FANUC 5-axis Machining Program and Detailed Analysis

This article presents a five-axis machining program adapted for the FANUC 0i-MF system. It targets titanium alloy TC4 curved surface parts (similar to a simplified model of an engine blade) used in the aerospace field, employing five-axis linkage (A-axis and C-axis oscillation). Combining the cutting parameters and tool selection mentioned earlier, the program can be directly imported into the machine tool for debugging. The following is the complete program and a detailed technical explanation line by line, balancing professionalism with practicality.

I. Machining Prerequisites (Required Reading, Ensure Program Compatibility)

Equipment Model: Five-axis CNC machine tool (DMU 50 type), A-axis swing range ±120°, C-axis swing range ±180°, positioning accuracy 0.002mm;
Tool Parameters: Ball end mill (PCD material, Φ10mm, cutting length 20mm, cutting edge radius 0.2mm), tool length compensation number H01, radius compensation number D01;
Machining Material: Titanium alloy TC4 (hardness HRC30-35), part coordinate system (G54) established at the center of the part’s reference surface, Z-axis zero point is the upper surface of the part;
Cutting Parameters: Spindle speed 800rpm, feed rate 0.08mm/r, depth of cut 0.1mm, cooling method is low-temperature cooling (-50℃);
Machining Method: Five-axis linkage surface finishing, using helical feed, stepover 0.15mm, to avoid interference.

II. Complete 5-Axis Machining Program (FANUC 0i-MF System)

O0002 (Main Program for 5-Axis Surface Machining)

G21 G90 G94 G40 G49 G80 (Program initialization, setting metric units, absolute coordinates, feed rate (mm/min), canceling tool compensation)

G54 X0 Y0 Z50 A0 C0 (Calling the G54 coordinate system, quickly positioning to a safe position, A/C axes return to zero)

M03 S800 (Spindle forward rotation, speed 800rpm, suitable for machining TC4 titanium alloy)

G43 H01 Z20 (Calling tool length compensation H01, quickly moving to the Z20mm position, close to the workpiece)

G01 Z5 F500 (Uniformly descending to the Z5mm position, feed rate 500mm/min, avoiding impact)

C45.0 (C-axis swinging to 45°, adjusting the machining angle, avoiding tool interference)

A-30.0 (A-axis swings to -30° to adapt to the surface machining angle and ensure tool cutting posture) G41 D01 X10 Y10 F100 (Call tool radius compensation D01, move to the surface starting cutting position, feed rate 100mm/min)

#1=0 (Set variable #1 for helical feed cycle counting)

#2=360 (Set variable #2, total helical angle 360°)

#3=5 (Set variable #3, feed angle per helical revolution 5°)

WHILE[#1 LE #2] DO1 (Loop instruction, execute the loop body when #1≤#2)

G01 X[10+#10.05] Y[10+#10.05] Z[5-#1*0.0139] A-30 C[45+#1] F0.08 (Five-axis linkage cutting, X/Y axis helical feed, Z axis synchronous descent, A/C axis maintain posture) #1=#1+#3 (Variable #1 is accumulated, increasing by 5° each time, completing one helical cut per revolution)

END1 (Loop ends, completing 360° helical surface machining)

G40 X0 Y0 (Cancel tool radius compensation, move to a safe position)

A0 C0 (A/C axis returns to zero, restoring initial posture)

G00 Z50 (Rapidly retract the tool to a safe height of Z50mm)

M05 (Spindle stops)

M09 (Cooling off)

M30 (Program ends, reset, return to the beginning of the program)

III. Detailed Analysis of the Program Line by Line (Practical Level, Easy to Understand and Remember)

1. Program Initialization Section (Core: Clears redundant settings to ensure stable program operation)

O0002: Program number, used to distinguish different machining programs. The FANUC system program number range is O0001-O9999. It is recommended to number them by part type for easier management.

G21: Sets the metric unit (mm). CNC machining defaults to metric, corresponding to the unit of the titanium alloy machining parameters mentioned earlier, avoiding unit confusion.

G90: Absolute coordinate programming. All coordinate values ​​are based on the zero point of the G54 coordinate system for precise positioning, suitable for curved surface machining.

G94: Feed rate unit is set to mm/min (feed per minute), which does not conflict with F0.08 (feed per revolution) mentioned later; the system automatically recognizes it.

G40, G49, G80: respectively cancel tool radius compensation, tool length compensation, and fixed cycle to avoid collisions caused by residual tool compensation/cycles from the previous program.

