If there’s one thing that woodworkers have always been good at, it’s coming up with clever jigs and work-holding solutions. Most jigs, however, are considerably simpler and more static than this CNC-controlled scroll saw add-on that makes cool wooden spirals a snap.
As interesting as the products of this setup are, what we like about this is the obvious care and craftsmanship [rschoenm] put into making what amounts to a hybrid between a scroll saw and a lathe. Scroll saws are normally used to make narrow-kerf cuts in thin, delicate materials, often with complicated designs using very tight radius turns. In this case, though, stock is held between centers on the lathe-like carriage. The jig uses a linear slide driven by a stepper and a lead screw to translate the workpiece perpendicular to the scroll saw blade while a geared headstock rotates it. Starting with the blade inserted into a through-hole, the saw slowly cuts a beautiful nested spiral down the length of the workpiece. An Uno, a GRBL shield, and some stepper drivers let a little G-code control the two axes of the jig.
The video below shows it in action; things do get a bit wobbly as the cut progresses, but in general the jig works wonderfully and results in some lovely pieces. At first we thought these would purely be objets d’art, but then we thought about this compression screw grinder for DIY injection molding machines and realized these wooden screws look pretty similar.