1. DESIGN A FRAME.
Lacking a welder, we began sketching a
frame made of 2× 4 lumber. For the steering,
we originally thought of “Frankensteining” a
recovered bicycle front fork onto our wooden
frame and putting the 2 drive wheels in back.
But the more we looked at it, the more it just
seemed heavy and inelegant (Figure A).
So we decided to replace the front fork with
a rear caster and bring the 2 paired wheels in
front, like on a “tadpole” trike. But they would
also be the drive wheels, and you’d steer tank-style by accelerating one motor or the other!
We all liked this idea, as it drastically raised
the crazy factor of our kart.
We originally envisioned dropping the
drive wheels between wooden forks, but the
open wood forks on this “box with wings”
just weren’t strong enough (Figure B). So we
decided to box the wheels in (Figure C).
This design also leaves room to install
foot brakes at the kart’s front edge. You can
size your kart by test-fitting the seat and its
distance to your imagined foot brakes. Once
you’ve located the seat, you’ll know roughly
where to mount the drills for comfortable
driving, and thus how big to make your frame.
2. BUILD THE FRAME.
Our frame is a big rectangle with internal
braces to support the wheels and driver, plus
a triangular rear extension to stiffen the long
central tailpiece that holds the rear caster.
Cut the 2×4s to length, lay them out, and
mark where the wheel axles will go. Use the
2" Forstner bit to drill 2 dropout grooves for
each axle. Screw the frame together with 2½"
wood screws or deck screws (Figure D).
3. MOUNT THE WHEELS AND DECK.
Flip the frame upside down. Lay an axle in its
dropouts, center a bracket over each dropout,
mark and drill the bolt holes through the 2× 4,
then bolt the brackets on (Figure E). You can
unbolt them to remove the wheel.
Bolt the caster to the tail of the frame. You’ll
probably have to add wood blocks in between
to make it level (Figure F).
Finally, cut a ½" plywood deck to cover
your frame, and screw it down with 1" wood
screws (Figure G).
Drawings by Gever Tulley
4. MAKE THE BRAKES.
We settled on simple wooden brakes that rub
on the tires, with foot pedals for leverage.
42 Make: makezine.com/26