Ami Varsano
Xenon’s Glow—The Physics of Inductively Coupled Plasma
updated
The zoetrope, invented in 1834 is another early animation device that creates an optical illusion of motion. Unlike the phenakistoscope, which only allows one viewer to see the motion of images, the zoetrope allows several viewers to see the optical illusion of moving images. The zoetrope and phenakistoscope were also animated with a stroboscope.
In recent years, digitized phenakistoscopes have become popular. These are created with animation software where a phenakistoscope disc is made to rotate while the entire disc is sampled at a calculated frame rate to display the animation. This technique has been used to create digital versions of classic phenakistoscopes as well as new animations.
Timestamps
00:25: Phenakistoscope run by an electrostatic motor
00:55: Digitized animation
01:20: Zoetrope animating a galloping horse
02:55: Digitized animation of a galloping horse with increasing speed
03:31 Phenakistoscope animating a swirling spiral
04:44: A view of the DC gear motor from a paper towel dispenser.
05:19: Digitized animation of a swirling spiral
Music
Title: Piano Sonata No. 11 in A major, K. 331 “Rondo Alla Turca”
Composer: Wolfgang Amadeus Mozart
Artist: Marnie Laird for Brooklyn Classical, Piano, Oct. 23, 2018
Title: Light Cavalry Overture
Composer: Franz von Suppé
Artist: Berlin Philharmonic, conductor: Herbert von Karajan, 1985
A Lego Walker is displayed at the end of the video. That eight-legged ‘creature’ is powered by a 9-volt battery and runs on a Lego Technic Power Functions M-Motor (8883).
Timestamps
00:00 Inline biped walking on leveled ground.
00:15 Inline biped climbing a hill.
00:30 Inline biped walking downhill.
00:45 Inline biped departing the scene.
00:53 Quadruped walking on leveled ground.
01:08 Quadruped climbing a hill.
01:23 Quadruped walking downhill.
01:38 Quadruped departing the scene.
01:46 Eight-legged Lego walking on leveled ground.
Music
Title: La gazza ladra, opera overture
Composer: Gioacchino Rossini
Artists: Orchestra del Teatro La Fenice. Conductor: Daniel Harding, 2015
Watch other walkers in action:
Lego Tumbling Acrobat Automaton: http://youtu.be/KELP9SjrSn0
Lego Passive Dynamic Walker: youtu.be/j1BZ128YU9I
Lego Tumbling Automaton: youtu.be/VXvezNiOlGc
I owe a debt of gratitude to Professor Emeritus S. M. Blinder from the University of Michigan for creating the animation model that I adapted into a Monte Carlo simulation with statistical analysis. I added features such as automated random variations of the launch vector, a scrolling scoreboard that displays the angles, speeds, and outcomes as “Hit” with a sound, or “Miss”, and fixed the position of the player behind the Free Throw Line.
Time Stamps
01:00 Optimizing Basketball Shots in 3 Steps
00:25 Flowchart
00:55 Step 1: Simulate with a Wide Range of Angles and Speeds
01:10 Examples with Still pictures
01:25 Three Animations with a Wide Range of Angles and Speeds
02:24 Step 2: Statistical Analysis with Scatter Plot
02:44 Animated Scatter Defines the Narrow Range of Angles and Speeds
03:30 Step 3: Simulate with a Refined Range Angles and Speeds
03:55 Three Animations with a Narrow Range of Angles and Speeds
Music
Title: Nocturne in E-Flat Major, Op. 9, No. 2
Composer: Frédéric Chopin
Artist: Marnie Laird for Brooklyn Classical, Piano, Oct 23, 2018
Chapters
00:00 Introduction
00:24 Scrolling Text
00:43 Illustration of a Light Chaser
01:09 Light Chaser in Slow Motion
01:24 Shorter Timing Sequence of Light Chaser
01:39 Simulation of Motion
01:55 Hand-Held Fan
02:09 Red Ring
02:25 4-Color Ring
02:40 3D Ring
02:55 Concentric Rings
03:08 Radial & Centripetal Motion
03:23 3-Color Hub & Spokes
03:37 4-Color Hub & Spokes
03:52 Hub & Spokes in a Ring
04:07 Sine Function
04:18 4-Color Sine Function
04:38 Wave Pendulum in a Ring
Watch animations with a similar style to this video:
Wave Pendulum Collection: youtu.be/RKJ1Taridy0
Wave Pendulum Animation: youtu.be/VQlKryLe33c
Music
Title: Down The Street Blues
Artist: Unicorn Heads
Album: River Radio, Released 2018
Reference:
Wave Pendulum Animation: youtu.be/VQlKryLe33c
Lego Undamped Wave Pendulum: youtu.be/edLS3m49vEE
Lego Damped Wave Pendulum: youtu.be/3sKyTimnGHc
Pendulum Wave Machine: youtu.be/_jSPq8p5eHs
Light Chaser Collection: youtu.be/ow18zsFTJ_8
Chapters
00:00 Introduction
00:13 Wave Pendulum in a Stack of Disks
00:51 Dual Disk Wave Pendulum
01:26 Quad Disk Wave Pendulum
02:09 Horizontal Wave Pendulum
02:54 Cross Wave Pendulum
03:53 Three Wave Pendulums Forming Acute Angles of 20 Degrees
05:10 Ring Wave Pendulum with Disk Pendulum at Center of Ring
05:38 Dual Ring Wave Pendulum
Music
Title: Piano Sonata No 11 in A Major, K. 331, (1st Movement)
Composer: Wolfgang Amadeus Mozart
Artist: Marnie Laird for Brooklyn Classical, Piano
Reference:
Wave Pendulum Collection: youtu.be/RKJ1Taridy0
Lego Undamped Wave Pendulum youtu.be/edLS3m49vEE
Lego Damped Wave Pendulum: youtu.be/3sKyTimnGHc
Pendulum Wave Machine: youtu.be/_jSPq8p5eHs
Light Chaser Collection: youtu.be/ow18zsFTJ_8
Music
Title: “Nightlife”
Composer and Acoustic Guitar: Michael Kobrin
Album: “Searching”, Released 2016
Mastered at Turtletone Studios, NYC, U.S.A.
