Tutorial 9: Overhang Angle Coloring and Print Safety

A beautiful profile is only useful if it can actually be printed. The G-code Sculptor displays real-time overhang angle coloring on the profile curve — in both the side-panel canvas and the in-viewport overlay — giving you instant visual feedback about which parts of your design are safe, risky, or dangerous to print. In this tutorial you will learn how to read this coloring and use it to create reliably printable designs.

What you'll learn

What overhang angle means in the context of FDM printing
How the three color zones (theme accent / yellow / red) work
How to read the profile curve coloring in real time, in both editors
How to fix problematic overhang areas
Design techniques for staying within safe angles
How Total Height affects overhang calculations

Prerequisites

A profile with at least 3 points (a shape with some curvature).
Understanding of handles and curve shaping (Tutorials 1–4).

Step 1: What is overhang angle?

Overhang angle measures how far the wall deviates from vertical. It is calculated from the tangent of the profile curve at each point:

0° — the wall is perfectly vertical (a cylinder). Every layer sits directly on top of the previous one. This is the safest condition.
45° — the wall is leaning outward at a 45-degree angle. Each layer overhangs the one below by about one layer's height. Most printers handle this with cooling.
90° — the wall is completely horizontal. There is no support below — the filament hangs in mid-air. This will almost certainly fail.

Step 2: Identify the three color zones

The profile editor colors the curve in three zones based on the overhang angle at each segment:

Color	Angle Range	Meaning
Theme Accent Primary	0° – 45°	Safe. The wall is within normal printing capability.
Yellow / amber	45° – 60°	Warning. Printing is possible but may show surface artifacts, drooping, or rough texture.
Red	Above 60°	Danger. The overhang is steep enough that printing will likely fail without support structures.

The safe-zone color is your theme's Accent Primary — the same color used by the spline anchors and handles. Line and dots always read as one consistent element. If you swap themes, the safe color follows along automatically.

Step 1

Look at the curve colors

Examine your profile curve — both on the side-panel canvas and on the in-viewport overlay. Vertical sections should be in the accent color. Areas where the curve flares outward (radius increasing rapidly with little height change) should trend toward yellow / amber or red.

Step 3: Create a design with problem areas

Step 2

Force red/yellow regions

Create a profile with an extreme flare:
1. Bottom point at radius 15 mm
2. Middle point (50% height) at radius 15 mm
3. Top point at radius 40 mm

The top section — where the radius jumps from 15 to 40 mm — should display yellow or red coloring because the wall is leaning outward steeply.

Step 4: Fix overhang issues by adjusting the curve

There are several strategies for fixing problematic overhangs:

Strategy A: Spread the change over more height

Step 3

Gradual transition

Instead of jumping from 15 mm to 40 mm in the top half, start the flare earlier:
1. Move the middle point downward (to 30% height)
2. The radius change now spans 70% of the total height instead of 50%
3. Watch the coloring shift from red/yellow back toward the safe accent color as the transition becomes more gradual

Strategy B: Increase the Total Height

Step 4

Make the object taller

Increase the Total Height from 50 mm to 100 mm. The same radius change now happens over a taller object, so each layer's overhang is reduced. The curve coloring should improve.

Strategy C: Add intermediate points

Step 5

Add a stepping stone

Add an intermediate point between the narrow and wide sections. Set its radius to a value between the two extremes (say 25 mm). Use Smooth handles to create a gradual S-curve transition. The coloring should soften to yellow or back into the safe accent color.

Strategy D: Use Sharp mode for controlled steps

Step 6

Step instead of slope

Instead of a gradual curve, create a sharp horizontal step where the radius changes. Set the mode to Sharp. While the step itself has an extreme angle, the vertical walls above and below it stay in the safe accent color. This can work if the step is small (1–2 mm of radius change).

Step 5: Understand how handles affect overhang

Step 7

Experiment with handle angles

Select a Smooth point and drag its handle to point more horizontally. The curve becomes flatter near that point, increasing the overhang angle. Now drag it more vertically — the curve becomes steeper, reducing the overhang.

Handles that point horizontally create broad, gentle curves but can push the overhang into the yellow/red zone. Handles that point more vertically create tighter transitions that stay in the safe accent zone.

Step 6: Read the angle legend

Step 8

Check the legend

The profile canvas may include a small angle legend showing the color bands. If available, hover over different parts of the curve to see the exact angle value at that point. This gives you precise feedback for fine-tuning.

Step 7: Material-specific considerations

Different materials tolerate different overhang angles:

Material	Safe Angle	Notes
PLA	Up to 50–55°	Good bridging, cools quickly
PETG	Up to 40–45°	Stringy, droops more
ABS	Up to 40–45°	Needs enclosure, curls
TPU	Up to 35°	Flexible, droops significantly

Outcome

You can now read and act on overhang angle coloring:
- Theme accent color = safe, print with confidence
- Yellow / amber = caution, may need slower speeds or better cooling
- Red = redesign needed or accept visible artifacts
- Fix overhangs by gradual transitions, taller objects, more control points, or different handle angles

What's Next

Tutorial 10: Complete Vase Design Workflow — Bring everything together in a complete start-to-finish workflow: profile shaping, effect stacking, print settings, and export.