LEGO Gear Designer

Setup

• Print the gear flat, gear axis straight up (Z). Counterbores and axle holes need no supports.
• Starting points: 0.4 mm nozzle, layers 0.12–0.2 mm, PETG or PLA.
• 3+ perimeters (≥1.2 mm walls); infill 40 %+, 100 % for small gears.
• Outer wall 30–40 mm/s; first layer 0.1–0.2 mm to counter elephant-foot.

Test first

• Print an 8T + 24T pair before the real one.
• Check axle spin, pin fit in the counterbore, and smooth meshing.
• Fit off? Tune in order: bore clearance → backlash → counterbore diameter.

Notes