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Week 03 – Computer Controlled Cutting

Group Assignment – Laser Cutter Characterization

Team Members: Tamrat Teklemarkos & Rico Kanthatham

Objective

The goal of the group assignment was to characterize the laser cutter and understand its capabilities, limitations, and cutting behavior.

This includes studying how different parameters influence cutting quality and accuracy:

  • Focus
  • Power
  • Speed
  • Frequency
  • Kerf
  • Joint clearance

These parameters determine how precisely the laser cutter can fabricate parts and are essential when designing press-fit constructions.

Laser Cutter Used

GS Laser System GS6090PU

Machine Model: GS Laser System GS6090PU Laser Type: CO₂ Laser Power: 100W Control Software: RDWorks V8.01

GS Laser System

The GS laser system is an industrial-grade CO₂ laser machine used to cut and engrave non-metal materials.

Typical materials processed:

  • MDF
  • Plywood
  • Acrylic
  • Cardboard
  • Leather

The machine uses a 10,600 nm wavelength CO₂ laser beam which is highly effective for cutting organic materials.

Laser Cutter Workflow

Typical cutting procedure:

  1. Turn ON the laser cutter
  2. Check air compressor and water cooling system
  3. Place and secure material on the cutting bed
  4. Focus the laser on the material surface
  5. Set the XY origin point
  6. Assign colors for cut and engrave paths
  7. Send design to RDWorks V8.01 Job Control
  8. Assign power and speed parameters
  9. Turn ON air assist
  10. Close the lid and enable fume extraction
  11. Run the job while monitoring continuously

Laser Cutter Safety Rules

Laser cutting involves high heat and fire risk, so safety is critical.

Safety rules followed:

  • Keep fire extinguisher and fire blanket nearby
  • Never run the machine with the cover open
  • Never look directly at the laser beam
  • Ensure water cooling system is ON
  • Ensure ventilation and air assist are active
  • Never leave the machine unattended

  • If fire occurs:

  • Immediately turn OFF the machine

  • Use fire suppression tools

Laser safety

Laser Cutter Characterization

The purpose of characterization is to understand:

  • What the machine can and cannot do
  • How precise it is
  • How cutting parameters affect quality

Important parameters tested:

  • Power
  • Speed
  • Focus
  • Kerf
  • Joint clearance

Parameter adjustment

Determining Cutting Parameters

We tested several combinations of power and speed on scrap MDF.

Power Speed Result
100% 10 mm/s No proper cut due to damaged lens
40% 80 mm/s Engraving only
30% 50 mm/s Clean cut

Observations

  • Higher speed → shallower cuts
  • Lower speed → deeper cuts
  • Excessive power → burned edges

The optimal setting for MDF was:

Power: 30% Speed: 50 mm/s

This produced clean edges with minimal burning.

Kerf Measurement

To determine the laser kerf, we cut a 20 mm × 20 mm square test piece.

Kerf represents the material removed by the laser beam during cutting.

Procedure

  1. Draw a 20 mm square in Inkscape
  2. Cut the square using the laser cutter
  3. Measure the inner hole and outer piece

Measurement Results

Measurement Value
Outer piece 19.67 mm
Inner hole 20.14 mm

Kerf Calculation

Kerf is calculated using:

Kerf = (Inner − Outer) ÷ 2

Kerf = (20.14 − 19.67) ÷ 2

Kerf = 0.47 ÷ 2

Kerf = 0.235 mm

Therefore the laser kerf = 0.235 mm Kerf outer piece alt text

Kerf inner hole alt text

Slot Tolerance Testing

To determine the best press-fit slot width, we produced 11 slot variations using the Kerf Check Tool by Doyo-sensei.

Tool used: http://doyolab.net/appli/kerf_check/kerf_check.html

Test Parameters

  • Starting slot width: 2.5 mm
  • Increment: 0.05 mm
  • Total slots: 11

Tolerance test alt text

Laser Cutting Test

All tolerance slots were cut using identical machine parameters.

Material: MDF Thickness: 2.99 mm

Parameter Value
Power 30 %
Speed 50 mm/s
Passes 1
Focus 6 mm

Tolerance slots cut alt text

Press-Fit Testing

Each slot was tested by inserting a laser cut MDF tab.

Component Measurement
Tab width 2.98 mm
Best slot width 2.805 mm

Observations

  • Slots below 2.70 mm → too tight
  • Slots above 2.90 mm → too loose
  • 2.805 mm produced the best friction fit

Slot testing alt text

Challenges and Debugging

During testing we discovered that the laser cutter was not cutting correctly.

Even at 100% power and very slow speed, the machine failed to cut MDF.

No cut at maximum power

After inspection we discovered that the focusing lens was damaged.

Damaged lens

Repair Process

  1. Removed the damaged lens
  2. Purchased a replacement lens
  3. Installed new 18 mm / 63.5 mm focal length lens
  4. Cleaned the mirrors and optics

New lens installed

Lens mounted

After the repair the machine successfully cut MDF using normal parameters.

Successful cut

The troubleshooting process took two days, but successfully restored the machine to working condition.

What the Machine Can and Cannot Do

The GS Laser System performs well for:

  • MDF
  • Plywood
  • Acrylic
  • Cardboard

However it cannot cut metal because it is a CO₂ laser system.

Personal Reflection

Participating in the laser cutter characterization helped us understand how small parameter adjustments can greatly affect cutting quality and dimensional accuracy.

Understanding kerf, focus, and cutting parameters is essential when designing press-fit assemblies or other precision laser-cut components.

These results were used directly in our individual assignments to design parametric press-fit kits.

Reference

What Is Laser Cutting Kerf? https://www.xtool.com/blogs/xtool-academy/laser-cutting-kerf