Children folding kayak "Yukaghir"

thingiverse

It's my first print-on-demand project, and there are two reasons I did it:\n1) There aren't many folding kayaks for kids.\n2) I needed a simple project to start making kayaks with.\nThis kayak was designed for learning how to paddle on calm water. It's fast enough for a short journey.\nThe type of construction is the same as Triton Ladoga 1, scaled down by 70%. All parts were redesigned to be 3D printable. The original Ladoga 1 uses 20mm and 25mm aluminum alloy tubes and fiberglass-filled plastic connectors. Since non-composite ABS isn't strong enough, I used fiberglass-filled ABS, and PVC tubes without scaling their diameters. This allows me to use two times less material to make a boat that's just as rigid and durable. The second thing I changed is the length of the stern. It's 140mm longer to make the kayak faster and more stable.\nThe main parameters are:\nLength - 3500 mm\nWidth - 450 mm\nSitting place width - 260 mm\nNominal load - 20-30 kg\nMaximum load - 50 kg\nFrames places (from nose, 1,2,3,5,6, in mm) - 620, 1180, 1740, 2310, 2900\n(The 4th frame is an additional one needed for sitting place mounting and its place can be different)\nWeight of assembled framework - 4.5 kg\nTotal weight - 7 kg\n3D printer platform for making - 200x200 mm or more.\nThat's all screws:\nM4 bolts:\n45mm - 5pcs\n35mm - 3pcs\n30mm - 4pcs\n25mm - 2 pcs\nM4 nuts, self-fixing - 6pcs\nM4 nuts - 7pcs\n4mm washers - 12pcs.\nAlso, you'll need PVC tubes. I used 25mm OD 22mm ID - 5x2m and 20mm OD 17.5mm ID - 12x2m. If you can find 3m length tubes, it will make less waste. And, you'll need about 200ml of good plastic glue. I used "Moment crystal".\nFor the "skin", I used PVC coated synthetic fabric 0.65 kg per m2, black for the hull and yellow for the deck and sponsors. They're different only in color.\nThe hull material spreads along the body and cuts to form sterns. It's a good idea to assemble the frame on tape to be 2-3 cm shorter, then it will fit when doing this operation.\nIt's easier to glue the fabric first, and then sew them with strong thread.\nFor sterns watertight and more durable I glued a 10cm wide band of that black fabric along the keel and sterns.\nI cut off the hull fabric at its place, about 3 cm from the upper stringers. Don't tighten the hull and deck fabric across the frame; the air sponsors will do it.\nThe deck material must be tightened along the frame too. First, I glued it, then I did the cockpit hole and sewed the perimeter to the hull. Zippers are needed for assembling and simplifying packing goods.\nAir sponsors are 280 cm long, and about 10 cm in diameter. They don't have to be accurate, but airtight.\nIn assembling the kayak, air sponsor goes from the upper stringer, first frame to lower stringer 3-5 frames and then to the upper stringer, 6th frame.\nThe seat made from 5mm plywood, 24x28 cm, but you can use any.\nThe backrest is a standard one from a kayak (see photo).\nThis kayak is really fast; it goes up to 5 km/h with my son, so I'm planning some little weekend journeys now. \nWarnings:\nDon't heat PVC tubes over 100°C; they will produce VERY TOXIC gases. 80-90°C is enough for forming.\nDon't use if there are more than 150mm high water waves or more than 5 meters per second wind.\nAlways use a life vest.\nThere must be a second boat close to the young paddler while learning.\nUPD 7/3/2017 - paddle added http://www.thingiverse.com/thing:2160535\nUPD 26/6/2017 - skin photos and text