The period of one complete cycle is 60 seconds. The longest pendulum was adjusted to complete 52 oscillations in this period. The length of each successive pendulum was adjusted to complete one additional oscillation during this period.
Chapters
01:00 Pendulum wave patterns
01:20 Charging the Glow-in-Dark disks
01:28 Pendulums are lined up and set in motion
01:47 Sinusoidal transverse traveling wave pattern
02:07 Standing wave pattern — full wavelength
02:11 Pendulums are at alternating maximum phases, 30 seconds after they were set in motion
02:13 Standing-wave pattern — half a wavelength
02:28 Sinusoidal transverse traveling wave pattern in the direction opposite to the original one
02:41 Pendulums are ultimately lining in phase (almost…)
03:35 Idling oscillator — no swinging pendulum
03:45 Pendulum-driven by oscillator
04:00 Verifying period of pendulum with photogate
04:24 Description of circuit operation
Watch other wave pendulums in action:
Wave Pendulum Collection: youtu.be/RKJ1Taridy0
Wave Pendulum Animation: youtu.be/VQlKryLe33c
Lego Damped Wave Pendulum: youtu.be/3sKyTimnGHc
Pendulum Wave Machine: youtu.be/_jSPq8p5eHs
Music
Title: "Moonlight" Sonata No. 14, Op. 27, No. 2 (1st movement: Adagio Sostenuto), Aug. 2, 1802
Composer: Ludwig van Beethoven
Artist: Marnie Laird for Brooklyn Classical, Recorded on Oct. 19, 2018
Title: Das klinget so herrlich, Die Zauberflöte, Act 1- Finale, Sep. 1791
Composer: Wolfgang Amadeus Mozart
Artist: Unknown. Played during showcasing a glockenspiel, made by Kolberg Percussion, Kołobrzeg, Germany, 2014
The lengths of the pendulums are adjusted so that their oscillation completes an integer number of cycles in 60 seconds. Each successive shorter pendulum completes one additional oscillation in the same time interval.
Chapters
00:00 Charging the glow in dark disks
00:17 Pendulums are set in motion and are all in phase
00:22 Sinusoidal transverse traveling wave pattern
00:35 Chaotic pattern
00:44 Standing wave pattern: one complete wave in a pattern that consists of two loops
00:47 Pendulums are at alternating maximum phases, 30 seconds after they were set in motion
00:51 Standing-wave loop pattern: one loop is equivalent to one half a wavelength
01:07 Sinusoidal transverse traveling wave pattern in the direction opposite to the original one
01:19 Pendulums are ultimately coming back in phase
Check out other wave pendulums:
Wave Pendulum Collection: youtu.be/RKJ1Taridy0
Wave Pendulum Animation: youtu.be/VQlKryLe33c
Lego Undamped Wave Pendulum: youtu.be/edLS3m49vEE
Pendulum Wave Machine: youtu.be/_jSPq8p5eHs
Music
Title: Das klinget so herrlich, Die Zauberflöte, Act 1- Finale,1791
Composer: Wolfgang Amadeus Mozart
Artist: Unknown. Played during showcasing a glockenspiel, made by Kolberg Percussion,
Kołobrzeg, Germany, 2014
Chapters
00:00 Wind Turbine
00:16 Bifilar Coil
00:36 Rotor and Electronic Circuit
00:56 Turbine Spinning and Flashing LEDs
01:59 Measuring RPM
Circuit Operation — Refer to Schematic Diagram
When the ring magnet spins, its north pole moves closer toward the coil, inducing an electromotive force (emf) through L1. This results in current flowing through R1, forward biasing Q2, which becomes conductive. When the voltage across LED1 reaches the forwarding voltage of 1.7 V, the LED switches on and flashes. When the south pole moves toward the coil, the process is similar with L2, R2, Q1, and LED2 respectively. The process repeats as long as the magnet spins and the rate of change of the magnetic flux (dφ/dt) is sufficiently high.
Nikola Tesla invented and patented the Bifilar Coil on January 9, 1894
Watch other ring magnets in action:
Spinning Top Motor-Generator: youtu.be/ACyIH_tUfqM
Spinning Top Ring Magnet Energized and Released: youtu.be/5zZU-Xh3Hm4
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
Swinging Ball Magnet impulses Lego Clock Escapement: youtu.be/fVc2zLdsbqg
Torsion Pendulum Delivers Torque to Magnetic Rotors: youtu.be/ue6J2mJz3aI
Music Title: “Nightlife”
Composer and Acoustic Guitar: Michael Kobrin
Album: “Searching”, Released 2016
Mastered at Turtletone Studios, NYC, U.S.A.
A retainer plate within the spring can be turned like a nut onto bolt to change K, the spring constant.
The animation displays Simple Harmonic Motion with a frequency of 1/2π Hz on a moving time scale. First, zooming in with microsecond resolution, then, zooming out with 5-second ticks, and finally, back to microseconds.
Chapters
00:00 Side view of escapement
00:21 Escapement oscillating at 1.08 Hz
00:57 Animation of Simple Harmonic Motion
01:25 Anatomy of adjustable tension spring
01:35 Adjusting spring constant
01:47 Measuring spring displacement under load
02:21 Calculating spring constant
02:36 Escapement oscillating at 1.2 Hz
Watch other clock escapements regulated by springs:
Lego Dual Balance-Wheel Verge Escapement: youtu.be/1Exc4CGC94k
Lego Verge Escapement: youtu.be/VD6tZY34Ftc
Lego Torsion Spring Pendulum Clock Escapement: youtu.be/DmwF_GANsmE
Lego Electrostatic Torsion Pendulum Clock Escapement: youtu.be/yL8SlcBac5s
Music
Title: “Nightlife”,
Composer and Acoustic Guitar: Michael Kobrin
Album: “Searching”, Released 2016
Mastered at Turtletone Studios, NYC, U.S.A.
Two pendulums with a weak degree of coupling produce two eigenfrequencies, which in turn lead to a complex motion that is not a simple sinusoid. But the motion can be analyzed as a sum of two sinusoidal motions, each of which obeys the simple equations of Simple Harmonic Motion, and oscillates at its eigenfrequency.
