Bicycle clock: big pictures and notes
pictures parked here
| Materials used: bike parts, masonite, skate board bearings, copper plumbing parts, nuts and
bolts.
The bearings fit snugly over 5/16" threaded rod, and they happen to fit snugly inside copper
pipe fittings which have ID of 7/8". No machining necessary.
IMG_5883.JPG |
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| A 12V DC motor, running at 60 RPM, advances a wheel one tooth per second. This drives the
chain that supports the rest of the clock.
IMG_5866.JPG |
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| IMG_5867.JPG |
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| IMG_5868.JPG |
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| IMG_5869.JPG |
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| IMG_5870.JPG |
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| IMG_5871.JPG |
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| IMG_5872.JPG |
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| This shows the 3 nested axes, the innermost one, a 5/16" threaded rod holds the second hand,
the next one, running on bearings, holds the minute hand, and the hour hand running outside of
that.
IMG_5873.JPG |
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| IMG_5876.JPG |
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| Closeup of the drive mechanism. The finger switch is a later addition: an Arduino counts
the number of clicks it sees. If it is less than 60/min, it increades the voltage to the DC motor,
and vice versa. This makes the clock as accurate as the internal oscillator of the Arduino.
IMG_5877.JPG |
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| By necessity most of the gears end up between the suspension chain and the clock face,
which is to the right in this picture. A bicycle wheel, on the left, serves as a counterbalance. It can
rotate freely.
IMG_5878.JPG |
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| On the very bottom is a dead weight that serves to keep some tension on the lower chains.
It consists of an axle with chain wrapped around it.
IMG_5880.JPG |
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| The clock face is independently suspended from the handlebars. Wheel rim, chicken wire,
beer can cutouts.
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Hubert van Hecke Last modified: Sun Nov 26 14:39:51 MST 2017