Chances are you already need a steel ruler for your fixing and making tasks, so why not use one that can do much more than most? That's the idea behind the ten-function Tiruler, which packs a protractor, caliper, bubble level and even a wrench.
Currently the subject of a Kickstarter campaign, the titanium-bodied folding Tiruler is made by Hong Kong company MakerPi. First and foremost, the device can indeed serve as a straight-edge ruler, for measuring, drawing or cutting straight lines.
The markings on the beveled edges of its two arms go up to 100 mm on one side and 3.94 inches on the other. For working with longer lines, the arms can be folded out to their full combined 200-mm/7.88-inch length. Magnets in the arms help keep them folded together otherwise.
For measuring lines or surfaces that aren't straight, the wheel/hinge that connects the arms also serves as a measuring wheel. One rotation of that wheel equals 100 mm, with an audible click indicating each full rotation. A silicone ring in the wheel is claimed to keep it rolling smoothly.
The wheel additionally allows the Tiruler to function as a 180-degree protractor, by showing the numerical value of angles that are being either drawn or measured. The folding action of the ruler also lets you draw perfect circles of various radii, by sticking the tip of a pen or pencil in one of a number of marked holes in one of the arms, then swinging it around.
If you don't have a writing instrument close at hand, the Tiruler comes with a graphite-tipped "everlasting pencil" that is retained in a groove in the device via integrated magnets. The non-writing end of that pencil features a blunt blade for tasks such as opening cardboard boxes.
For really precise measuring jobs, there's a vernier caliper that slides out the end of one of the arms. It features two sets of numerical markings, one for full millimeters and one for tenths of millimeters.
Other features include the previously-mentioned bubble level, a bottle opener, and a hex wrench hole that accepts third-party quarter-inch bits. The whole rig is claimed to tip the scales at 60.7 g (2.1 oz).
Assuming the MakerPi Tiruler reaches production, a pledge of US$84 will get you one. The planned retail price is $138.
Its functions are demonstrated in the video below.
Source: Kickstarter