Machine axes (X, Y, Z for milling) in CNC Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the resulting position after this move command?

Given the initial tool position at X0 Y0 Z0, what is the tool position after executing the command G01 X10 Y-5 Z3 F100?

CNC Programming

Initial position: X0 Y0 Z0
Command: G01 X10 Y-5 Z3 F100

A X0 Y0 Z0

B X10 Y-5 Z3

C X10 Y0 Z3

D X0 Y-5 Z3

💡 Hint

G01 moves the tool in a straight line to the specified coordinates.

The G01 command moves the tool linearly to the specified X, Y, and Z coordinates. So the final position is exactly X10 Y-5 Z3.

🧠 Conceptual

intermediate

Which axis controls the vertical movement in milling?

In a standard 3-axis milling machine, which axis moves the tool up and down?

A Z axis

B Y axis

C X axis

D A axis

💡 Hint

Think about the 3D coordinate system: X and Y are horizontal directions.

The Z axis controls vertical movement (up and down) in milling machines.

📝 Syntax

advanced

What error occurs with this CNC command?

What error will this CNC command produce? G01 X10 Y Z5

CNC Programming

G01 X10 Y Z5

A No error, moves to X10 Y0 Z5

B Runtime error: tool collision

C Syntax error due to missing Y coordinate value

D Warning: feed rate missing

💡 Hint

Every axis coordinate must have a number after the letter.

The Y axis coordinate is missing a value, causing a syntax error.

🚀 Application

advanced

How many unique positions does this program move through?

Given this CNC program snippet, how many unique positions does the tool move to?

G00 X0 Y0 Z0
G01 X5 Y5 Z-1
G01 X5 Y5 Z-1
G01 X10 Y0 Z-1
G00 X0 Y0 Z0

A 2

B 4

C 5

D 3

💡 Hint

Count unique coordinate sets ignoring repeated positions.

Positions are: (0,0,0), (5,5,-1), (10,0,-1). The second move to (5,5,-1) is repeated, so total unique positions are 3.

🔧 Debug

expert

Why does this CNC program cause unexpected Z-axis movement?

This CNC program snippet causes the tool to plunge unexpectedly deep on the Z axis. What is the cause?

G00 X0 Y0 Z5
G01 X10 Y10 Z-5 F200
G01 X20 Y20 Z-10
G00 Z5

A Z coordinate in second G01 is lower than intended causing deep plunge

B G00 command moves too fast causing tool to crash

C Missing feed rate on the second G01 causes default slow plunge

D Tool length offset not set causing wrong Z reference

💡 Hint

Look carefully at the Z values in each move command.

The second G01 command moves the tool to Z-10, which is deeper than the previous Z-5, causing the unexpected plunge.