555 Timer Dancing Dinosaur
by cheapmechanics in Workshop > Metalworking
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555 Timer Dancing Dinosaur
This instructable is about a dancing mechanical sculpture that represents a Triceratops dinosaur. The dinosaur is nodding its head and dancing to music in the first video (2 minutes and 50 seconds). The other two videos are about 15 seconds.
The metal wire sculpture will take you a whole day to make. The 555 timer circuit will take two hours to make.
Supplies
Supplies: 1.5 mm thickness metal wire (I used 1.2 mm thickness, the maximum thickness should be 2 mm if you cannot find 1.5 mm metal wire), 1 mm metal wire for joining the 1.5 mm metal wire, 555 timer IC - 2 (you might need a spare), wire wrap socket - 1, wire wrap wire (pack of 20 cuts or spool), small matrix board - 1, 100 kohm variable resistor - 1, 1.5 kohm resistors - 2, 10 nF ceramic capacitor - 1, 47 uF electrolytic capacitor - 1, insulated wires, 6 V power block (made from four AA batteries) - 2, 10-ohm power (1 Watt) resistor - 1, general purpose diodes - 10 (you might need spare).
Optional supplies: Encasement (cardboard or plastic box), SPST switch, solder, thin rope or string.
Tools: Wire wrap tool, pliers, scissors.
Optional tools: wire stripper, additional pliers, multi-meter, soldering iron, electric drill (to drill holes in the plastic box).
Software: PSpice student edition version 9.1, Octave software, or scientific calculator app on your phone.
Design the Circuit
This simple 555-timer circuit is designed to supply positive and negative voltages to the motor. The potentiometer is used to control how often the voltage output changes in polarity. This change in polarity makes the motor move clockwise and anticlockwise (seen in the video).
The diode protection circuit is needed to protect the 555 timers from discharging motor currents. This can happen if you move the motor when the circuit is OFF.
You can look up 555 timer frequency calculations online. I also created this Matlab code to calculate the component values:
% 555 Timer Components Calculations
clear all;close all
C1=47*10^-6
R1=1500
R2=1500
R2pot=100000
R2min=R2;
R2max=R2+R2pot;
Tmin=0.693*(R1+2*R2min)*C1;
Tmax=0.693*(R1+2*R2max)*C1;
disp(['Minimum Period = ' num2str(Tmin) ' seconds'])
disp(['Maximum Period = ' num2str(Tmax) ' seconds'])
Because I do not have Matlab at home I used the free Octave software to obtain the following output:
C1 = 4.7000e-05
R1 = 1500
R2 = 1500
R2pot = 100000
Minimum Period = 0.14657 seconds
Maximum Period = 6.6608 seconds
Simulations
I used PSpice student edition version 9.1 to draw and simulate this circuit.
Simulations show that the 555 timer is supplying the motor with 1.5 V and -2 V square waveform.
The magnitude of maximum voltage (1.5 V) is smaller than the magnitude of minimum voltage (2 V) because of the 555 timer maximum output voltage limitations.
Make the Circuit
I made the circuit with wire wrap. I did not use a soldering iron. I wrapped the wire wrap around the component legs. You can also twist the component legs to join two or more components together like you do with wires.
Encasement
I used scissors to cut a hole in the cardboard box for the potentiometer.
Make the Torso
I made the torso from one whole piece of 1.2 mm metal wire. However, you can cut the thick wire into pieces and join them with thin (1 mm) wire. You will see examples in the next few steps.
Make the Legs
The legs were made from 1.2 mm metal wire.
Attach the Legs
You can see how I attached the legs to the torse with 1 mm thickness metal wire. You might need additional pliers for this step.
Make the Head
You can see how I joined pieces of thick metal wire by winding thin (1 mm) metal wire around them. You might need additional pliers for this step.
Attach the Head
If you look at the first photo in this step you will see that I attached a metal wire to the back of the head. This wire is used as a fixture. Then I used a 1 mm thickness metal wire to attach the head to the torso.
Attach the Gear Motor
I put a wire through the holes of the gear motor to attach it to the back of the dinosaur. The space in the front can be used for the circuit.
Attach the Wheel
I attached the wheel and connected a thin wire from the top of the head to the wheel. You can use a thin rope or string.
Testing
The sculpture worked.