First article inspection in CNC Programming - Step-by-Step Execution

Concept Flow - First article inspection

Start CNC Program

↓

Load First Article

↓

Run Inspection Cycle

↓

Measure Critical Dimensions

↓

Compare Measurements to Specs

↓

If Within Tolerance

→Approve Article

↓

If Out of Tolerance

→Flag for Adjustment

↓

End Inspection

This flow shows how a CNC program runs a first article inspection by measuring and checking if the part meets specifications before approval.

Execution Sample

CNC Programming

O1000 (First Article Inspection)
G54
M06 T01
G00 X0 Y0 Z5
G01 Z-5 F100
M01 (Pause for measurement)
G00 Z5
M30

This CNC program loads the first article, moves to measurement position, pauses for inspection, then ends.

Execution Table

Step	Action	Position (X,Y,Z)	Tool	Comment
1	Program Start	(0,0,0)	None	Program begins
2	Select Work Offset G54	(0,0,0)	None	Set coordinate system
3	Tool Change M06 T01	(0,0,0)	Tool 1	Load tool 1
4	Rapid Move G00 to X0 Y0 Z5	(0,0,5)	Tool 1	Move above part
5	Linear Move G01 Z-5 F100	(0,0,-5)	Tool 1	Move down to measure
6	Optional Stop M01	(0,0,-5)	Tool 1	Pause for inspection
7	Rapid Move G00 Z5	(0,0,5)	Tool 1	Retract tool
8	Program End M30	(0,0,5)	Tool 1	End of program

💡 Program ends after M30 command, inspection pause allows measurement.

Variable Tracker

Variable	Start	After Step 4	After Step 5	After Step 7	Final
Position	(0,0,0)	(0,0,5)	(0,0,-5)	(0,0,5)	(0,0,5)
Tool	None	Tool 1	Tool 1	Tool 1	Tool 1
Program State	Start	Running	Running	Running	End

Key Moments - 3 Insights

Why does the program pause at step 6 with M01?

The M01 command pauses the program to allow the operator to measure the first article manually before continuing, as shown in execution_table row 6.

What happens if the measurements are out of tolerance?

If measurements are out of tolerance, the article is flagged for adjustment before approval, which is part of the inspection process after the program pause.

Why is the tool retracted to Z5 after measurement?

Retracting to Z5 moves the tool safely away from the part to avoid collisions, as seen in execution_table step 7.

Visual Quiz - 3 Questions

Look at the execution table, what is the tool position after step 5?

A (0,0,5)

B (0,0,0)

C (0,0,-5)

D (5,5,5)

💡 Hint

Check the Position column in execution_table row 5.

At which step does the program pause for inspection?

A Step 4

B Step 6

C Step 7

D Step 8

💡 Hint

Look for the M01 command in the Action column of execution_table.

If the tool did not retract after measurement, what step would be missing?

A Step 7

B Step 6

C Step 5

D Step 8

💡 Hint

Check which step moves the tool back up in execution_table.

Concept Snapshot

First Article Inspection in CNC:
- Load first article and tool
- Move tool to measurement position
- Pause program for manual inspection (M01)
- Retract tool after measurement
- Approve or adjust based on measurements
- End program with M30

Full Transcript

This CNC program performs a first article inspection by loading the tool and moving to the part. It pauses to allow manual measurement, then retracts the tool and ends. The flow ensures the part meets specifications before production continues.