Fully functional 114-part tape measure 3D printed in one print run

An aeromechanical engineer has managed to design and 3D print a fully functional, fully assembled tape measure.

Sometimes, you just have to do a thing to see if it can be done. That was the reasoning behind a project by an aeromechanical engineer going by the handle Angry Monk: to 3D print a functional tape measure, fully assembled off the print bed, in just a single print session.

Such a task would not be achievable using the lower-end consumer models, such as those by 3D Systems, that simply use thermoplastic fused deposition modelling; that is, simply laying down filament.

Instead, the technique used is known as stereolithography, or SLA, which involves treating resin material with ultraviolet light in order to cure it. Using an Objet Eden 3D printer (starting at around US$100,000 for the lowest model), the process in this case consists of spraying the resin onto the build tray in microfine layers, curing each one with a UV laser according to the blueprint before adding the next. This allows the printing of fully assembled, articulated objects that can be handled immediately, with a gel-like support material that can be simply rinsed off in water.

Angry Monk's tape measure, with four feet (122 centimetres) of tape, is constructed of 114 separate parts. This includes the case of the tape measure, the tape itself with individual links, a fold-out crank for winding the tape back inside the case, a lock and a belt clip. The crank, lock and clip were all stress tested to make sure they wouldn't break, since the resin itself is fairly brittle.

"I would really have liked to print a one-piece flexible tape or even a spring retractable tape but due to limitations in printing technology and material (and me not wanting to turn this into a giant research project) I couldn't do that," Angry Monk wrote on his blog. "Springs are one of the things that are difficult to print, especially in a brittle material. Springs with a preload are, as far as I know, impossible to print."

The tape measure itself isn't, as Angry Monk notes, of much practical use; but the fact that it is possible to 3D print a fully assembled, 114-part object is pretty danged cool indeed.

Check it out for yourself in Angry Monk's video below.