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Contour Cutting

Contour cutting traces the outline of vector shapes to cut them free from material. It's the most common laser operation for creating parts, signs, and decorative pieces.

Overview​

Contour operations:

  • Follow vector paths (lines, curves, shapes)
  • Cut along the perimeter of objects
  • Support single or multiple passes for thick materials
  • Can use inside, outside, or on-line cutting paths
  • Work with any closed or open vector shape

When to Use Contour​

Use contour cutting for:

  • Cutting parts free from stock material
  • Creating outlines and borders
  • Cutting shapes from wood, acrylic, cardboard
  • Perforating or scoring (with reduced power)
  • Creating stencils and templates

Don't use contour for:

  • Filling areas (use Engrave instead)
  • Bitmap images (convert to vectors first)

Creating a Contour Operation​

Step 1: Select Objects​

  1. Import or draw vector shapes on the canvas
  2. Select the objects you want to cut
  3. Ensure shapes are closed paths for complete cuts

Step 2: Add Contour Operation​

  • Menu: Operations Add Contour
  • Shortcut: ctrl+shift+c
  • Right-click: Context menu Add Operation Contour

Step 3: Configure Settings​

Contour step settings

Key Settings​

Power & Speed​

Power (%):

  • Laser intensity from 0-100%
  • Higher power for thicker materials
  • Lower power for scoring or marking

Speed (mm/min):

  • How fast the laser moves
  • Slower = more energy = deeper cut
  • Faster = less energy = lighter cut

Multi-Pass Cutting​

For materials thicker than a single pass can cut:

Passes:

  • Number of times to repeat the cut
  • Each pass cuts deeper

Pass Depth (Z-step):

  • How much to lower Z-axis per pass (if supported)
  • Requires Z-axis control on your machine
  • Creates true 2.5D cutting
  • Set to 0 for same-depth multiple passes
Z-Axis Required

Pass depth only works if your machine has Z-axis control. For machines without Z-axis, use multiple passes at the same depth.

Path Offset​

Controls where the laser cuts relative to the vector path:

OffsetDescriptionUse For
On LineCuts directly on the pathCenterline cuts, scoring
InsideCuts inside the shapeParts that must fit exact size
OutsideCuts outside the shapeHoles that parts fit into

Offset Distance:

  • How far inside/outside to offset (mm)
  • Typically set to half your kerf width
  • Kerf = width of material removed by laser
  • Example: 0.15mm offset for 0.3mm kerf

Cut Direction​

Clockwise vs Counter-Clockwise:

  • Affects which side of the cut gets more heat
  • Usually clockwise for right-hand rule
  • Change if one side burns more than the other

Optimize Order:

  • Automatically sorts paths for minimum travel
  • Reduces job time
  • Prevents missed cuts

Advanced Features​

Contour post-processing settings

Holding Tabs​

Tabs keep cut pieces attached to stock material during cutting:

  • Add tabs to prevent pieces from falling
  • Tabs are small uncut sections
  • Break tabs after job completes
  • See Holding Tabs for details

Kerf Compensation​

Kerf is the width of material removed by the laser beam:

Why it matters:

  • A circle cut "on line" will be slightly smaller than designed
  • The laser removes ~0.2-0.4mm of material (depending on beam width)

How to compensate:

  1. Measure your kerf on test cuts
  2. Use path offset = kerf/2
  3. For parts: offset inside by kerf/2
  4. For holes: offset outside by kerf/2

See Kerf for detailed guide.

Lead-In/Lead-Out​

Lead-ins and lead-outs control where cuts start and end:

Lead-in:

  • Gradual entry to the cut
  • Prevents burn marks at start point
  • Moves laser to full speed before hitting the material edge

Lead-out:

  • Gradual exit from the cut
  • Prevents damage at end point
  • Common for metals and acrylics

Configuration:

  • Length: How far the lead extends (mm)
  • Angle: Direction of the lead path
  • Type: Straight line, arc, or spiral

Tips & Best Practices​

Material Testing​

Always test first:

  1. Cut small test shapes on scrap
  2. Start with conservative settings (lower power, slower speed)
  3. Gradually increase power or decrease speed
  4. Record successful settings

Cutting Order​

Best practices:

  • Engrave before cutting (keeps material secured)
  • Cut inside features before outside perimeter
  • Use holding tabs for parts that might move
  • Cut smallest parts first (less vibration)

Troubleshooting​

Cuts not going through material​

  • Increase: Power setting
  • Decrease: Speed setting
  • Add: More passes
  • Check: Focus is correct
  • Check: Beam is clean (dirty lens)

Excessive charring or burning​

  • Decrease: Power setting
  • Increase: Speed setting
  • Use: Air assist
  • Try: Multiple faster passes instead of one slow
  • Check: Material is appropriate for laser cutting

Parts fall out during cutting​

  • Add: Holding tabs
  • Use: Cutting order optimization
  • Cut: Inside features before outside
  • Ensure: Material is flat and secured

Inconsistent cut depth​

  • Check: Material thickness is uniform
  • Check: Material is flat (not warped)
  • Check: Focus distance is consistent
  • Verify: Laser power is stable

Missed corners or curves​

  • Decrease: Speed (especially on corners)
  • Check: Machine acceleration settings
  • Verify: Belts are tight
  • Reduce: Path complexity (simplify curves)

Technical Details​

Coordinate System​

Contour operations work in:

  • Units: Millimeters (mm)
  • Origin: Depends on machine and job setup
  • Coordinates: X/Y plane (Z for multi-pass depth)

Path Generation​

Rayforge converts vector shapes to G-code:

  1. Offset path (if inside/outside cutting)
  2. Optimize path order (minimize travel)
  3. Insert lead-in/lead-out (if configured)
  4. Add holding tabs (if configured)
  5. Generate G-code commands

G-code Commands​

Typical contour G-code:

G0 X10 Y10          ; Rapid move to start
M3 S204             ; Laser on at 80% power
G1 X50 Y10 F500     ; Cut to point at 500 mm/min
G1 X50 Y50 F500     ; Cut to next point
G1 X10 Y50 F500     ; Continue cutting
G1 X10 Y10 F500     ; Complete the square
M5                  ; Laser off