm above)
M30 (end of program)