Overhang Challenge
A single-spiral calibration piece for testing how aggressive your printer can go on overhangs. The toolpath starts with a solid spiral base for a strong foothold, rises as a narrow vertical cylinder, then spirals outward at a configurable overhang angle. Print it, measure where the spiral starts to fail, and use the result to tune your overhang strategy for real prints.
See Predefined Models for the general workflow and how to select this model.
Parameters (sliders)
Parameters
Base Diameter- Diameter of the bottom spiral base in mm (15–60). Larger bases give more bed-adhesion and a sturdier foot.
Cylinder Diameter- Diameter of the straight-up section in mm (2–20). The overhang spiral grows outward from this cylinder.
Spiral Lines Overlap- Overlap between adjacent spiral lines (0–50 %). 15–20 % is a good default for the base spiral.
Cylinder Height- Height of the straight-up section in mm (5–40). Higher cylinders let you test long overhangs without stretching the whole challenge tall.
Overhang Angle- Angle of the outward-spiraling overhang in degrees (0–90). 0 means pure cantilever (impossible); 45 is a typical FDM limit; 90 means vertical (no overhang).
Overhang Layer Height- Layer height used in the overhang section in mm (0.1–0.5). Thinner layers (0.1–0.15) help droopy overhangs stay aligned.
Overhang Width- How far the overhang spiral extends radially from the cylinder (mm, 5–50). Controls the total diameter of the finished piece.
How it works
- Base spiral: a flat outward spiral from the centre to Base Diameter gives bed adhesion.
- Cylinder: a narrow vertical cylinder at Cylinder Diameter rises to Cylinder Height.
- Overhang spiral: from the top of the cylinder, the toolpath spirals outward and downward. The radial step per revolution is tied to Overhang Angle (
tan(angle)of the slope) and the Z step is set by Overhang Layer Height. - The entire toolpath is a single continuous polyline — there are no travel moves or retractions.