It doesn't seem too long ago that 3D-printers were astounding us by churning out cheeky little trinkets or small replacement parts. But the technology has quickly grown to cater for everything from rapid prototyping to slick-looking commercial products, and a quick snack for astronauts to bizarre models of unborn babies. Jim Smith of Grass Roots Engineering has been designing and building his own home-based, large-scale 3D printer since 2008, and the latest modification recently spent over 40 days producing 28 colorful ABS plastic sections that were bolted together to create a 16.7 ft-long kayak.

The 3D-printed kayak design was based on the Siskiwit Bay kayak by Bryan Hansel, but modified for 3D-printing and optimized for Smith's height and weight. It's 16.7 ft (5.08 m) long and 1.7 ft (0.52 m) wide, with 28 sections that have been bolted together with machine screws and brass-threaded thermoplastic inserts, and sealed between sections with silicone caulk.

Smith, who works as an engineer at 3D Systems, modified his custom large-scale 3D printer to produce the large sections inside a heated chamber, to prevent warping and cracking. The heat from the build surface kept the chamber between 65 and 70 °C (149 - 158 °F). The largest section, section 15, measures 15 x 9 x 11 in (381 x 229 x 275 mm) and weighs 3.32 lb (1.5 kg).

The sections took a total of 1,012.65 hours (just over 42 days) to produce, at a layer height of 0.65 mm to keep print time down. Smith has added points to attach cameras, handles and future unspecified add-ons. The finished craft tips the scales at a not-exactly-featherweight 64.58 lb (29.29 kg), of which just over 58 lb is ABS plastic, but as you can see from the project overview video below, it does float.

Source: Grass Roots Engineering