Tolerances

Dimensional Accuracy and Tolerances

Typical accuracy for FDM printers is around ±0.1 mm, but for our Ultimaker machines ±0.15 ～ 0.2 mm is more realistic.

For mating parts to print on our machine, leave 0.15–0.2 mm clearance to ensure proper fit.

Hole = the opening or cavity
Pin = the protruding post designed to fit into the hole
Example: Pin = 10.00 mm, Hole = 10.20 mm → gives 0.20 mm clearance for smooth assembly.

Design the Holes in Fusion

Take M2 as an example:
For M2 screws (nominal diameter 2.0 mm) in 3D-printed parts, the hole size can be adjusted depending on how tight you want the fit and how fragile the part is.

Base diameter: 2.0 mm
Recommended tolerance range: +0.2 mm ~ –0.1 mm

Through Hole Design Guideline：

Option 1: +0.2 mm (≈ 2.2 mm) (frequently used) → Just fit: the screw slides in easily, ideal for normal assemblies.

Option 2: 0 mm (2.0 mm) → Snug fit: requires slight twisting or pushing to insert; provides mild positional accuracy.

Option 3: –0.1 mm (≈ 1.9 mm) → Tight fit: may need to be drilled or forced in; creates a very secure hold but not recommended for thin or brittle parts (e.g. PLA) as it may cause cracking.

Tapping Hole Design Guide

Option 1: A tapped 3mm hole works for M2 screws.

Option 2: 3mm Hole + thread