The beat period depends on distance between repelling magnets. When the distance is decreased by about 8%, or 0.5 centimeter, the beat period is reduced nearly by half.
A few years ago, when I got started with Lego, I learned from YouTube contributor ‘Kevronista’ about low-friction knife-edge pivots, similar to the ones used in this video.
Chapters
00:00 Preview
00:21 In-Phase Oscillations
00:51 In-Phase Model
01:05 Out-of-Phase Oscillations
01:31 Out-of-Phase Model
01:46 Beat-Mode Oscillations — 10 Sec. Beat Period
02:40 Animation
03:12 Beat-Mode Model — 10 Sec. Beat Period
03:26 Beat-Mode Oscillations — 6 Sec. Beat Period
04:01 Beat-Mode Model — 6 Sec. Beat Period
Watch other coupled pendulums in action:
Rott’s Chaotic Pendulum: youtu.be/roJDKBClVvc
Chaotic Motion with Two Coupled Pendulums in Resonance: youtu.be/lZprTo_qK60
Double Pendulum Chaotic Gymnastics: youtu.be/EjNAyOFcwoc
Double Pendulum Chaotic Acrobatics: youtu.be/TG3ySpDxGNs
Triple Pendulum Chaotic Acrobatics: youtube.com/watch?v=d2E5oojoXjk&t=75s
Strongly coupled pendulums:
Coupled button spinner with force of gravity: youtu.be/JAq_OU7WOVw
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
Music
Title: When Sunny Gets Blue
Artist: McCoy Tyner, McCoy Tyner Trio
Album: When Sunny Gets Blue, Released 1963, UMG Recordings, Inc.
A wristwatch is subject to continuous change in position, resulting in slight and uneven contractions during rotation, shifting its own center of gravity.
A second hairspring, mounted oppositely on the same verge, averages out the sideways force. A second balance wheel anchors the spring as well as increases rotational inertia for a more consistent rate.
Abraham-Louis Breguet (1747-1823), the leading French horologist of his time, invented the "overcoil" to immune the escapement from errors caused by the changing position of the watch while being carried. Today, Audemars Piguet watch manufacturer mitigates positional error with double-stack balance-wheel and spring assembly.
According to Quill & Pad Magazine (May 29, 2016), which covers the fine watch industry:
“How does a double spiral system resist gravitational forces? Positioned opposite each other, the springs “breathe” alternately; when one expands, the other contracts. In addition, they each move in the opposite direction. So, when the center of gravity of the first balance spring makes a shift, the center of gravity of the second one moves in the exact opposite direction, thus compensating for the error and ensuring that the gravity center is always kept at the center of the balance wheel.”
Torsional constant of the 3D-printed balance spring: K = 4.65*10^-6 Newton*meter
Chapters
00:15 Positional Error in Mechanical Wristwatches
00:40 Mitigating Positional Error
01:10 Wheel assembly — Audemars Piguet Proof of Concept
01:20 Lego verge escapement — front view, 4X Actual Frequency
01:45 Lego verge escapement — top view, 4X Actual Frequency
02:12 Lego verge escapement — Actual Frequency of Oscillation
Watch other Lego verge and foliot clock escapements in action:
Lego Dual Balance-Wheel Verge Escapement: youtu.be/1Exc4CGC94k
Lego Verge Escapement: youtu.be/VD6tZY34Ftc
Lego Clock Escapement — Verge and Foliot: youtu.be/dw7g7pj5CEM
Lego Verge and Foliot Clock Escapement Transformer: youtu.be/u4EEawGgfss
Lego Verge and Pendulum Clock Escapement: youtu.be/F-wr9vcvJrg
Lego Verge and Pendulum Escapement. youtu.be/cHn_T_tGu9o
Lego Verge and Foliot vs. Verge and Pendulum Escapement: youtu.be/UbVOHz7hV9s
Erector Set Clock Escapement — Verge and Foliot: youtu.be/HOFjR_ZLtGw
Music
Title: Anomalous Hedges
Artist: Mini Vandals
Album: Anomalous Hedges, Released 2021
A hairspring in watches is pinned at the center of the spiral, and at the outer extreme. Because of the two immovable end points, it doesn’t breathe concentrically. Some watch manufacturers have corrected this problem by mounting two hairsprings, each mirroring the other and averaging out any errors.
In addition to the advantage of having twin hairsprings, two balance wheels means the inertia of the regulator is doubled, which promises more stable timekeeping since a body with greater inertia is more likely to keep going, regardless of shocks to the watch. But there is a downside, as extra energy required to move the second balance wheel.
If you follow the steps described in the brief tutorial, on making your own hairspring, you might fail to produce a decent spring in first trial. No problem — Acrylic is thermoplastic and is capable of being repeatedly softened by heating and hardened by cooling. You can immerse a deformed spring in boiling water, take it out, straighten it and repeat the steps.
Torsional constant of the 3D-printed balance spring: K = 4.65*10^-6 Newton*meter
Chapters
00:14 Dual Balance Wheel: 3D-Printed Hairsprings — Top View
00:47 Dual Balance Wheel: 3D-Printed Hairsprings — Front View
01:25 Dual Balance Wheel: 3D-Printed Hairsprings — Side View
02:15 Dual Balance Wheel: One Home-Made Hairsprings and the Other, 3D-Printed — Top View
03:03 Brief Tutorial on Making a Hairspring
Watch other Lego verge and foliot clock escapements in action:
Lego Double-Stack Balance-Wheel Verge Escapement: youtu.be/YEimiu7mLaI
Lego Verge Escapement: youtu.be/VD6tZY34Ftc
Lego Clock Escapement — Verge and Foliot: youtu.be/dw7g7pj5CEM
Lego Verge and Foliot Clock Escapement Transformer: youtu.be/u4EEawGgfss
Lego Verge and Pendulum Clock Escapement: youtu.be/F-wr9vcvJrg
Lego Verge and Pendulum Escapement. youtu.be/cHn_T_tGu9o
Lego Verge and Foliot vs. Verge and Pendulum Escapement: youtu.be/UbVOHz7hV9s
Erector Set Clock Escapement — Verge and Foliot: youtu.be/HOFjR_ZLtGw
My sincere thanks to David Ziemkiewicz for the following tips:
”For those without 3-D printer, a strip of acrylic heat-formed into a spiral (put it in boiling water, wind it over something round and let it cool in this shape) works as a decent balance spring too.”
