You are here

Joe Harmon, builder of the high-performance supercar

What weighs 2,500 pounds, goes well over 200 miles per hour, and is made almost entirely out of wood? No, it's not the setup to a bad joke. It's Splinter, an ambitious—and entirely serious—wooden supercar.

Submitted by WOOD community member WOOD Magazine StaffSubmit a Shop Guide
  • Splinter, the high-performance wooden supercar

    Splinter was conceived, designed, and built by North Carolina State University graduate student Joe Harmon and his talented team in Joe's backyard shop in Durham, North Carolina. Talking to Joe, you get the impression that he has heard the skeptical termite taunts and canoe comparisons before. And that he understands the best way to disarm critics is with his half-smile and a just-the-facts recitation of his creation's statistics. (See stats, next slide.) With an estimated weight slightly greater than a Cooper Mini and a projected top speed faster than a Porsche, Ferrari, or Lamborghini, this car will fly. And aside from the engine, transaxle, and a few connecting parts, the car is made completely of wood.

  • A look under the wood hood

    Engine: 700-hp, highly customized, twin super-charged, quad intercooled Cadillac Northstar V8 with reversed cylinder heads and custom exhaust

    Drivetrain: 6-speed manual Corvette transaxle

    Layout: Mid-engine, rear-wheel drive

    Chassis: Monocoque (integrated chassis and body) design

    Projected Weight: 2,500 lbs

    Projected Top Speed: Greater than 200 mph

    Wheelbase: 105"

    Length: 174 1/2"

    Width: 82"

    Height: 42"

    Ground Clearance: 3 1/2"

    Parts made of wood: Chassis, superstructure, body, interior panels, wheels, steering wheel, and much of the front and rear suspension—pretty tmuch everything.

  • The splinter team

    Pictured counterclockwise from front left are Joe Hunt, Brownie, Joe Harmon, Caroline Sulatycki, Aaron Nace, Zac deBethizy, Ben Bruzga, and Luke Jenkins. Not pictured: Kendal Draper.

  • Borrowed from bow-makers

    Joe and his crew made Splinter's 400 inch-lb. leaf spring from laminated osage orange. Bow-makers prize this tough wood for its strength and flexibility. Joe had to travel to Kentucky to find logs large enough to yield useful veneer. The logs were so hard that they threw sparks and damaged blades as they were being rotary-cut into veneer sheets.

  • This ain't no wagon wheel

    The wheels were the first parts to be completed. For rotational strength, the grain direction of each of the 300 layers of oak veneer is rotated 36° from the previous layer.

  • A design and a dream

    Long before they touched a tool, the team created realistic 3D computer renderings. Several manufacturers agreed to donate materials based on these pictures alone.

  • Heavily modified engine

    Early in the project, Joe Hunt reversed the cylinder heads on the Northstar engine, a setup that required custom manifolds, superchargers, and exhaust system.

  • Glue, glue everywhere

    Nearly all wood-to-wood surfaces were joined with epoxy alone. Metal fasteners were used mainly to temporarily hold joints while the epoxy cured.

  • A classy wood chassis

    The Splinter team used wood throughout the chassis. The surprisingly rigid laminations were even used in the critical truss and roll bar shown here.

  • Flexible layers form rigid compound curves

    Body panels, such as the butterfly panel, are made up of tessellated end-grain balsa laminated between layers of woven cherry and bamboo.

  • Weaving wood

    Luke, left, and Ben hand-weave 1"-wide cherry-veneer strips that will cover the curved dashboard. The weave will be saturated with clear epoxy, then vacuum-bagged.

  • Tessellated balsa

    Mesh backing allows this sheet of end-grain balsa blocks to conform to the curves of the body panels, building thickness while keeping the weight down.

  • Foam mock-up

    After the chassis was assembled, extruded polystyrene foam blocks were cut to fit around it, then carved into shape with a hot wire and a grinder.

  • Sculpting the splinter

    Joe and Zac use 3D coordinate points taken from the foam mock-up to create the wooden master mold from which fiberglass body-panel molds will be cast.

  • Fiberglass body molds

    Joe displays the fiberglass body-panel mold for the nose of the car freshly pulled from the wooden master mold. The team will wax the mold before using it for laminating veneer.

  • One more layer

    Joe Hunt epoxies the last structural layer, woven bamboo veneer, to the interior of a butterfly panel. The mold is then bound for a large vacuum-bag press.

  • Advanced basket weaving

    With a growing need for woven veneer, the team built a custom loom that slashed days from the veneer-strip weaving process and allowed for smaller, tighter wooden weaves.

  • Approaching the finish line

    The saying, "That car is cherry" is not just an idiom for Splinter. Tightly woven cherry-veneer strips make possible the stylish curves of Splinter's assembled body panels.

  • Joe Harmon, builder of the high-performance supercar

    Splinter, the 700-horsepower supercar, features a chassis, suspension, and body fabricated almost entirely out of wood laminations. Complex chassis parts required custom molds and shop-made vacuum presses. And sleek body panels with compound curves employed creative veneering to ensure a beautiful and surprisingly rigid exterior.

Read more about

Tip of the Day

Drill Evenly Spaced Holes with Speed and Accuracy

Drill Evenly Spaced

Sometimes you need to drill evenly spaced holes. If you have a ruler at least half as long as your... read more