3D Printable Screw Generator for Fusion 360 (Optimized Threads)

Iker Libano | KNIN Custom

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Description

3D Printable Screw Generator for Fusion 360

This is a fully editable Fusion 360 file designed to generate screws specifically optimized for 3D printing.

Most standard metric threads are designed for metal manufacturing, not for FDM printing.
That means they usually have:

overly sharp thread profiles
unsupported overhangs
tiny fragile tips
unreliable tolerances

This generator solves those problems by allowing you to fully customize the geometry of the thread depending on:

your printer
your material
your layer height
your nozzle size

The goal is simple:
Create screws that print reliably and work consistently.

Features

Fully parametric Fusion 360 file
Adjustable thread angle
Adjustable minimum thread section
Adjustable tolerances
Automatic nut generation
Horizontal split screw version for extra strength
Auto-updating labels and dimensions
Optimized specifically for FDM printing
Works great with PLA and PETG

YouTube video

Full explanation and engineering breakdown here:

The video explains:

how printable threads work
why standard threads fail
how to optimize screws for FDM printing
how to use this generator
how to create stronger printable screws

Important: How printable threads work

A standard metric thread is usually NOT ideal for 3D printing.

There are 2 major problems:

1. Overhang angle

Very sharp thread angles create unsupported geometry.
Your printer ends up printing partially in the air, which causes sagging and poor precision.

This generator allows you to adjust the thread angle so the screw prints cleanly without supports.

Recommended values:

35° → better mechanical performance
45° → maximum reliability

2. Tiny sharp thread tips

Standard threads end in extremely small sharp points.

FDM printers have a physical limit regarding the smallest detail they can print reliably.
If the tip is too thin, the thread becomes inconsistent and fragile.

The parameter SECTION_MIN controls the minimum flat section at the tip of the thread.

Recommended values:

0.3 mm minimum
Higher values = easier printing and stronger threads
Lower values = more compact threads and better mechanical advantage

User parameters

Only the parameters marked with a blue star should be modified.

`LARGO`

Length of the threaded section.

`DIAMETRO_EXT`

Outer diameter of the screw.

`SECTION_MIN`

Minimum flat section at the tip of the thread.

`ANGULO`

Angle of the thread walls.

`TOLERANCIA`

Clearance between screw and nut.

Recommended:
0.15 mm

`TUERCA`

Nut size multiplier.

1 = standard nut
2 = double-size nut
etc.

Vertical vs Horizontal Screws

This project includes two versions:

Horizontal split screw (default)

The screw is split in half and designed to be printed horizontally.

This makes the screw significantly stronger because the layer orientation follows the forces applied to the thread.

A centering skeleton is included to align both halves.

Standard vertical screw

If you want the normal vertical version:

Simply go one step back in the Fusion 360 timeline.

The final split operation will disappear and you will get the standard screw version.

Internal hole

The screw includes a central hole.

This may seem counterintuitive, but it actually increases strength on vertically printed screws because it generates additional perimeter walls inside the part.

Most of the strength in FDM prints comes from walls/perimeters, not infill.

Reference cube

The small cube marked with "XZ" is a 20x20 mm calibration cube used only as a scale reference.

This helps visualize the actual size of the screw while designing.

Notes