“in my tests, 3mm wide, 1 mm thick acrylic coiled into cylindrical spring with about 2 cm diameter worked well.”
Chapters
00:15 Balance wheel runs as inertial oscillator
01:00 Magnetic repulsion with varying driving weights
03:33 Harmonic oscillations with balance spring
04:30 Top view of balance spring
Notice the pronounce recoil, of nearly 60 degrees, produced by the balance-wheel rotational inertia. Most of the wheel’s mass is distributed along its perimeter, far from the axis of rotation, making it difficult to halt and reverse the rotation.
In the magnetic repulsion mode, the recoil is barely perceptible. When one arm of the blue pallet fork releases an escape- wheel tooth, magnetic repulsion counteracts the rotational-inertia torque and reverses direction of the balance-wheel rotation (Newton’s third law of motion).
Finally, the escapement is regulated by a balance spring (AKA hairspring) — a spiral torsion spring. After the escapement reaches steady state, the top view of the balance wheel reveals a recoil of nearly 60 degrees.
Torsional constant of the 3D-printed balance spring: K = 4.65*10^-6 Newton*meter
Watch other escapements with magnetic repulsion in action:
Lego Clock Escapement w/ Magnetic Balance Wheel: youtu.be/vwsPoX16aMU
Lego Clock Escapement/Electrostatic Motor w/ Magnetic Rebound: youtu.be/cXTc3Yaby-M
Lego Verge and Pendulum Escapement: youtu.be/cHn_T_tGu9o
Lego Double-Wheel Clock Escapement with Magnetic Balance Wheel:
youtu.be/WvKwJe7b3oc
Also, watch other Lego verge and foliot clock escapements in action:
Lego Dual Balance-Wheel Escapement: youtu.be/1Exc4CGC94k
Lego Clock Escapement — Verge and Foliot: youtu.be/dw7g7pj5CEM
Lego Verge and Foliot Clock Escapement Transformer: youtu.be/u4EEawGgfss
Lego Verge and Pendulum Clock Escapement: youtu.be/F-wr9vcvJrg
Lego Verge and Foliot vs. Verge and Pendulum Escapement: youtu.be/UbVOHz7hV9s
Erector Set Clock Escapement — Verge and Foliot: youtu.be/HOFjR_ZLtGw
Lego Double-Stack Balance-Wheel Verge Escapement: youtu.be/YEimiu7mLaI
Music in this video: Piano Sonata No. 14 in C Sharp Minor, Op. 27 No. 2 "Moonlight"
Composer: Ludwig van Beethoven
From the Complete Beethoven Piano Sonatas Nos. 1-32 cycle recorded 1983-84
Artist: Daniel Barenboim
When the frequency of the entire pendulum system is one half of the red pendulum, the two pendulums draw energy from each other at a slow periodic rate. The exchange of energy period contains many pendulum-oscillation periods and this motion reproduces itself with great accuracy.
When one pendulum oscillates with maximum amplitude, the other stands almost still and the process reverses itself as the energy passes from one pendulum to the other. This process, which is associated with low energy and small amplitudes, is linear, including the coupling effect.
At very large amplitude oscillations, especially when the pendulums have enough energy to overturn (high-energy initial conditions), the behavior becomes chaotic. Chaotic or unpredictable behavior is usually associated with sensitivity to the initial data. Chaotic behavior implies that two slightly different initial conditions give rise to solution that differ greatly, one of the defining features of chaotic dynamical systems.
Chapters
00:15 Anatomy of Rott’s Pendulum
00:35 Rott’s Pendulum – Regular Motion
01:23 Rott’s Pendulum – Chaotic Motion, clockwise
02:30 Last gasp: red pendulum overturns 11 consecutive times
03:57 Rott’s Pendulum – Chaotic Motion, counterclockwise
Check out uncoupled Wave Pendulum which glows in the dark: youtu.be/3sKyTimnGHc
Watch other chaotic pendulums in action at:
Triple Pendulum Chaotic Acrobatics: youtu.be/J85gpcjvqzs
Double Pendulum Chaotic Gymnastics: youtu.be/EjNAyOFcwoc
Double Pendulum Displays Chaotic Motion: youtu.be/AwT0k09w-jw
Double Pendulum Chaotic Acrobatics: youtu.be/TG3ySpDxGNs
Chaotic Motion with Two Coupled Pendulums in Resonance: youtu.be/lZprTo_qK60
Watch other coupled pendulums exchanging energy:
Lego Coupled Pendulums with Magnets: youtu.be/b6Mmj21Rpn4
Electrostatic Coupled Oscillator with Door Chimes: youtu.be/RkG3bql3Hjw
Music
Title: Down The Street Blues
Artist: Unicorn Heads
Album: River Radio, Released 2018
When displacements from equilibrium are small, the pendulum executes simple harmonic motion (normal mode). However, when large displacements are imposed, the non-linear system becomes dramatically chaotic in its motion and demonstrates that deterministic systems are not necessarily predictable.
Chapters:
00:13 Steady State, Quasi-Harmonic Oscillations – Small Torque Applied
00:22 Chaotic motion – Torque Applied by Force of Gravity
00:52 Fleeting Moment of Hesitation
01:06 Steady State – Quasi-Harmonic Oscillations
01:18 Chaotic motion – Torque Applied by Force of Gravity
02:08 Steady State – Quasi-Harmonic Oscillations
Forces that affect the pendulum include the manual torque applied to activate the pendulum, gravitational force, and centrifugal force.
The word "chaos" is confusing, if one interprets it in the nontechnical sense of common language - "lack of order".
In fact, deterministic chaotic systems such as this pendulum, are quite ordered and theoretically predictable.
If we knew the initial state of a chaotic system in perfect detail, measured all parameters of the surrounding medium continuously, applied these data to a mathematical model on a computer, we would still be constrained the speed of calculations. Even if we deployed a quantum computer that could solve non-linear differential equations exactly, the computation would still lag behind the changing parameters by some infinitesimal unit of time.