2. Coordinate System and Safety Positioning Section (Core: Interference Avoidance, Precise Positioning)

G54 X0 Y0 Z50 A0 C0: Calls the pre-established G54 part coordinate system (zero point at the center of the part’s reference surface), positions the X/Y/Z axes to a safe height of (0,0,50) mm, and returns the A-axis (oscillating axis) and C-axis (rotational axis) to zero, ensuring no interference in the initial posture;

M03 S800: Spindle rotates forward at 800 rpm, strictly matching the finishing speed of titanium alloy TC4 (as specified in Table 2.3 above, to avoid excessive speed leading to tool wear);

G43 H01 Z20: Calls tool length compensation H01 (the actual tool length is pre-input into the machine tool, error ≤0.005 mm), quickly moves to Z20 mm, close to the part but not in contact, preparing for subsequent uniform feed;

G01 Z5 F500: Descends to Z5 mm at a uniform speed of 500 mm/min, avoiding impact on the part from rapid movement (G00), protecting the tool and workpiece surface.

3. Five-Axis Attitude Adjustment Section (Core: Adapting to Curved Surface Cutting, Avoiding Interference)

C45.0: The C-axis (table rotation axis) swings clockwise by 45°, adjusting the workpiece rotation angle to ensure the curved surface cutting surface and tool axis form a reasonable angle.

A-30.0: The A-axis (spindle swing axis) swings downwards by 30°, adjusting the tool cutting attitude to ensure the ball end mill’s cutting edge fits the curved surface, avoiding overcutting or undercutting. This is the core difference between five-axis and three-axis machining (multi-angle adjustment of cutting attitude is possible).

4. Tool Compensation Callup and Cutting Preparation Section (Core: Precise Compensation, Ensuring Dimensional Accuracy)

G41 D01 X10 Y10 F100: Calls tool radius compensation D01 (inputs the actual radius of the ball end mill, including the cutting edge radius of 0.2mm), moves to the starting cutting position on the curved surface (X10, Y10), feed rate 100mm/min, slow entry to avoid impact.

5. Five-Axis Linkage Cyclic Cutting Section (Core: Core of Surface Machining, Key Analysis)

#1=0, #2=360, #3=5: Set 3 variables: #1 is the initial value of the cycle count, #2 is the total angle of the helix (360°, i.e., one complete revolution), and #3 is the feed angle per revolution (5°, the smaller the angle, the smoother the surface);

WHILE[#1 LE #2] DO1: FANUC system cycle command, meaning “when #1≤#2, execute the cycle body after DO1”, realizing continuous helix cutting;

G01 X[10+#10.05] Y[10+#10.05] Z[5-#1*0.0139] A-30 C[45+#1] F0.08:
X/Y axis: Feed according to the formula “10 + #1 * 0.05”. For every 5° increase in #1, the X/Y axis increases by 0.25mm, forming a spiral trajectory.
Z axis: Simultaneously descends according to the formula “5 – #1 * 0.0139”. As #1 increases from 0 to 360°, the Z axis decreases from 5mm to 0mm, completing the surface cutting depth.
A-30, C[45 + #1]: The A axis remains at -30°, while the C axis increases synchronously with #1 (increasing by 360° per revolution), achieving five-axis linkage and ensuring the tool always conforms to the surface.
F0.08: 0.08mm feed per revolution, suitable for titanium alloy finishing, avoiding surface roughness caused by excessive feed.
#1 = #1 + #3: After each cycle, #1 increases by 5° until #1 = 360°, ending the cycle.
END1: Cycle terminates, completing the five-axis linkage finishing of the entire surface. 6. Program End Segment (Core: Safe Tool Retraction, Protecting Equipment and Workpiece)

G40 X0 Y0: Cancel tool radius compensation, move to (0,0) position to avoid interference caused by tool compensation residue during retraction;

A0 C0: A-axis and C-axis return to zero, restoring the initial posture for easy part handling and program restart;

G00 Z50: Quickly retract the tool to a safe height of Z50mm, away from the workpiece to avoid collision;

M05: Spindle stops rotating, ending cutting;

M09: Turn off the cooling system (low-temperature cooling) to save energy;

M30: Program ends, machine tool resets, automatically returns to the beginning of the program for easy reuse during batch processing. IV. Practical Precautions (Key Reminders to Avoid Malfunctions)

Before importing the program, verify the compensation values ​​of H01 (tool length) and D01 (tool radius) on the machine tool. The error must be ≤0.005mm, otherwise it will lead to dimensional deviations.

When running the program for the first time, run it dry (without tools) to verify that there is no interference between the A/C axis swings, then perform a trial cut (single-circle cycle), verify the surface dimensions, and then proceed with batch processing.

During processing, monitor the cutting temperature (≤200℃) and cutting force (≤3000N) in real time. If the thresholds are exceeded, stop the machine immediately and adjust the cutting parameters.

If the surface accuracy is not up to standard (Ra＞0.4μm), reduce #3 (feed angle per revolution) to 3°, or reduce the feed rate to 0.06mm/r.

Variables #1, #2, and #3 in the program can be adjusted according to the surface dimensions of the part. For example, if the total height of the surface increases, the coefficient (0.0139) in the Z-axis descent formula can be modified.