CNC CNC Mill Setup & Operation 2

Question 1

When indicating a vise jaw parallel to the X-axis on a CNC mill, which tool is most commonly used?

Accepted Answer

Dial test indicator (DTI)

Answer

A dial test indicator is swept along the jaw face while adjusting the vise until runout is within tolerance.

Question 2

A CNC milling program calls G43 H02. What does H02 specify?

Accepted Answer

The tool length offset register 2

Answer

G43 activates tool length compensation and H02 selects the value stored in offset register number 2.

Question 3

Which G-code cancels cutter radius compensation (CRC)?

Accepted Answer

G40

Answer

G40 cancels cutter radius compensation, while G41 is left compensation and G42 is right compensation.

Question 4

What is the purpose of a pecking cycle (G83) in CNC milling?

Accepted Answer

Drill deep holes with periodic chip-clearing retracts

Answer

G83 is the deep-hole peck-drilling cycle that retracts to the R-plane between each peck to clear chips and allow coolant penetration.

Question 5

On a Fanuc-style control, what does the address F represent in a milling program?

Accepted Answer

Feed rate in inches or mm per minute (or per revolution)

Answer

The F word specifies feed rate, interpreted as per-minute (G94) or per-revolution (G95) depending on the active feed mode.

(CNC) Computer Numerical Control Machinist Technical Practice Test