One of the first scientists to comment on chaos was Henri Poincaré, a late-nineteenth-century French mathematician who extensively studied topology and dynamic systems. Poincaré explained, “It may happen that a small difference in the initial conditions produce very great ones in the final phenomena. A small error in the former will produce an enormous error in the latter. Prediction becomes impossible.” Dr. Nicolas Rott, of the Swiss Federal Institute of Technology in Zurich, was the first to utilize chaotic pendulums. He carried out research and analysis on pendulums as a means of demonstrating the principles of chaos and in 1970 published his findings in a document titled “A Multiple Pendulum for the Demonstration of Non-Linear Coupling.”
Check out uncoupled Wave Pendulum which glows in the dark: youtu.be/3sKyTimnGHc
Watch other chaotic and coupled pendulums in action at:
Lego Coupled Pendulums with Magnets: youtu.be/b6Mmj21Rpn4
Triple Pendulum Chaotic Acrobatics: youtu.be/J85gpcjvqzs
Rott’s Chaotic Pendulum: youtu.be/roJDKBClVvc
Double Pendulum Displays Chaotic Motion: youtu.be/AwT0k09w-jw
Chaotic Motion with Two Coupled Pendulums in Resonance: youtu.be/lZprTo_qK60
Double Pendulum Chaotic Acrobatics: youtu.be/TG3ySpDxGNs
Music: Take Five
Composer: Paul Desmond
Artists: Dave Brubeck Quartet
Dave Brubeck – piano
Paul Desmond – alto saxophone
Gene Wright – upright bass
Joe Morello – drums
Label: Columbia
Released: 1959
When displacements from equilibrium are small, the pendulum executes simple harmonic motion (normal mode). However, when large displacements are imposed, the non-linear system becomes dramatically chaotic in its motion and demonstrates that deterministic systems are not necessarily predictable.
Chapters:
00:08 Single pendulum system, normal mode with frequency of 0.8 Hz
00:39 Coupled pendulum exchanging energy at approximately 0.6 Hz
00:54 Double pendulum with counterweight, normal mode at 0.5 Hz
01:36 Larger amplitude
01:57 Chaotic motion with light torque applied
02:24 Chaotic motion with moderate torque
03:16 Chaotic motion with greater torque
"The extreme sensitivity of future behavior to small differences at early times is a characteristic of chaotic systems. This extreme sensitivity also affects predictions. Even if the theoretical model is perfect in every detail, the future behavior of a chaotic system is unpredictable because the starting conditions for the model can never be 100% accurate.
For example, the chaotic nature of weather makes accurate long-term forecast impossible. To predict the future weather, the current conditions are used as input. Any small difference between the true current conditions and those used as input will grow to huge errors in the forecast later on." University of Florida, Department of Physics.
Check out uncoupled Wave Pendulum which glows in the dark: youtu.be/3sKyTimnGHc
Watch other chaotic and coupled pendulums in action at:
Lego Coupled Pendulums with Magnets: youtu.be/b6Mmj21Rpn4
Triple Pendulum Chaotic Acrobatics: youtu.be/J85gpcjvqzs
Double Pendulum Displays Chaotic Motion: youtu.be/AwT0k09w-jw
Double Pendulum Chaotic Gymnastics: youtu.be/EjNAyOFcwoc
Rott’s Chaotic Pendulum: youtu.be/roJDKBClVvc
Chaotic Motion with Two Coupled Pendulums in Resonance: youtu.be/lZprTo_qK60
Music
Title: By the Fireplace
Artist: TrackTribe
Album: By the Fireplace, Released 2020
High-voltage electric field polarizes steel balls which form chains, or shooters. This phenomenon is analogous to the familiar buckyballs magnets which are magnetically polarized and will form a chain if positioned in close proximity to each other.
The apparatus consists of a high-voltage power supply, Petri dish with tiny steel balls in a substrate of castor oil, a dielectric which introduces drag. Above the dish is a pointed copper-wire electrode connected to the positive terminal of the power supply. Aluminum foil coats the inner perimeter wall of the dish and is connected to electrical ground.
Corona discharge, accompanied by hissing sound, occurs in air near the copper-wire electrode where neutral atoms and molecules become positively charged ions, or cations. An electric field is formed between the positive electrode and negatively charged steel balls near the perimeter of the dish. The balls are attracted to the center of the dish as they form chains which reorganize themselves, following the path of least resistance. Oh yes, there is also the sweet smell of Ozone in the air.
Watch another experiment that runs on high voltage with larger metallic balls at: youtu.be/EVUhawSk7_4
The experiment with Petri dish is based on a research project at the Physics Department, University of Illinois.
Music: Richard Wagner, Lohengrin – Prelude, Orchester der Bayreuther Festspiele, Woldemar Nelsson
Huygens modified the verge and foliot escapement by turning it 90 degrees so that the crown wheel with sawtooth-shaped teeth faces up. He installed a pendulum which replaced the inertial oscillator, a balance wheel, or in the earliest clocks a foliot, a horizontal rod with weights on either end.
This Lego escapement consists of an escape wheel, shaped like a crown with pins along the perimeter, perpendicular to the wheel itself that is attached to an axle. Red pallets at opposite ends of a horizontal rod, or verge, above the crown wheel, engage the pins alternately. The pallets are offset from the verge’s axis so that when one pallet engages one of the pins, the other pallet is between two pins, therefore avoiding jamming the escapement.
The two escapements have identical escape wheel and pallet fork. However, the verge and foliot is regulated by the inertia of the foliot that is prone unpredictable error, while the one regulated by a pendulum has a natural frequency of oscillation.
The foliot appears to be slowing down and speeding up unpredictably throughout the run, while the pendulum escapement appears to be oscillating steadily, as expected.
The escapement converts rotational energy of the crown wheel into oscillating movement that regulates timing. Also, the escapement restrains the motion of the falling weight where the pallets prevent the crown wheel from spinning uncontrollably in order to let the weight fall in a measured manner.
