CNC CNC Lathe Turning Operations 3

Question 1

In CNC lathe programming, G96 activates:

Accepted Answer

Constant surface speed (CSS) mode

Answer

G96 enables Constant Surface Speed mode, where the controller automatically adjusts spindle RPM as the tool moves to different diameters.

Question 2

What is the function of the G70 finishing cycle on a Fanuc-style CNC lathe?

Accepted Answer

Performs a finishing pass along a defined profile

Answer

G70 is the finishing cycle that traces the part profile defined in the G71 or G72 rough turning sequence to remove the finishing allowance.

Question 3

A negative rake angle on a turning insert:

Accepted Answer

Provides a stronger cutting edge

Answer

A negative rake angle creates a stronger, more supported cutting edge, making it suitable for interrupted cuts and hard materials.

Question 4

What does 'dwell' (G04) accomplish in a CNC lathe program?

Accepted Answer

Pauses axis motion for a specified time or revolutions

Answer

G04 causes the machine to pause all axis motion for a programmed time (seconds) or spindle revolutions, useful for cleaning up grooves or facing.

Question 5

When programming an internal boring operation, the X-axis values are:

Accepted Answer

Larger as the bore diameter increases

Answer

In boring, moving to a larger X value increases the bore diameter because the tool moves away from the spindle centerline.

(CNC) Computer Numerical Control Machinist Technical Practice Test