Elektor SAND CLOCK, Assembly Manual

Page: 3 / 31

Step 11 – 12
Remove the protective film from the acrylic parts. Attach the lift servo to lift servo panel (D)
using two M2x10 machine screws [3] and M2 nuts [3]. Attach the servo horn to the servo
shaft using the M2.5 machine screw packed together with the servo accessories.
The servo horn should point more or less upright at an angle of 90 degrees. Don't worry if
you can't get it exactly at 90 degrees due to the teeth of the servo shaft and the servo
horn.
The acrylic lift servo lever (E) has 2 holes. Screw it with the smallest hole to the servo horn
using a self tapping plastic screw from the servo accessories bag. Tighten the screw so
the lever can turn freely with as little slack as possible. The distance between the center of
the servo shaft and the mounting point of the lever should be +/- 13 mm. This is usually the
second last or third last hole in the servo horn.
Step 13 – 17
Attach the lift servo mechanism to the frame using an M3x10 machine screw [3] and an
M3 nut [3]. Mount the Arduino Uno to the base plate using M2.5x8 machine screws [3] and
3 mm plastic spacers [3]. Tighten the screws loosely so the Arduino can still move a bit.
Note that the screws are tapped into the base plate, nuts aren't required. Now attach the
frame with the lift servo mechanism to the bottom plate using two M3x10 machine screws
[3] and an M3 nut [3]. Finally tighten the Arduino mounting screws.
Step 18 – 19
Connect the shield to the Arduino and insert a CR2032 3 V lithium coin cell into the battery
holder.
Step 20 – 23
Attach the hinges (H) and (G) to the pantograph servo motors mounting plate (F) using
M3x10 machine screws [4] and M3 nuts [4].
Mount both servo motors using M2x10 machine screws [4] and M2 nuts [4].
Step 24 – 26
Attach the pantograph servo mechanism to the base of the clock using 2 M3x10 machine
screws [4] and 2 M3 lock nuts [4]. Tighten the screws so the pantograph mechanism can
rotate freely with as little slack as possible. Route the servo wires under the lift servo and
connect them to the Arduino shield. Turn the pantograph servo mechanism upright and
attach it to the lift servo lever using an M3x10 machine screw [4] and a M3 lock nut [4].
Tighten so the mechanism can operate freely with as little slack as possible.
Step 27 – 28
Assemble the pantograph arms. Screw part (J) on top of one of the parts (I) using an M3x8
machine screw [4]. Then screw part (K) on top of part (J) using an M3x8 machine screw
[4]. Finally screw the other side of part (K) on top of the second part (I) with the round
acrylic disc (L) in between using an M3x10 machine screw [4]. Tighten the screws so the