The Thingamejig is a precision scribing tool invented by an Australian cabinet maker who installs millwork and cabinetry. Instead of marking with the usual pencil it scores the material with sharp carbide blades.
The tool consists of a three-winged head with replaceable carbide cutters screwed onto each. A threaded shaft runs through the center, allowing the head to be raised and lowered in relation to the foot—which bears against the surface being scribed to. Once the setting is dialed in the operator secures the shaft with a lock nut.
The scriber has an ergonomic 3-finger grip, making it comfortable to hold and allowing the operator to apply pressure where and when needed. In use, the blades score easily, breaking through the finish so there's no need to worry about chipping. The tool works amazingly well on cross-grain veneer—nearly eliminating the fear of tearing out grain while making the cut. I can usually get a successful scribe in one or two strokes, depending on the hardness of the material. Laminate sometimes takes an extra stroke to break through the surface.
The triangular blades can be rotated to provide three fresh edges. I have been using the Thingamejig for about a year and the blades are ready to be replaced. This is not a tool to be tossed around. Like any precision device, it needs a home and should not be carried in your tool pouch. I dropped it once and chipped a blade. The Thingamejig comes in a snap-top plastic bin, which is a good thing to store it in.
The scriber includes a non-marring plastic cover that fits over the shoe and prevents it from damaging finish surfaces. I use it nearly all of the time and recommend keeping some extras around because they themselves are easily damaged. If you use the scale remember to deduct 1/32 inch for the thickness of the cover. I rarely use the scale; I simply find the largest gap to be scribed and adjust the height of the winged blade, than snug the lock nut.
There are pros and cons to scribing with blades instead of pencils. Blades work best on painted and prefinished material, where the finely scribed line is easy to see. By breaking through the finished surface, the blades make it possible to cut to the line with a jigsaw without having to worry that the finish will flake off (I usually touch up with a belt sander anyway). The Thingamejig is not the best choice for scribing unfinished wood because the finely scribed line is hard to see on that material. I use this tool when scribing to straight, smooth, and flowing surfaces – as when fitting countertops, cabinet fillers, and moldings to ceilings, walls, and floors. The Thingamejig is not an all-purpose scriber and can't be used to scribe around moldings and rough surfaces such as stone. Fortunately, there are plenty of other scribing tools that can do those things.
I liked this "thing" the moment I opened the box. Everything about it says quality: the precise machining, the laser etched scale (metric or imperial) on the shaft, and the triangular carbide blades. With an $80 price tag, this scriber certainly is not for everyone. Some folks will say they can achieve the same result with a $3 compass scriber; they can't – at least not efficiently. The Thingamejig will pay for itself by increasing the quality of your work and reducing the amount of time it takes to do it. If you are like me—a scribing maniac—then you're going to love this tool. It can be purchased at many industry suppliers, which for some reason are mostly located in the Eastern half of the U.S.