LEGO launcher in OpenSCAD

thingiverse

This text demonstrates the creation of a LEGO catapult using a lever and fulcrum inspired by the "Made by Joel" website (http://madebyjoel.com/2012/05/small-catapult-toy.html). It also provides an opportunity to experiment with laser-cut parts in OpenSCAD and test laser-cutter offsets for peg-joint press-fit accuracy. The initial laser-cut attempt wasn't successful due to a too-loose fit resulting from perfect tolerance in OpenSCAD. To resolve this, the author added xy-plane thickness to the pegs using minkowski() to make them thicker. A 0.375mm offset was found to provide a perfect press-fit without requiring glue or hammering, while a 0.5mm offset was too tight and required hammering, which stripped laminate layers. The idea and initial offset dimensions were sourced from Thingiverse (thing:27736). Research suggests that the laser cuts a v-shaped notch, with width and depth influenced by power and speed settings. The optimal offset worked with 4.75mm baltic birch plywood, Epilog 36-EXT laser at SPEED=08, POWER=85, and FREQ=450. The OpenSCAD code includes numerous comments and test modules.