Step Gear Project
A card project to print out and make.
I’m not sure if these gears have an official name, but I’ve settled on step gears because of the step in the middle. Here’s the idea:
In a standard geared mechanism you can step up or step down the gear ratio by pairing a large gear and a small gear back‑to‑back. In this mechanism I wanted to step up the ratio while keeping everything flat. To do that, I effectively cut two gears, one large and one small, in half and glued them together. The result is that as six teeth pass the small gear, the output moves fifteen teeth. Connect that to an output pinion and watch it spin! The downside is that you can’t do more than half a rotation but, hey, it still makes for a fun project.
I designed the project using my old favourite, the Gear Generator program from Matthias Wandel’s woodgear.ca website. I created a twelve‑tooth and a thirty‑tooth gear with twelve‑millimetre teeth, pasted the parts on top of each other, then drew in the connecting line between the two in pencil. After that, I glued the template to some corrugated card and cut it out.
The lever arm uses a section from a twenty tooth gear, again I pasted onto card and drew in the rest of the lines before cutting it out.
Once I’d established that everything worked as intended I transferred the parts to my computer, printed, pasted and cut them out ready for action.
After which it was the usual path of photography, video, instruction and posting the result to www.robives.com where it is available to download as a pdf.
As always, if you’re a premium subscriber to this newsletter, the project file is waiting for you at the foot of the page ready for you to download and have a go. Thank you for supporting my work and for following along with these little adventures in cardboard and mechanics. I hope you enjoy the project, and I hope the week ahead brings you lots of maker fun. And if you haven’t subscribed yet, do consider signing up, there’s plenty more to come as well as plenty in the back catalogue.