Week 3: Computer Controlled Cutting¶

Group Assignment Requirements¶

Do lab’s safety training
Characterize your laser cutter’s:
Focus
Power
Speed
Rate
Kerf
Joint clearance
Types
Documentation
Document work on the group work page
Reflect on individual page about what you learned

During this week we started by learning about the machines in CPF Makerspace, primarly focusing on the laser cutting machine, and the vinyl cutter:

Machine Specifications¶

Specification	Trotec Speedy 400	Roland GS-24
Machine Type	CO₂ Laser Cutter	Vinyl Cutter
Function	Cutting & engraving a wide range of materials (wood, acrylic, leather, etc.)	Cutting vinyl and thin materials for decals, signage, stencils
Max Power	Up to 120W CO₂	Blade force 30–350 gf
Work Area	1016 mm × 610 mm	Max cutting width 584 mm
Max Speed	Up to 4.3 m/s	Up to 500 mm/s
Software Used	Trotec JobControl	Inkscape / Roland CutStudio
Datasheet	https://www.troteclaser.com/en/laser-machines/laser-engraver/speedy-400-fastest-laser-engraver-cutter	https://www.rolanddg.eu/products/vinyl-cutters/camm-1-gs-24-desktop-vinyl-cutter

Our Instructor Naim Haj-Ali explained the key concepts of operating the laser cutter and walked us through the tests we performed using 2–3 mm MDF wood.

Important Definitions (Laser Cutting)¶

Focal Point: The precise distance between the laser lens and the material where the laser beam is most concentrated, producing the smallest and most powerful spot.
Laser Power: The amount of energy emitted by the laser (measured in watts). Higher power increases cutting ability but may cause more burning.
Speed: The movement rate of the laser head across the material (mm/s). Higher speed reduces exposure time; lower speed increases material burn.
Kerf: The width of material removed by the laser beam during cutting.
Joint Clearance: The intentional gap designed between two interlocking parts to ensure proper fit after accounting for kerf.

Laser Cutting Tests (Material: MDF 2–3 mm)¶

1) Focal Point Test¶

Determines the optimal focus distance.
Ensures clean cuts and minimal charring.

2) Power vs Speed Test¶

Tests different power and speed combinations.
Identifies settings that fully cut the material without excessive burn marks.

3) Kerf Test¶

Measures the material removed by the laser.
Used to calculate accurate press-fit tolerances.

Focal Point Test Workflow and Results¶

Software Used: Inkscape + AutoCAD (DXF)

Power VS Speed Workflow and Results¶

The goal of this test was to find the optimum power to speed ratio of cutting MDF 2.3mm (our material)

1) We started by creating a template design containg 14-16 Circles and engraved text definers such as (Material,Speed,Power)

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2) Import the DXF file into inkscape to define color set strokes , ensure Hairline settings are applied and input different power vs speed values

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3) Open JC Control and ensure that the cutting settings are well defined (We created a custom setting file)

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Results¶

1) It was found the ideal power to speed ratio on MDF 2.3 mm was (Power = 60 to 70, Speed = 0.3-0.4) 2) This result is based on the optimum Focal Point found in Focal Point Test (z=0)

Kerf Test¶

The goal of this test was to find and calculate the Kerf Value

1) We started by creating a template design containg slots inceasing in gap size by 0.05 mm and engraved text definers such as (Material,Actual Readings vs CAD dimensions)

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2) Import the DXF file into inkscape to define color set strokes , ensure Hairline settings are applied and input different power vs speed values

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3) Manually measure the cut pcs using digital callipers and compare them with the cut slots

4) Use a piece of the same material to define the perfect joint

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