Layer by Layer: How 3D Printing Works

Every 3D print is built up from thin horizontal layers

1

The Slicing Moment

Before printing, software "slices" your 3D model into thin horizontal layers. Each layer is a 2D cross-section at that height. Drag the slider to slice through.

3D Model (Side View)

Layer Cross-Section (Top View)

50 / 100
0.2mm

Why Layer Height Matters

0.1mm layers = 200 layers per 20mm = smooth but slow
0.3mm layers = 67 layers per 20mm = fast but visible lines

The Math of Slicing

A sphere at height h has radius r = √(R² - h²)
That's why middle layers are biggest!

2

Inside a Layer

Each layer isn't just a flat shape. Toggle the components to see how a layer is built up.

3 walls
20%
Why Multiple Walls?

More walls = stronger outer shell. 2-3 walls is typical. Functional parts might use 4-5.

3

The Print Path

Watch the nozzle trace out a single layer in real-time. Walls first, then infill.

0%
Progress
Waiting
Current Phase
0mm
Extruded

Perimeters First

Clean edges require tracing the outline before filling. This prevents infill from showing through.

Travel Moves

Dotted lines = nozzle moving without extruding. Good slicers minimize these to prevent stringing.

4

Infill Patterns

The pattern inside your print affects strength, weight, and time. Click to compare, then adjust density.

20%
~18g
Material
Medium
Strength
~2.1h
Print Time
All
Strong Direction
Pro Tip

Gyroid and Honeycomb are favorites because they're equally strong in all directions. Lines/Rectilinear are faster but only strong along the line direction.

5

Orientation Matters

Drag to rotate the model and watch how it affects layers, time, and support needs.

← Drag to rotate →
100
Layers
2.5h
Est. Time
None
Supports
Strong
Layer Strength

The 45° Rule

Overhangs steeper than 45° from vertical usually need supports. Each layer can only extend so far over the previous one.

Layer Lines = Weak Points

Parts are weakest perpendicular to layers. Orient so stress doesn't try to pull layers apart.

Flat = Faster

Fewer layers means faster prints. But sometimes you need height for strength or detail.

Layer Master!

You've discovered how 3D printers turn digital models into physical objects - one layer at a time. Now go create something!

0
Layers Explored
0
Patterns Tried
0
Time Exploring

Slicing is Key

Software divides 3D models into horizontal layers - the shape at each height becomes a 2D path.

Layer Height = Quality vs Speed

0.1mm layers are smooth but slow. 0.3mm is fast but shows visible lines.

Infill Saves Material

Objects aren't solid - patterns like honeycomb provide strength with 80% less plastic.

Walls Then Fill

The printer traces outlines (perimeters) first, then fills the inside.

Orientation = Everything

Rotating a model changes layer count, print time, strength, and support needs.

Overhangs Need Support

Angles beyond 45° from vertical need temporary support structures.

Ready to Create?

Put your new knowledge into practice!

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