### CNC12 Lathe - Help turning a taper

Posted:

**Sun Nov 15, 2020 11:27 pm**I'm trying to turn a taper and it's not coming out right.

It should be a 1.27 degree taper, tapering from .460 to .378 over 1.85"

It's turning a taper going from .460 to .390 over 1.85"

Checked my X and Z axis and they are on track, moving the correct amount individually.

Open Loop Steppers, set to 1600 microsteps. G0602 Lathe. Ballscrews, x axis driven by toothed belt.

Turns per Inch is set as is backlash. It measures correctly both before and after turning the part.

Z0 set to end of part. X0 set to centerline with the tool being used.

What could be going on? I was told it could be because I'm not using cutter comp and my tool as a .016 radius

CODE:

; ICN_PATH = C:\icn_lath\44B Taper.lth

; CNC code generated by Intercon v4.16

; Description: Test Taper 44B

; Programmer: TAS

; Date: 15-Nov-2020

; --- Header ---

N0001 G20 ; inch measurements

:::: --- Stock Dimensions ---

:::: X- = -0.375, X+ = 0.375

:::: Z- = -3.5, Z+ = 0.0

:::: ---

G40 ; Cutter Comp Off

G28

; --- Turning ---

N0002 T0100

M9

G97 S1200.0 M4

G4 P1.0

G0 X0.75 Z0.0 T0101

X0.75 Z0.0

G90 X0.736 Z-1.849 R-0.041 G98 F10.0

G0 X0.736 Z0.0

G90 X0.722 Z-1.849 R-0.041

G0 X0.722 Z0.0

G90 X0.708 Z-1.849 R-0.041

G0 X0.708 Z0.0

G90 X0.694 Z-1.849 R-0.041

G0 X0.694 Z0.0

G90 X0.68 Z-1.849 R-0.041

G0 X0.68 Z0.0

G90 X0.666 Z-1.849 R-0.041

G0 X0.666 Z0.0

G90 X0.652 Z-1.849 R-0.041

G0 X0.652 Z0.0

G90 X0.638 Z-1.849 R-0.041

G0 X0.638 Z0.0

G90 X0.624 Z-1.849 R-0.041

G0 X0.624 Z0.0

G90 X0.61 Z-1.849 R-0.041

G0 X0.61 Z0.0

G90 X0.596 Z-1.849 R-0.041

G0 X0.596 Z0.0

G90 X0.582 Z-1.849 R-0.041

G0 X0.582 Z0.0

G90 X0.568 Z-1.849 R-0.041

G0 X0.568 Z0.0

G90 X0.554 Z-1.849 R-0.041

G0 X0.554 Z0.0

G90 X0.54 Z-1.849 R-0.041

G0 X0.54 Z0.0

G90 X0.526 Z-1.849 R-0.041

G0 X0.526 Z0.0

G90 X0.512 Z-1.849 R-0.041

G0 X0.512 Z0.0

G90 X0.498 Z-1.849 R-0.041

G0 X0.498 Z0.0

G90 X0.484 Z-1.849 R-0.041

G0 X0.484 Z0.0

G90 X0.47 Z-1.849 R-0.041

G0 X0.47 Z0.0

G90 X0.462 Z-1.849 R-0.041

G0 X0.378 Z0.0

G1 X0.46 Z-1.85

X0.75 Z-1.85

G0 X0.75 Z0.0

; --- End of Program ---

N0003 G28 T0100

M5

M9

G40

; End of Program

It should be a 1.27 degree taper, tapering from .460 to .378 over 1.85"

It's turning a taper going from .460 to .390 over 1.85"

Checked my X and Z axis and they are on track, moving the correct amount individually.

Open Loop Steppers, set to 1600 microsteps. G0602 Lathe. Ballscrews, x axis driven by toothed belt.

Turns per Inch is set as is backlash. It measures correctly both before and after turning the part.

Z0 set to end of part. X0 set to centerline with the tool being used.

What could be going on? I was told it could be because I'm not using cutter comp and my tool as a .016 radius

CODE:

; ICN_PATH = C:\icn_lath\44B Taper.lth

; CNC code generated by Intercon v4.16

; Description: Test Taper 44B

; Programmer: TAS

; Date: 15-Nov-2020

; --- Header ---

N0001 G20 ; inch measurements

:::: --- Stock Dimensions ---

:::: X- = -0.375, X+ = 0.375

:::: Z- = -3.5, Z+ = 0.0

:::: ---

G40 ; Cutter Comp Off

G28

; --- Turning ---

N0002 T0100

M9

G97 S1200.0 M4

G4 P1.0

G0 X0.75 Z0.0 T0101

X0.75 Z0.0

G90 X0.736 Z-1.849 R-0.041 G98 F10.0

G0 X0.736 Z0.0

G90 X0.722 Z-1.849 R-0.041

G0 X0.722 Z0.0

G90 X0.708 Z-1.849 R-0.041

G0 X0.708 Z0.0

G90 X0.694 Z-1.849 R-0.041

G0 X0.694 Z0.0

G90 X0.68 Z-1.849 R-0.041

G0 X0.68 Z0.0

G90 X0.666 Z-1.849 R-0.041

G0 X0.666 Z0.0

G90 X0.652 Z-1.849 R-0.041

G0 X0.652 Z0.0

G90 X0.638 Z-1.849 R-0.041

G0 X0.638 Z0.0

G90 X0.624 Z-1.849 R-0.041

G0 X0.624 Z0.0

G90 X0.61 Z-1.849 R-0.041

G0 X0.61 Z0.0

G90 X0.596 Z-1.849 R-0.041

G0 X0.596 Z0.0

G90 X0.582 Z-1.849 R-0.041

G0 X0.582 Z0.0

G90 X0.568 Z-1.849 R-0.041

G0 X0.568 Z0.0

G90 X0.554 Z-1.849 R-0.041

G0 X0.554 Z0.0

G90 X0.54 Z-1.849 R-0.041

G0 X0.54 Z0.0

G90 X0.526 Z-1.849 R-0.041

G0 X0.526 Z0.0

G90 X0.512 Z-1.849 R-0.041

G0 X0.512 Z0.0

G90 X0.498 Z-1.849 R-0.041

G0 X0.498 Z0.0

G90 X0.484 Z-1.849 R-0.041

G0 X0.484 Z0.0

G90 X0.47 Z-1.849 R-0.041

G0 X0.47 Z0.0

G90 X0.462 Z-1.849 R-0.041

G0 X0.378 Z0.0

G1 X0.46 Z-1.85

X0.75 Z-1.85

G0 X0.75 Z0.0

; --- End of Program ---

N0003 G28 T0100

M5

M9

G40

; End of Program