Combining arcs and lines for contours in CNC Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to move the tool in a straight line to X10 Y10.

CNC Programming

G01 X[1] Y10

Drag options to blanks, or click blank then click option'

A10

B5

C0

D20

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong coordinate value like 20 or 5.

Confusing G01 with arc commands.

The command G01 moves the tool in a straight line to the specified coordinates. Here, X10 moves the tool to X=10.

2fill in blank

medium

Complete the code to create a clockwise arc to X20 Y20 with center offset I5 J0.

CNC Programming

G02 X20 Y20 I[1] J0

Drag options to blanks, or click blank then click option'

A0

B-5

C10

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using zero or negative values for I when positive is needed.

Mixing up I and J values.

I5 means the arc center is offset 5 units in the X direction from the start point.

3fill in blank

hard

Fix the error in the code to create a counterclockwise arc to X30 Y30 with center offset I0 J10.

CNC Programming

G03 X30 Y30 I[1] J10

Drag options to blanks, or click blank then click option'

A10

B0

C-10

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-zero value for I when zero is needed.

Confusing I and J values.

I0 means no offset in X direction, which matches the problem statement.

4fill in blank

hard

Fill both blanks to complete the code for a contour: a line to X40 Y40, then a clockwise arc to X50 Y50 with center offset I5 J{{BLANK_2}}.

CNC Programming

G01 X[1] Y40
G02 X50 Y50 I5 J[2]

Drag options to blanks, or click blank then click option'

A40

B0

C5

D-5

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong X coordinate for the line move.

Using zero or negative value for J when positive is needed.

First line moves to X40 Y40, then arc center offset J5 matches the arc center offset.

5fill in blank

hard

Fill all three blanks to create a contour dictionary with keys as points and values as commands, filtering only commands with radius > 5.

CNC Programming

contour = [1]: [2] for [3], cmd in commands.items() if cmd['radius'] > 5}

Drag options to blanks, or click blank then click option'

Apoint

Bcmd

Dcommand

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong variable names for keys or values.

Confusing the iteration variables.

The dictionary comprehension uses point as key, cmd as value, and iterates over point, cmd pairs.

Practice

1. Which G-code command is used to move the tool in a straight line when combining arcs and lines for contours?

easy

A. G01

B. G02

C. G03

D. G00

Solution

1. Step 1: Understand G-code commands for movement

   G01 is the command for linear interpolation, which moves the tool in a straight line.

2. Step 2: Differentiate from arc commands

   G02 and G03 are used for clockwise and counterclockwise arcs, respectively, while G00 is rapid positioning without cutting.

3. Final Answer:

   G01 -> Option A

4. Quick Check:

   Straight line move = G01 [OK]

Hint: Remember: G01 = line, G02/G03 = arcs [OK]

Common Mistakes:

• Confusing G01 with G02 or G03
• Using G00 for cutting moves
• Mixing arc commands for straight lines

2. Which of the following is the correct syntax to program a clockwise arc from the current position to X10 Y10 with center offset I5 J0?

easy

A. G02 X10 Y10 I5 J0

B. G03 X10 Y10 I5 J0

C. G01 X10 Y10 I5 J0

D. G00 X10 Y10 I5 J0

Solution

1. Step 1: Identify arc direction commands

   G02 is used for clockwise arcs, G03 for counterclockwise arcs.

2. Step 2: Check parameters for arc center

   I and J specify the center offset relative to the start point, which is correct here.

3. Final Answer:

   G02 X10 Y10 I5 J0 -> Option A

4. Quick Check:

   Clockwise arc = G02 [OK]

Hint: G02 = clockwise arc, G03 = counterclockwise arc [OK]

Common Mistakes:

• Using G03 for clockwise arcs
• Using G01 or G00 with I and J parameters
• Forgetting I and J for arc centers

3. What is the output position of the tool after executing the following G-code sequence starting at X0 Y0?

G01 X10 Y0
G02 X10 Y10 I0 J5

medium

A. X10 Y5

B. X0 Y10

C. X10 Y10

D. X5 Y10

Solution

1. Step 1: Execute the linear move

   G01 X10 Y0 moves the tool straight from X0 Y0 to X10 Y0.

2. Step 2: Execute the clockwise arc

   G02 X10 Y10 I0 J5 draws a clockwise arc from X10 Y0 to X10 Y10 with center offset 0 in X and 5 in Y, forming a quarter circle.

3. Final Answer:

   X10 Y10 -> Option C

4. Quick Check:

   Arc ends at X10 Y10 [OK]

Hint: Arc ends at specified X and Y coordinates [OK]

Common Mistakes:

• Confusing arc center offsets
• Assuming arc ends at center point
• Ignoring the final X and Y in arc command

4. Identify the error in this G-code snippet intended to create a smooth contour combining lines and arcs:

G01 X5 Y5
G02 X10 Y10 I5 J0
G03 X15 Y5 I5 J-5

medium

A. Missing G00 command before arcs

B. Incorrect use of I and J values for arc centers

C. Using G03 instead of G02 for clockwise arc

D. No error, code is correct

Solution

1. Step 1: Analyze arc center offsets

   For the first arc G02 X10 Y10 I5 J0, the center offset I5 J0 is correct relative to start X5 Y5.

2. Step 2: Check second arc offsets

   G03 X15 Y5 I5 J-5 is suspicious because the center offset I5 J-5 does not correctly define a smooth arc from X10 Y10 to X15 Y5.

3. Final Answer:

   Incorrect use of I and J values for arc centers -> Option B

4. Quick Check:

   Arc center offsets must match start/end points [OK]

Hint: Verify I and J match arc start/end points [OK]

Common Mistakes:

• Assuming any I/J values work
• Confusing clockwise and counterclockwise arcs
• Forgetting arcs need correct center offsets

5. You want to program a contour that starts at X0 Y0, moves straight to X20 Y0, then follows a counterclockwise arc to X20 Y20 with center offset I0 J10, and finally moves straight back to X0 Y20. Which sequence of G-code commands correctly achieves this?

hard

A. G01 X20 Y0
G02 X20 Y20 I0 J10
G01 X0 Y20

B. G01 X20 Y0
G03 X20 Y20 I10 J0
G01 X0 Y20

C. G00 X20 Y0
G03 X20 Y20 I0 J10
G00 X0 Y20

D. G01 X20 Y0
G03 X20 Y20 I0 J10
G01 X0 Y20

Solution

1. Step 1: Move straight from start to X20 Y0

   Use G01 X20 Y0 for a linear cut from X0 Y0 to X20 Y0.

2. Step 2: Program counterclockwise arc to X20 Y20

   G03 is for counterclockwise arcs; center offset I0 J10 matches the arc center 10 units above start point.

3. Step 3: Move straight back to X0 Y20

   Use G01 X0 Y20 for a linear move back along Y axis.

4. Final Answer:

   G01 X20 Y0 G03 X20 Y20 I0 J10 G01 X0 Y20 -> Option D

5. Quick Check:

   Line + CCW arc + line = sequence B [OK]

Hint: Use G03 for CCW arcs with correct I/J offsets [OK]

Common Mistakes:

• Using G02 instead of G03 for CCW arc
• Wrong I/J values for arc center
• Using G00 for cutting moves