What clearance do print-in-place hinges need?

Typically 0.25-0.4mm clearance around the pin, depending on your printer. Too tight and the hinge will not move; too loose and it will be wobbly. Start with 0.3mm and adjust based on test prints.

How many knuckles should a hinge have?

Three knuckles (2 on one side, 1 on the other) is the minimum for a working hinge. Five knuckles gives a stronger, smoother hinge. More knuckles = stronger but harder to print cleanly.

Do print-in-place hinges need to be broken free?

Yes, most print-in-place hinges need to be gently flexed to break the slight bonds between the pin and knuckle. Work them back and forth carefully. If they are stuck solid, the clearance was too small.

What pin diameter works best?

For FDM printing, pins of 3-6mm diameter work well. Below 3mm, the pin becomes fragile. Above 6mm, the clearance gaps become large relative to print features. The pin should be at least 6x the nozzle diameter.

3DPrintCalcs

Hinge Calculator — Print-in-Place Hinge Dimensions

Design print-in-place hinges with correct clearance and pin dimensions.

Pin Diameter

Clearance

Gap around pin

Hinge Width

Knuckle Count

Use odd numbers

Nozzle Diameter

How We Calculate This

Hinge Dimension Formulas

Hole diameter = Pin diameter + 2 x Clearance
Min wall = Nozzle diameter x 3
Outer diameter = Hole diameter + 2 x Min wall
Knuckle length = (Total width - Gaps) / Knuckle count

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.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify settings with test prints before committing to final prints.