Hinge Calculator — Print-in-Place Hinge Dimensions

Hinge Dimension Formulas

• Hole diameter = Pin diameter + 2 x Clearance
• Min wall = Nozzle diameter x Wall multiplier (default 3)
• Outer diameter = Hole diameter + 2 x Min wall
• Gaps between knuckles = Knuckle count − 1
• Knuckle length = (Hinge width − Gaps x Clearance) / Knuckle count
• Knuckle pitch = Knuckle length + Clearance (centre-to-centre slot spacing along the pin)

The clearance gap around the pin allows rotation. The knuckles alternate between the two hinge halves. At least 3 knuckles are needed (2+1) for the hinge to function properly.

This calculator assumes a flat-printed hinge, so the same clearance value sets both the radial gap around the pin and the axial gap between adjacent knuckles — both lie in the XY plane where 0.2-0.3 mm is the sweet spot for a 0.4 mm nozzle. If you print the barrel standing up (knuckles stacked in Z), set the axial gap to at least two layer heights instead, as Z-direction fusing behaves differently.