1. ## Student

Hi!, I'm a student just learning begining CNC lathe programming and I am having a certain amount of trouble. The problem is that I have been given two lines of code :N250 G01 X.875 Z-.518 F.012 and N260 X1.025 Z-.593. We are are being taught to calculate corner breaks long hand without using G42/G41. I am asked to deduce from these lines of code the angle (per side) of the taper being machined. The tnr is .031. I am also given the selection of 30, 25, 45, or 63 degrees. Can anyone show me how this is done?? If this is the wrong forum for this type of question, please forgive me and kindly forward me to the proper one. Thanks.

2. The slope (or angle) of the toolpath is independent of the tool nose radius.

The nose radius will effect the size of a chamfer or corner break.

Anyway, to calculate the angle:

angle = arctangent(rise / run)

= arctangent (change in X / change in Z)

= arctangent( ((1.025 - .875)/2) / (-.593 - -.518) )
x is diameter value, divide by 2 for radial distance

= arctangent (-1)

= -45 degrees

3. Originally Posted by highmikebart
Hi!, I'm a student just learning begining CNC lathe programming and I am having a certain amount of trouble. The problem is that I have been given two lines of code :N250 G01 X.875 Z-.518 F.012 and N260 X1.025 Z-.593. We are are being taught to calculate corner breaks long hand without using G42/G41. I am asked to deduce from these lines of code the angle (per side) of the taper being machined. The tnr is .031. I am also given the selection of 30, 25, 45, or 63 degrees. Can anyone show me how this is done?? If this is the wrong forum for this type of question, please forgive me and kindly forward me to the proper one. Thanks.
1.025-.875=.150
.593-.518=.075

X moves twice as much as Z so it is a true 45 degree angle.

4. Originally Posted by Eurisko
The slope (or angle) of the toolpath is independent of the tool nose radius.

The nose radius will effect the size of a chamfer or corner break.

Anyway, to calculate the angle:

angle = arctangent(rise / run)

= arctangent (change in X / change in Z)

= arctangent( ((1.025 - .875)/2) / (-.593 - -.518) )
x is diameter value, divide by 2 for radial distance

= arctangent (-1)

= -45 degrees
I want to thank you very much for the help. Your response was much appreciated. Thanks again!

• Originally Posted by theemudracer
1.025-.875=.150
.593-.518=.075

X moves twice as much as Z so it is a true 45 degree angle.