3DPrintCalcs
Clearance Calculator — Gap for Moving Parts
Calculate the gap needed between moving or sliding 3D printed parts.
How We Calculate This
Clearance Formulas
- Min gap = max(Nozzle diameter x Motion multiplier + Material adjustment, printable floor)
- Printable floor = max(Nozzle diameter, 2 x Layer height)
- Recommended gap = Min gap + Size tolerance + 0.1mm safety
- Size tolerance = Part size x 0.2%
- Design gap = Recommended gap rounded up to 0.05mm
The motion multiplier adjusts for different joint types: sliding needs full clearance, rotating needs slightly less, and print-in-place needs extra to account for printing artifacts.
The minimum gap is clamped to a printable floor. A horizontal (XY) gap cannot be thinner than one extrusion width — AON3D's tightest recommended sliding fit is 1x extrusion width (about one nozzle diameter), because the slicer cannot trace a thinner gap. A vertical (Z) gap is held to at least twice the layer height, a common starting point for print-in-place sliding clearances. The motion multipliers and material adjustments are tool-specific design heuristics — always confirm with a clearance test print for your printer and material.
Frequently Asked Questions
The absolute minimum is one nozzle width (typically 0.4mm), as the slicer cannot create a gap smaller than it can trace around. For reliable motion, use 0.4-0.6mm for sliding parts and 0.3-0.5mm for rotating joints.
Print-in-place mechanisms are printed as one piece with built-in clearances. They need 50% more gap than post-assembly parts because slight oozing and elephant foot can partially fill the gaps during printing.
Yes. Gaps aligned with the Z axis (vertical) are more accurate because they depend on layer positioning. Horizontal gaps depend on XY positioning which has different accuracy characteristics.
Print a clearance test model with gaps from 0.1mm to 1.0mm in 0.05mm steps. Check which gaps allow free movement. This tells you your specific printer minimum clearance and should be done for each material.
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Support Calculator
Estimate extra material and time needed for support structures.
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Last updated: February 2026
All calculations are estimates. Always verify settings with test prints before committing to final prints.