Laser Cut Finger Joints

One of the most versatile machines in a college makerspace is the Laser Cutter.

It enables you to build things larger than a 3D print build plate 10x faster than you could any other way. The secret is to weave 2D cut geometries into 3D parts. The best way (or at least a very popular way) to do this is by fingering your joints to increase gluing surface area (the wood is usually too thin to screw together without splitting it).

Most makerspace helpers will point you to a fingered box site like this. But what if you don’t want to make a simple box? What if you have higher aspirations? For your sake, we hope you do.

Welp, in Solidworks your main option involves drawing an absurd number of lines and offsetting them. Odds are, you mess something up and you have to do it all over again. Though it is a rite of passage to experience this pain at least once, it’s also an enormous waste of materials, money, and time. Trust us when we say there are 101 better ways you can and will waste your time when it comes to projects.

Born from the depths of this struggle is one of our favorite Onshape features: the Laser Joint tool.

Take any two parts you want to have a finger joint, make sure they’re the same thickness, and have them intersect. Then open the feature script, select the two parts, and BOOM you have a laser joint. Play with the number of pins to maximize engagement but minimize cut time and you’re off to the races!

Quick tip: provide negative 10 thou of offset to compensate for the burned wood (kerf) that is removed. Note that every laser cutter is different so you may want to do some small-scale tests of this value to tune it to whatever laser cutter you’re using.