Watch other verge and foliot escapements in action:
Lego Double-Stack Balance-Wheel Verge Escapement: youtu.be/YEimiu7mLaI
Lego Dual Balance-Wheel Escapement: youtu.be/1Exc4CGC94k
Lego Verge Escapement with magnets and Balance Spring: youtu.be/VD6tZY34Ftc
Metallic verge and foliot: youtu.be/HOFjR_ZLtGw
Lego verge and foliot: youtu.be/dw7g7pj5CEM
Lego verge and foliot and pendulum escapement, side-by-side: youtu.be/UbVOHz7hV9s
Huygens modified the verge and foliot escapement by turning it 90 degrees so that the crown wheel with sawtooth-shaped teeth faces up. He installed a pendulum which replaced the inertial oscillator, a balance wheel, or in the earliest clocks a foliot, a horizontal rod with weights on either end.
This Lego escapement consists of an escape wheel, shaped like a crown with pins along the perimeter, perpendicular to the wheel itself that is attached to an axle. Yellow pallets at opposite ends of a horizontal rod, or verge, above the crown wheel, engage the pins alternately. The pallets are offset from the verge’s axis so that when one pallet engages one of the pins, the other pallet is between two pins, therefore avoiding jamming the escapement.
The escapement converts rotational energy of the crown wheel into oscillating movement that regulates timing. Also, the escapement restrains the motion of the falling weight where the pallets prevent the crown wheel from spinning uncontrollably in order to let the weight fall in a measured manner.
Watch other verge escapements in action:
Lego Double-Stack Balance-Wheel Verge Escapement: youtu.be/YEimiu7mLaI
Lego Dual Balance-Wheel Escapement: youtu.be/1Exc4CGC94k
Lego Verge Escapement: youtu.be/VD6tZY34Ftc
Lego Verge and Foliot Clock Escapement Transformer: youtu.be/u4EEawGgfss
Lego Clock Escapement — Verge and Foliot: youtu.be/dw7g7pj5CEM
Lego Verge and Pendulum Clock Escapement: youtu.be/F-wr9vcvJrg
Lego Verge and Pendulum Escapement. youtu.be/cHn_T_tGu9o
Lego Verge and Foliot vs. Verge and Pendulum Escapement: youtu.be/UbVOHz7hV9s
Erector Set Clock Escapement — Verge and Foliot: youtu.be/HOFjR_ZLtGw
The button spinner escapement consists of the following components:
1. 6-prong (teeth) escape wheel
2. Locking lever that rests on a pin
3. Vertical pallet that can rock back and forth
4. Arm that rests between the escape-wheel prong and pallet
5. Sewing button (1" OD) strung on a cotton sewing thread
6. Lead mass, 1.875 oz
When at rest, the escape wheel is locked by the locking lever. As the button spins, the string twists and its length is shortened, pushing the vertical pallet towards the locking lever. The pallet then lifts the locking lever and releases the escape wheel. The escape-wheel prong slides down over an arm that in turn impels the pallet away, thereby extending the length of the string. This results in a torque that produces rotation of the button. The restoring force twists the button in the opposite direction, the string length is shortened, and the cycle repeats. The escape-wheel prong impels away the vertical pallet by gradually sliding rather than applying an impulse as in swinging pendulum clocks. Gradual delivery of torque is needed in order to accommodate the moment of inertia of this torsion pendulum. A mass of almost 2 oz was needed to transfer force from the escape wheel to the pallet and convert it to torque. This borderline weight for a Lego structure is obvious when you notice how the entire frame of the escapement vibrates with each strike.
In 2017, Dr. Manu Prakash et al. at Stanford University, created the “paperfuge”, a hand-powered centrifuge, based on the buzzer whirligig that could be used in places that lack resources such as electricity. The paperfuge could separate pure plasma from whole blood for diagnosing conditions where a parasite is in the blood — such as malaria.
You can watch other button spinners and torsion pendulums in action at:
8-prong button spinner 360-degree view: youtu.be/i6sAWHaZXXI
3-Prong button Spinner with force of gravity: youtu.be/42i87nh04As
Coupled button spinner with force of gravity: youtu.be/JAq_OU7WOVw
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
Electromagnetic driver: youtu.be/Gleg2dWei8E
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
The button spinner escapement consists of the following components:
1. 8-tooth escape wheel
2. Locking lever that rests on a pin
3. Vertical pallet suspended by a string
4. Sewing button (1" OD) strung on cotton sewing thread
5. Lead mass, 1.5 oz
Static Stage: When at rest, the escape wheel is locked by the locking lever.
Impellent Stage: The escape-wheel tooth slides down and pushes a blue pin on the vertical pallet, which in turn, stretches the twisted string. This results in torque that rotates the button in one direction. During this stage, energy is delivered and stored in the string.
Unlocking Stage: Energy is released and the restoring torque rotates the button in the opposite direction. The yellow right-angle piece that is mounted on the pallet lifts the locking lever, thus releasing the escape wheel. If that yellow piece were missing, the blue pin would engage the escape-wheel tooth, resulting in recoil and oscillations would stop.
The escape-wheel tooth impels the vertical pallet by gradually sliding rather than applying an impulse as in traditional swinging-pendulum clocks. Gradual delivery of torque is needed in order to accommodate the moment of inertia of this torsion pendulum. A mass of 1.5 oz was needed to run the escapement.
The 1” button must be of minimum weight for developing minimum angular momentum, which in turn, would allow sufficient energy to be stored in the string during the impellent phase. The button weight in this escapement was 0.13 oz. This escapement would not run with a 1” plastic button weighing 0.08 oz.
In 2017, Dr. Manu Prakash et al. at Stanford University, created the “paperfuge”, a hand-powered centrifuge, based on the buzzer whirligig that could be used in places that lack resources such as electricity. The paperfuge could separate pure plasma from whole blood for diagnosing conditions where a parasite is in the blood — such as malaria.
