Santa, You Elegant Bastard

Wind-Up Car with DOOM! Recognition

Santa and his Elves are often portrayed as the last bastion of the classic toy. You know, the solid wood thing with no parts that move on their own, no Allen wrenches for assembly, and makes Dad’s back hurt as he hauls it trans-Atlantically back home after celebrating the holidays with family back in the States because solid wood is heavy. The kind of toy that is powered not by batteries but by imagination[1].

Technically, the toy that blew my mind with its elegant simplicity does have moving parts, but it does not use any of those new fangled electronical circuits based on quantum mechanics[2] that all the hot gizmos and doo-hickeys use. “It” being a wind-up toy car that knows to turn to avoid falling off the edge of a table. It is what we call “elegant”. Figuring out how it worked[4] was as much fun as actually using it. “It” being a wind-up toy car that knows to turn to avoid falling off the edge of a table.

How does it work? Very simply. Power comes from the winding of a spring that the user winds by the little handle-knob thingy sticking out of Speed Racer‘s noodle.

The Undercarriage

The unwinding spring drives the two rear wheels (drive wheels) moving the car straight ahead. On a flat table, the two front wheels are in contact with the table and the car moves forward. The fifth wheel is located between the front and rear wheels, is oriented perpendicular to the four main wheels, and is continually driven by the spring. Critically, the perpendicular wheel is slightly recessed, which means that, on a flat table with the other four wheels on the table, the perpendicular wheel does not make contact with the ground. When the front wheels, however, run off the edge of the table, the car tilts forward bringing the perpendicular wheel onto the table and turning the car right until the front wheels are both back on the table. The front wheels are conical on both sides, preventing these wheels from catching as they remount the table, and the axle is allowed to wobble, insuring that the perpendicular wheel stays in contact with the table until both front wheels are back on the table.


My human children (hell, my human self) have far more complex and less reliable precipitous-drop-to-DOOM! detection and avoidance systems; which goes to show you that natural selection in the wind-up toy car market is may be far more efficient[4] than in humans.


  1. Ain’t that sweet[5].
  2. Although, as Santa’s delivery schedule clearly requires advanced knowledge of quantum mechanics and space-time, it hurts a little that he is so unwilling to share any fruits of his knowledge. Perhaps there is a Yuletide Prime Directive?
  3. The Familial Ethics Committee did not approve the dissection arm of the planned study, but did approve the observational arm.
  4. The selection pressure may not itself be more intense. One could reasonably propose that the effective population size of wind-up toy cars has, in the relatively recent history (although maybe not today), is larger than that of humans.
  5. Cause you know the modern era, with its sanitation, vaccines, antibiotics, and cellular mobile telephonic devices, is the harbinger of Armageddon.

Author: Josh Witten

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