PROJECTS: GEARED CANDLEHOLDER
Creating
a Movement
A geared movement raises
and lowers the candles
via parallelogram-linkage
arms that keep the
candles level.
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makezine.com/21/candleholder
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2
4
4
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An 8-tooth drive gear or pinion gear 1 turns 15- and 24-tooth driven gears 2, each of which
moves a different arm. The 2 driven gears have a
gearing ratio of 5: 8, so the 2 candleholders reach the
same relative position, such as maximum height, with
every 8 revolutions of the smaller gear or every 5 of
the larger one. Either way, it takes 120 teeth for an arm
to transit its full range of motion, which corresponds
to 15 full turns of the drive gear knob.
Movable parallel arms 3 hold the candles, using
the same principle as the classic Luxo L- 1 desk lamp:
the 4-bar, parallelogram linkage. On each arm, the lower
pair of pivot points and the upper pair of candleholder
anchor points are both vertical and 1" apart, and it’s
this relationship that keeps the candle cups level in
any arm position.
The gears move the parallel arms by means of a
connecting arm 4, a simple crank linkage that
converts rotary motion to reciprocating (back and
forth) motion.
Illustration by Damien Scogin
88 Make: Volume 21
