Reading G-code for troubleshooting in 3D Printing - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding G-code Movement Commands

What does the G-code command G1 X50 Y25.3 F1500 instruct the 3D printer to do?

A Move the print head to X=50, Y=25.3 at a speed of 1500 mm/min

B Set the temperature to 1500°C and move to X=50, Y=25.3

C Pause the print for 1500 seconds at position X=50, Y=25.3

D Home the X and Y axes and set feed rate to 1500

💡 Hint

G1 is a command for controlled movement with specified coordinates and speed.

The G1 command moves the print head to the specified X and Y coordinates at the feed rate given by F. Here, it moves to X=50, Y=25.3 at 1500 mm/min.

📋 Factual

intermediate

Identifying Temperature Commands in G-code

Which G-code command sets the extruder temperature to 210°C?

A G1 S210

B G28 S210

C M106 S210

D M104 S210

💡 Hint

Look for the command that controls temperature settings.

M104 sets the extruder temperature to the value specified by S. Here, S210 means 210°C.

🔍 Analysis

advanced

Troubleshooting Unexpected Retraction Behavior

Given this G-code snippet:

G1 E-2 F1800
G1 X100 Y100 F3000
G1 E0 F1800

What is the purpose of the E-2 command in this context?

A It extrudes 2 mm of filament to start printing

B It retracts the filament by 2 mm to prevent oozing during travel moves

C It sets the extruder temperature to 2°C

D It moves the print head 2 mm backward on the X axis

💡 Hint

Negative E values usually mean filament retraction.

E-2 retracts filament by 2 mm to reduce stringing when the print head moves without printing.

❓ Comparison

advanced

Comparing Homing Commands

Which G-code command homes all axes of the 3D printer?

A M104

B G1

C G28

D M106

💡 Hint

Homing commands reset the position of the printer axes.

G28 homes all axes by moving them to their endstops to establish a reference position.

❓ Reasoning

expert

Diagnosing a Layer Shift from G-code

In a G-code file, you notice this sequence:

G1 X50 Y50 F3000
G1 X150 Y50 F3000
G1 X150 Y150 F3000
G1 X50 Y150 F3000
G92 X0 Y0

What is the effect of the G92 X0 Y0 command here?

A It resets the current position to X=0, Y=0 without moving the print head

B It moves the print head physically to X=0, Y=0

C It pauses the print and waits for user input

D It sets the extruder temperature to 0°C

💡 Hint

G92 changes the printer's idea of its position without moving.

G92 sets the current position to the specified coordinates, effectively resetting the coordinate system origin at the current location.