Summary

This is a working combination padlock design that can be used in place of a standard Master Lock on a locker or whatever. It's relatively strong, but it is plastic, so it's not for high security. This is not mine. This is by BCaron on Thingiverse.

UPDATE 8/22/2024:

Fixed the body models adding more clearance around the detents and springs. Use Body_FIXED.STL. This should resolve the printing issues many people are having.

Added an option to print the springs separately if you prefer. The springs work quite well this way and should be easier to print successfully. Use Body_noSprings.STL and Spring.STL. Updated instructions are below.

Features:

Configurable combination: up to 10,000 possible combinations

Selectable security options: 3 or 4 tumblers with 6 or 10 digit numbers

Spring loaded detent feature on tumblers for precise positioning and satisfyingly tactile feedback

Similar dimensions to classic rotary Master Lock for compatibility with most lockers and other latches

Strong lock body and shackle that resists forcing open

Normal or long shackle options for securing larger latches

SolidWorks files for your own customization

v2 Improvements:

Print-in-place springs for detent works far better than old design which would break after a while

Option for 3 or 4 tumbler lock and 6 or 10 digit tumblers

Threaded cap eliminates glue and allows for easier changing of combination.

Taller wall next to shackle latch better resists forcing open of the lock

Flipped tumbler position for easier right-handed operation

Tumblers can now be printed without supports

Various changes to make printing easier and cleaner

Combination Padlock

0.2mm layer, 2 walls, 15% infill