Ice Lock

thingiverse

Ice-based timed lock. Freeze the pin in the body, and at room temperature, it will take 2-3 hours for the ice to melt enough to release the pin. It's a nice alternative to cobbling together an electromechanical timed lock, and more reliable as long as you're not in a freezer :P Printed in Hatchbox PETG at 246C, the lock will support >100lbf with fresh ice inside. PLA also works well, but ABS prints have shattered from the expanding ice. If your print isn't watertight, try increasing the extrusion multiplier by ~15%. The intent is to print with the following settings: 0.5mm extrusion width, 2 wall outlines, 0.3mm layer height, I used 20% infill.