Summary

Another one of the playthings that our parents have in their toybox is a set of joiners for iceblock sticks.

Instructions

Print the model files
Attach iceblock sticks to make large constructions
Remove sticks and place again to make different constructions

The original pieces had fairly flexible plastic, so tolerances may need to be adjusted for PLA (or ABS) to work in this case.

OpenSCAD file is included with most things parametrised. I used convex hulls of double-radius cylinders to generate 45° overhangs, which worked wonderfully.

Iceblock Stick Joiners