You can watch other button spinners and torsion pendulums in action at:
6-Prong button spinner with force of gravity 360-Degree View: youtu.be/4XoJ646-JEE
3-Prong button spinner with force of gravity: youtu.be/42i87nh04As
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
Coupled button spinner: youtu.be/JAq_OU7WOVw
Electromagnetic driver: youtu.be/Gleg2dWei8E
Electrostatic induction-motor driver: youtu.be/yL8SlcBac5s
The escapement consists of the following components:
1. 6-prong (teeth) escape wheel
2. Locking lever that rests on a pin
3. Vertical pallet that can rock back and forth
4. Arm that rests between the escape-wheel prong and pallet
5. 2 Sewing buttons (1" OD) strung on a polyester sewing thread
6. Lead mass, 1.875 oz
When at rest, the escape wheel is locked by the locking lever. As one button spins in one direction, the second spins in the opposite direction, the string twists and its length is shortened, pushing the vertical pallet towards the locking lever. The pallet then lifts the locking lever and releases the escape wheel. The escape-wheel prong slides down over an arm that in turn impels the pallet away, thereby extending the length of the string. This results in a torque that produces rotation of the two buttons. The restoring force twists each button in the opposite direction, the string length is shortened, and the cycle repeats.
The escape-wheel prong impels away the vertical pallet by gradually sliding rather than applying an impulse as in swinging pendulum clocks. Gradual delivery of torque is needed in order to accommodate the moment of inertia of this torsion pendulum. A mass of almost 2 oz was needed to transfer force from the escape wheel to the pallet and convert it to torque. This borderline weight for a Lego structure is obvious when you notice how the entire frame of the escapement is shaken with each strike. A more vigorous shake of a button spinner with 3-prong escape wheel can be viewed at youtu.be/42i87nh04As
In 2017, Dr. Manu Prakash et al. at Stanford University, created the “paperfuge”, a hand-powered centrifuge, based on the buzzer whirligig that could be used in places that lack resources such as electricity. The paperfuge could separate pure plasma from whole blood for diagnosing conditions where a parasite is in the blood — such as malaria.
Check out uncoupled Wave Pendulum which glows in the dark: youtu.be/3sKyTimnGHc
You can watch other button spinners and torsion pendulums in action at:
8-prong button spinner with force of gravity 360-degree view (#1): youtu.be/i6sAWHaZXXI
6-Prong button spinner with force of gravity 360-Degree View (#2): youtu.be/4XoJ646-JEE
3-Prong button spinner with force of gravity (#3): youtu.be/42i87nh04As
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
Electromagnetic driver: youtu.be/Gleg2dWei8E
Electrostatic induction-motor driver: youtu.be/yL8SlcBac5s
The button spinner escapement consists of the following components:
1. 3-prong (teeth) escape wheel
2. Locking lever that rests on a pin
3. Vertical pallet that can rock back and forth
4. Arm that rests between the escape-wheel prong and pallet
5. Sewing button (1" OD) strung on a cotton sewing thread
6. Lead mass, 1.875 oz
When at rest, the escape wheel is locked by the locking lever. As the button spins, the string twists and its length is shortened, pushing the vertical pallet towards the locking lever. The pallet then lifts the locking lever and releases the escape wheel. The escape-wheel prong slides down over an arm that in turn impels the pallet away, thereby extending the length of the string. This results in a torque that produces rotation of the button. The restoring force twists the button in the opposite direction, the string length is shortened, and the cycle repeats.
The escape-wheel prong impels away the vertical pallet by gradually sliding rather than applying an impulse as in swinging pendulum clocks. Gradual delivery of torque is needed in order to accommodate the moment of inertia of this torsion pendulum. A mass of almost 2 oz was needed to transfer force from the escape wheel to the pallet and convert it to torque. This borderline weight for a Lego structure is obvious when you notice how the entire frame of the escapement vibrates each strike.
In 2017, Dr. Manu Prakash et al. at Stanford University, created the “paperfuge”, a hand-powered centrifuge, based on the buzzer whirligig that could be used in places that lack resources such as electricity. The paperfuge could separate pure plasma from whole blood for diagnosing conditions where a parasite is in the blood — such as malaria.
You can watch other button spinners and torsion pendulums in action at:
8-prong button spinner 360-degree view: youtu.be/i6sAWHaZXXI
6-Prong button Spinner with force of gravity 360-Degree View: youtu.be/4XoJ646-JEE
Coupled button spinner with force of gravity: youtu.be/JAq_OU7WOVw
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
Electromagnetic driver: youtu.be/Gleg2dWei8E
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
Timestamps:
00:07 Top spun manually, power turned on
01:32 Spinning stabilized, power turned off
02:24 Precession begins
03:31 Spinning stabilized again, top appears motionless
03:35 Precession, slowing down
04:48 Ouch! Collapse
What allows the top to spin for over 3 minutes without being driven?
1. Low center of gravity
2. Low friction at the base with well-polished tip and smooth mirror surface
3. Reaching stable upright spinning (gyroscopic effect) prior to turning off power
During precession, the top spins slowly around a vertical axis through its point of support while it spins rapidly about its own axis.
The top was clocked at 1200 RPM, with a stroboscope, just before power was turned off.
Materials
Top: 2-pole diametrically-polarized neodymium ring magnet
Axle: Knitting needle
Electronic circuit: Bistable multivibrator with air-core bifilar coil, hand-wound with magnet wire
A description of circuit operation is found at:
youtu.be/tLtNEmAfQpM
Nikola Tesla invented and patented the Bifilar Coil on January 9, 1894
Watch other ring magnets in action at:
Lego Wind Turbine Generates Electricity: youtu.be/frzhJ6VV7i4
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
Swinging Ball Magnet Impulses Lego Clock Escapement: youtu.be/fVc2zLdsbqg
Spinning Top Motor-Generator: youtu.be/ACyIH_tUfqM
Torsion Pendulum Delivers Torque to Magnetic Rotors: youtu.be/ue6J2mJz3aI
The Pulsating Sound of Spinning-Top Magnet: youtu.be/86gle0Gt_g8
When the spiral begins to spin, the bubbles become blurry but as soon as strobe flashes illuminate it, they come into view.
The Phenakistoscope was an early animation device used to produces the optical illusion of apparent motion.
Etymology - Greek: Phenakistoscope: phenax = deceptive, scopio = to look at.
The Phenakistoscope was invented by Belgian Joseph Plateau in 1841. The illusion is due to persistence of vision (Phi phenomenon) in which humans perceive the decay of a visual stimulus, slower than the actual decay.
