Overscan

Overscan extends raster engraving lines beyond the actual content area to ensure the laser reaches constant velocity during engraving, eliminating acceleration artifacts.

The Problem: Acceleration Marks

Without overscan, raster engraving suffers from acceleration artifacts:

• Light edges where acceleration starts (laser moving too fast for power level)
• Dark edges where deceleration occurs (laser dwelling longer)
• Inconsistent engraving depth/darkness across each line
• Visible banding or streaking at line edges

How Overscan Works

Overscan extends the toolpath before and after each raster line:

Process:

1. Lead-in: Laser moves to a position before the line starts
2. Accelerate: Laser accelerates to target speed (laser OFF)
3. Engrave: Laser turns on and engraves at constant speed
4. Decelerate: Laser turns off and decelerates after the line ends

Result: The entire engraved area receives consistent power at constant velocity.

Benefits:

• Even engraving depth across entire raster line
• No light/dark edges
• Higher quality photo engraving
• Professional-looking results

Configuring Overscan

Overscan is a transformer in the Rayforge workflow pipeline.

To enable:

1. Select the layer with raster engraving
2. Open workflow settings (or operation settings)
3. Add Overscan transformer if not already present
4. Configure distance

Settings:

Setting	Description	Typical Value
Enabled	Toggle overscan on/off	ON (for raster)
Distance (mm)	How far to extend lines	2-5 mm

Choosing Overscan Distance

The overscan distance should allow the machine to fully accelerate to target speed.

Practical guidelines:

Max Speed	Acceleration	Recommended Overscan
3000 mm/min (50 mm/s)	Low	5 mm
3000 mm/min (50 mm/s)	Medium	3 mm
3000 mm/min (50 mm/s)	High	2 mm
6000 mm/min (100 mm/s)	Low	10 mm
6000 mm/min (100 mm/s)	Medium	6 mm
6000 mm/min (100 mm/s)	High	4 mm

Factors affecting required distance:

• Speed: Higher speed = need more distance to accelerate
• Acceleration: Lower acceleration = need more distance
• Machine mechanics: Belt-driven vs direct-drive affects acceleration

Tuning:

• Too little: Acceleration marks still visible at edges
• Too much: Wastes time, may hit machine boundaries
• Start with 3mm and adjust based on results

Testing Overscan Settings

Test procedure:

1. Create a test engraving:

   • Solid filled rectangle (50mm x 20mm)
   • Use your typical engraving settings
   • Enable overscan at 3mm

2. Engrave the test:

   • Run the job
   • Allow to complete

3. Examine the edges:

   • Look at left and right edges of the rectangle
   • Check for darkness variation at edges
   • Compare edge darkness to center darkness

4. Adjust:

   • If edges are lighter/darker: Increase overscan
   • If edges match center: Overscan is sufficient
   • If edges are perfect: Try reducing overscan slightly to save time

When to Use Overscan

Always use for:

• Photo engraving (raster)
• Fill patterns
• Any high-detail raster work
• Grayscale image engraving
• Text engraving (raster mode)

Optional for:

• Vector cutting (not needed)
• Very slow engraving (acceleration less noticeable)
• Large simple shapes (edges less critical)

Disable for:

• Vector operations
• Very small work areas (may exceed boundaries)
• When edge quality is not important

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Related Topics

• Engraving Operations - Configure engraving settings
• Material Test Grid - Find optimal power/speed