A team of engineers from the Hasso Plattner Institute in Potsdam, Germany wanted an easy way to build sketch models at a large scale. They wanted something that could build larger than 3D printing and be done much faster. They developed the Protopiper to physically sketch room sized objects at scale, and presented their paper at User Interface Software and Technology Symposium 2015 last month in Charlotte, North Carolina.
Protopiper takes adhesive plastic tape and extrudes it into a tube shape, giving a great strength to weight ratio and allowing for an easy scale up to large structures. Tubes can have wing connectors, hinges, or flat ends. The adhesive on the tape eliminates the need for cooling that comes from traditional 3D printing, and the tubes print much faster. The Prototpiper device itself is designed to be handled by one user, although the video shows two people involved in a large scale assembly process. The limitations of the device are few - the tape’s adhesive sticking to itself when a load is applied perpendicular to the tube’s axis. The design intent is for straight, stiff components, so when a curved surface is required several small pieces must be put together to approximate the desired contour.
The unit itself works a little like a 3D printer – two gears pull the tape through the device and two extrusion stencils shape the tape into a tube. The tape has a backing layer that peels off, and the backing layer is spun backward onto a spool as the tape is pulled through the mechanism. Hot wires are used to cut the tube to the desired length or cut the wing shape in for connecting the tube to another object. Everything is powered by a 1000 milli Amp-hour lithium polymer battery, and one battery charge gives between 100 and 200 cuts. A four character display on the side of the Protopiper shows users which function is currently being run on the machine and length of the current tube.
Protopiper looks like an incredible machine that would easily allow users to build large scale sketch models. The videos and information online make the operation look much easier than I expect it would be for me, but the builds in the video look fast and painless. There is no indication that the institute will mass produce and sell the Protopiper but it would be a great tool for use here at my college or in many industrial environments. Harshit Agrawal, Udayan Umapathi, Robert Kovacs, Forhnhofen Johannes, Hsiang-Tin Chen, Stefanie Mueller and Patrick Baudisch are the authors of the paper presented, all from the Human Computer Interaction Lab at the Institute.