For Thing-A-Day Day 01 I created a pegboard suitable for mounting and testing gear trains and similar, using Tony Buser's fabulous Pin Connector V2 tools as a first experiment. I figured this tool might be useful for the MakerBot Clock Makers project and for educators and students looking to explore basic gear mechanics. This tool will become more useful as people (maybe you? maybe me?) generate tools to lock gears into place for heavier use.
Lasercut using plywood or acrylic. (I'll be using 6mm birch plywood.) The fixed bolt-holes (8mm) are for mounting heavy-use elements such as a crank to start the train moving or the element your train is driving.
You can also use 8mm metric hardware to mount gears -- benefit being the use of nuts to pin elements firmly in place for more complicated/torque-requiring activities.
I will print some pin connectors and share the STLs here along with recommendations for settings for Tony's OpenSCAD tool.