Toolpath simulation and verification in CNC Programming - Step-by-Step Execution

Concept Flow - Toolpath simulation and verification

Load CNC Program

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Parse Toolpath Commands

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Simulate Movements Step-by-Step

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Check for Collisions or Errors

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Verify Final Shape Matches Design

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Report Issues or Confirm Success

The CNC program is loaded and parsed into toolpath commands, then simulated step-by-step to check for collisions and verify the final shape matches the design.

Execution Sample

CNC Programming

N10 G00 X0 Y0 Z5
N20 G01 Z-1 F100
N30 G01 X10 Y0 F200
N40 G01 X10 Y10
N50 G01 X0 Y10
N60 G01 X0 Y0
N70 G00 Z5

This CNC program moves the tool to start, plunges into material, cuts a square, then retracts.

Execution Table

Step	Command	Position (X,Y,Z)	Feed Rate	Action	Collision Check	Output
1	N10 G00 X0 Y0 Z5	(0,0,5)	Rapid	Move to start above material	No	Position set to (0,0,5)
2	N20 G01 Z-1 F100	(0,0,-1)	100	Plunge into material	No	Tool at cutting depth
3	N30 G01 X10 Y0 F200	(10,0,-1)	200	Cut along X axis	No	Cutting line from (0,0,-1) to (10,0,-1)
4	N40 G01 X10 Y10	(10,10,-1)	200	Cut along Y axis	No	Cutting line from (10,0,-1) to (10,10,-1)
5	N50 G01 X0 Y10	(0,10,-1)	200	Cut back along X axis	No	Cutting line from (10,10,-1) to (0,10,-1)
6	N60 G01 X0 Y0	(0,0,-1)	200	Cut back to start	No	Cutting line from (0,10,-1) to (0,0,-1)
7	N70 G00 Z5	(0,0,5)	Rapid	Retract tool	No	Tool retracted above material
8	End	-	-	Simulation complete	-	No collisions detected, shape verified

💡 All commands executed, no collisions found, final shape matches design.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	After Step 6	After Step 7	Final
Position	(undefined)	(0,0,5)	(0,0,-1)	(10,0,-1)	(10,10,-1)	(0,10,-1)	(0,0,-1)	(0,0,5)	(0,0,5)
Feed Rate	(undefined)	Rapid	100	200	200	200	200	Rapid	Rapid
Collision Detected	No	No	No	No	No	No	No	No	No

Key Moments - 3 Insights

Why does the tool move rapidly to (0,0,5) before plunging?

The rapid move (G00) positions the tool safely above the material to avoid collisions before starting the cut, as shown in execution_table step 1.

Why is the feed rate slower when plunging compared to moving above the material?

Plunging into material requires slower feed rate (F100) to avoid tool damage, unlike rapid moves above material (step 2 vs step 1 in execution_table).

How do we know no collisions occurred during the cut?

The collision check column in execution_table shows 'No' for every step, confirming safe toolpath simulation.

Visual Quiz - 3 Questions

Look at the execution table, what is the tool position after step 4?

A (10,10,-1)

B (0,10,-1)

C (10,0,-1)

D (0,0,5)

💡 Hint

Check the Position column in execution_table row for step 4.

At which step does the tool retract above the material?

A Step 6

B Step 7

C Step 2

D Step 1

💡 Hint

Look for the command with G00 and Z5 in execution_table.

If a collision was detected at step 3, what would change in the execution table?

A Position would be undefined at step 3

B Feed Rate would be zero at step 3

C Collision Check would say 'Yes' at step 3

D Output would say 'Tool retracted' at step 3

💡 Hint

Collision Check column shows if collisions occur at each step.

Concept Snapshot

Toolpath simulation loads CNC commands,
Moves tool step-by-step,
Checks collisions at each move,
Verifies final shape matches design,
Reports errors or success,
Ensures safe, accurate machining.

Full Transcript

Toolpath simulation and verification means running through CNC program commands step-by-step in a safe virtual environment. The tool moves to start position rapidly above material, then plunges slowly into cutting depth. It follows the programmed path cutting the shape, checking for collisions at each step. After finishing the cut, the tool retracts safely. The simulation confirms no collisions happened and the final shape matches the design. This process helps avoid mistakes and damage before actual machining.