Last week, Michael Stevens posted a fascinating video about Genaille-Lucas Rulers, a 19th-century tool to simplify multiplication and division.

It’s the kind of thing that’s just begging to be made on a Glowforge (the set in the video was laser-cut by Creative Crafthouse), so I thought I’d give it a whirl.

I started out with the SVGs on the Wikipedia page linked above, but they’re designed to the printed on paper and cut out, not laser-cut. So I re-drew my own versions from scratch.

(*Note*: SVGs re-uploaded Jan 17, 2018 at 2:33:02 PM PST to fix a minor error)

Multiplication:

Division:

I decided to make mine with the multiplication version on one side and the division on the back. To keep everything aligned, I used a combined SVG with everything in separate colors:

Engrave/score/cut the multiplication side (while ignoring the division stuff), then flip the rulers and engrave & score the division side (ignoring the multiplication stuff).

I used Thick Cherry Plywood. The numbers and text are all engraved with the “HD Graphic” setting. The triangles on the multiplication side are SD engraved and all of the lines are HQ scored. Before cutting the whole project, I created a single test ruler with a variety of settings for the engrave:

I preferred one of my manual engrave settings, but the rest of my family was unanimous in their preference for SD Engrave.