BY CONOR MIHELL
This spring, thousands of paddling enthusiasts will christen homebuilt canoes and kayaks, crafted over the course of dozens of long winter nights. Amidst the usual cedar-strip, skin-on-frame and plywood boats, Charlotte, N.C.-based engineer Jim Smith’s off-season creation is unique. Smith, the 26-year-old force behind Grass Roots Engineering, claims to have crafted the world’s first 3D kayak for sea kayaking.
Smith modified the Siskiwit Bay, a 16-foot, 8-inch sea kayak designed by Minnesota’s Bryan Hansel, to be produced by his custom-made 3D printer. Over 42 days, he printed the kayak in 28 parts of ABS plastic. Then, he assembled the pieces with machine screws and silicone in his living room. All told, the multi-colored kayak weighs 65 pounds. Smith tallied his costs at $500.
CanoeKayak.com: Where did you get the idea to use a 3D printer to build a kayak?
Jim Smith: I had designed and built my own large-scale 3D printer. I really wanted to print something that would demonstrate the potential of 3D printing and customization for an individual. I had always enjoyed kayaking and since I live on a lake, a custom kayak would work perfectly.
Tell me about the design of the boat. Why did you choose it and why did you need to modify the original Bryan Hansel design?
I chose it because it was a proven design, and the widest sections of the kayak allowed them to be printed in only two pieces. One I generated a 3D kayak model from the 2D plans, I tweaked the width a little bit so It would be a little more stable for me. I have a 10-foot Necky kayak that I am used to. I then had to chop up the design into 28 sections so that each section would take up the maximum build volume of my 3D printer. Since I was trying to save on material, I made the hull six millimeters [thick], and thus I had to design in a interior rib structure to give the kayak more strength. I also had to design the interfaces between each section so they could be bolted together.
How do you put all the parts together?
One side of each section has brass threaded thermoplastic inserts pressed into them with a soldering iron. These are internally threaded so that a bolt can be screwed into it. The mating section has through-holes for bolts. Before I put each section together I use silicone caulk to section each section as I bolt them together.
What’s it like to paddle?
It is really awesome to paddle and way faster than my little 10-foot Necky kayak.
In your opinion, what is the future of 3D printing and watercraft?
I suppose that the future of 3D printing and watercraft is customization. You can tweak the design of a kayak to optimize its performance for your body and intended use.
Photos courtesy Jim Smith, grassrootsengineering.com