Comprehensive Guide: Engraving Letters and Characters with Mitsubishi CNC Machines
Introduction
This FAQ addresses common questions about text engraving capabilities on Mitsubishi CNC machines (including M700V Series, M80 Series, etc.). Designed for machinists, programmers, and shop owners, we clarify feasibility, setup best practices, troubleshooting, and advanced techniques. Our answers combine Mitsubishi-specific protocols with industry standards to help you achieve precise, efficient engraving results.
Section 1: Feasibility and Core Capabilities
Q1: Can Mitsubishi CNC systems engrave letters, numbers, and symbols reliably?
A1. Core Answer:
Yes, all modern Mitsubishi CNC systems (e.g., M700V, M800) can precisely engrave text using standard G-code commands or dedicated cycles.
A2. Explanation & Principles:
Engraving leverages the same core functions as contour milling. You use:
- G01 Linear Interpolation: For standard fonts.
- G02/G03 Circular Interpolation: For curved characters.
- Custom MACRO Programs: For complex logos or batch processing. Compatibility includes .TTF fonts converted via CAD/CAM software. Note: Thin-stroke fonts (<0.3mm) require micro-diameter tools.
A3. Recommendations:
- Verify spindle runout tolerance (<0.005mm) for fine details.
- Use high-speed steel (HSS) or carbide PCB engraving tools for non-ferrous metals. (Refer to our [Engraving Tool Selection Guide] for material-specific recommendations.)
Q2: What file formats does Mitsubishi CNC accept for engraving designs?
A1. Core Answer:
.NC (G-code), .EIA, and .MIN files are native. Vector formats like .DXF or .DWG require CAM conversion first.
A2. Explanation & Principles:
Mitsubishi CNCs process ISO-standard G-code. Complex designs from Adobe Illustrator/SolidWorks must be:
- Traced into toolpaths by CAM software (e.g., Mastercam, Fusion 360).
- Post-processed using Mitsubishi-specific machine definitions to avoid unsupported codes.
A3. Recommendations:
- Enable “Geometric Element Library” on M800 controls to store common symbols for rapid recall. (Insert "Text-to-GCode Conversion Workflow" diagram here.)
Section 2: Programming and Setup
Q3: How do I program engraved text without CAM software?
A1. Core Answer:
Manual G-code using absolute coordinates, or leverage Mitsubishi’s Canned Cycle (G970 Engraving Function).
A2. Explanation & Principles:
Example for letter "A" (2mm height):
G90 G54 G0 X0 Y0 Z5.
G43 H01 Z50. (Tool length comp)
G97 S8000 M03 (Spindle start)
G0 Z1.
G01 Z-0.2 F100.
G01 X5 Y20 F500. (Start Point)
G01 X10 Y0.
G01 X15 Y20.
G01 X12.5 Y12.5.
G01 X7.5 Y12.5.
G0 Z5.
A3. Recommendations:
- Simplify with G970:
G970 P5 R0.2 F200 S8000;(P=Character Height, R=Depth). - Validate programs offline using Mitsubishi’s Virtual CNC Simulator.
Q4: What depth, feed rate, and cutter settings work best?
A1. Core Answer:
Depth: ≤0.5mm per pass. RPM: 8,000–15,000. Feed: 300–800 mm/min (dependent on material hardness).
| A2. Explanation & Principles:
Minimize deflection with these tool/material pairings: |
Material | Tool Type | Diameter | RPM | Feed (mm/min) |
|---|---|---|---|---|---|
| Aluminum | 2-flute carbide | 0.8mm | 15,000 | 600 | |
| Stainless | Carbide PCB | 1mm | 9,000 | 350 | |
| Plastics | V-bit HSS | 60° | 7,000 | 800 |
A3. Recommendations:
- Always perform on-material spindle warm-up for thermal stability.
- Fine Pitch Ball Screw-equipped machines reduce vibration critical for small fonts.
Section 3: Troubleshooting
Q5: Why do corners appear rounded or letters blur?
A1. Core Answer:
Excessive tool deflection, incorrect compensation, or low servo responsiveness.
A2. Explanation & Principles:
- Corner Rounding: Caused by high feed rates exceeding servo capacity (e.g., rapid direction changes).
- Burring/Blurring: Dull tools or insufficient chip evacuation. Apply MIST coolant with compressed air assist.
Mitsubishi-specific fix: Adjust SV009 (Servo Low-Pass Filter) ÷ Reduce to improve tracking precision.
A3. Recommendations:
- Enable High-Precision Contour Control (HPCC) on M700V+/M80 systems.
- Carbide micro-engravers must be replaced after 30+ hours runtime. (Refer to our [Servo Tuning Guide] for axis optimization.)
Q6: Can "Script Fonts" be engraved without distortion?
A1. Core Answer:
Yes, with synchronized Z-axis interpolation (requires 4-axis capability) or CAM-generated point-to-point paths.
A2. Explanation & Principles:
Cursive fonts need continuous Z-axis modulation to maintain constant tool pressure. On Mitsubishi 3-axis machines:
- Convert text to segmented helical arcs in CAM.
- Use G187 E2 (Smoothing mode) to minimize segmented-path vibration.
A3. Recommendations:
- For dual-plane cursive (e.g., cylindrical parts), prioritize Mitsubishi C80/C70 series with Rotary Table Sync Control. (Insert "3D-Surface Engraving Toolpath" schematic here.)
Section 4: Advanced Applications
Q7: Can I automate engraving unique serial numbers?
A1. Core Answer:
Yes, via Mitsubishi’s "MACRO Variable Programming" and External Data Input.
A2. Explanation & Principles:
Use #500+ variables for dynamic text:
N100 G970 P5 R0.2 F400
G74 X50 Y50 (POSITION)
M98 P9001 (#502 DATA ENGRAVE SUBPROGRAM)
IF [#501 LT 100] GOTO100
A3. Recommendations:
- Integrate barcode scanners via RS-232 port for direct M-code triggering. (Refer to our [MACRO Programming Handbook] for syntax details.)
Section 5: Maintenance for Consistent Engraving Quality
Q8: How often should I recalibrate axes for micro-engraving?
A1. Core Answer:
Bi-weekly linear scale verification and quarterly ball screw backlash compensation.
A2. Explanation & Principles:
Tolerances ≤0.015mm are critical. Standard Mitsubishi protocols include:
- Laser interferometer checks on X/Y/Z (±0.005mm tolerance).
- Servo Auto-Tuning after replacing axes motors.
A3. Recommendations:
- Document calibration results in Mitsubishi Maintenance Log Software.
- Replace thrust bearings if backlash exceeds 10µm.
Summary and Next Steps
Mitsubishi CNC systems offer industrial-grade text engraving versatility. Key success factors include precise CAM post-processing, tool/material alignment, and leveraging Mitsubishi-specific cycles (G970) or MACROs. For unresolved challenges:
- Download our Fine Engraving Parameters Handbook.
- Contact Mitsubishi Tech Support with error codes + material/tool specs.
- Attend Mitsubishi’s Advanced Programming Training for complex applications.
[Summary by Senior Engineer]
Engraving precision hinges on servo rigidity and tool integrity. Avoid path distortion through dynamic feed adjustments and quarterly thermal compensation calibration. Critical preventative action: Always dry-run new font programs at 50% speed to validate toolpaths before material contact.