The motor is mounted on Meccano/Erector-Set frame and its rotation rate is controlled with a rheostat which limits electrical current. The flashes are produced by a xenon lamp stroboscope.
Timestamps:
00:10 Strobe flashes begin
00:34 Strobe flashes stop
00:41 Strobe flashes begin again
00:55 Rotation of motor begins to increases from 48 to 60 RPM
01:12 View of paper-towel dispenser motor and rheostat
Strobe flashing rate (Flashes Per Minute) was calculated as follows:
approximate number of contiguous bubbles along diameter of circle * 48 RPM = 35 * 48 = 1,680 FPM
The bubbles come into view with the strobe flashing at 1,680 frames/min or 28 flashes/sec.
Low frequency background flashing results from the difference between strobe flashing rate and video camera frame rate:
28 strobe flashes/sec – 24 camera frames/sec = 4 flashes/second
Watch other strobe-activated displays in action at:
Motorized Phenakistoscope vs. Digitized Phenakistoscope: ://youtu.be/iSmGYz2fFb4
Lego Zoetrope with Electrostatic Motor: youtu.be/yAucTUs9x9g
Lego Phenakistoscope Run by Electrostatic Motor: youtu.be/MjuReCiZBbI
The frequency of oscillation is determined by the natural frequency of the springs and inertia of the balance bar and anchor.
Each galvanized steel spring measures 2.54 cm in diameter with a length of
3 cm when relaxed. The length of each spring is 25 cm at rest, in a vertical position, and fully extended by its own weight of 26 g. The escapement weight is made of two lead fishing-egg-sinkers weighing a total of 28 g.
Handling these spring feels like holding live snakes, they seem to have a life of their own.
You can watch another escapement regulated by springs at: youtu.be/NVqK2_j_j_Q
Each galvanized steel spring measures 2.54 cm in diameter with a length of 3 cm when relaxed. The length of each spring is 25 cm at rest, in a vertical position, and fully extended by its own weight of 26 g. The escapement weight is made of two lead fishing-egg-sinkers weighing a total of 28 g.
Handling these spring feels like holding live snakes, they seem to have a life of their own.
You can watch another escapement regulated by springs at: youtu.be/4uXJq9ZGnbM
Both the entry pallet (yellow) and exit pallet (red) in this Lego model have a sloping impulse face.
Although the escape wheel does not recoil, this Lego version does not represent a true deadbeat escapement. Here, the entry and exit pallets neither have a ‘locking’ nor ‘dead’ face nor a sloping impulse face.
The silver balls are chrome-coated plastic beads.
While the frequency of the Schatz clock is 8 beats per minute, this Lego version produces about 14 beats per minute.
This Lego version of Galileo's escapement consists of a pinwheel and "L"-shape component that forms a pair of pawls. When at rest, the escape wheel is locked by the short pawl. In motion, the red pin at the edge of the pendulum strikes the long pawl, unlocks the escape wheel, which in turn rotates, and strikes the long pawl, which impulses the pendulum.
The torsion spring stores mechanical energy when it is twisted along its axis. The spring exerts torque in the opposite direction, proportional to the angle of deflection from rest position.
The frequency of oscillation can be controlled by moving the silver balls in or out from the axis. The closer the balls are, the smaller the moment of inertia of the torsion pendulum and the faster it will run, like an ice skater who pulls in his or her arms.
Watch other torsion pendulum escapements in action at:
8-prong button spinner with force of gravity: youtu.be/i6sAWHaZXXI
6-Prong button spinner with force of gravity: youtu.be/4XoJ646-JEE
3-Prong button spinner with force of gravity: youtu.be/42i87nh04As
Coupled button spinner: youtu.be/JAq_OU7WOVw
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
Electromagnetic driver: youtu.be/Gleg2dWei8E
The impulse is applied by nearly half-round pins standing out from the face of the escape wheel. When one pin lets off the exit pallet, the bottom of the oncoming pin locks on the entry pallet.
The pinwheel escapement, a useful form of the deadbeat escapement, has a few advantages: if a pin gets broken it is easily replaced, whereas is in the other the wheel is ruined if a tooth is damaged; a wheel of given size will work with more pins than teeth and therefore a train of less velocity will do and that sometimes amounts to a savings of one wheel in the train and a good deal of friction; and with the blow on both pallets being downwards instead of one up and the other down, the action is more steady; finally, the wearing out of the pallet-staff hole would not affect the amount of impulse - all which things are of more consequence in the heavy and rough work of a turret clock than in an astronomical one.
You can watch another pinwheel escapement in action at: youtu.be/FUTE5Ab1v6s
Reference: The Encyclopedia Britannica, A Dictionary of Arts, Sciences, And General Literature, Volume VI. 1877
The impulse is applied by nearly half-round pins standing out from the face of the escape wheel. When one pin lets off the exit pallet, the bottom of the oncoming pin locks on the entry pallet.
The pinwheel escapement, a useful form of the deadbeat escapement, has a few advantages:
if a pin gets broken it is easily replaced, whereas is in the other the wheel is ruined if a tooth is damaged; a wheel of given size will work with more pins than teeth and therefore a train of less velocity will do and that sometimes amounts to a savings of one wheel in the train and a good deal of friction; and with the blow on both pallets being downwards instead of one up and the other down, the action is more steady; finally, the wearing out of the pallet-staff hole would not affect the amount of impulse - all which things are of more consequence in the heavy and rough work of a turret clock than in an astronomical one.
Watch a pinwheel escapement with 12 pins in action at: youtu.be/rnyemq53GSU
Reference: The Encyclopedia Britannica, A Dictionary of Arts, Sciences, And General Literature, Volume VI. 1877
Timestamps:
00:04 Harmonic Motion Stage 1
00:18 Harmonic Motion Stage 2
00:33 Harmonic Motion Stage 3
00:55 Chaotic Motion Stage 1
01:39 Chaotic Motion Stage 2
02:40 Chaotic Motion Stage 3
"The extreme sensitivity of future behavior to small differences at early times is a characteristic of chaotic systems. This extreme sensitivity also affects predictions. Even if the theoretical model is perfect in every detail, the future behavior of a chaotic system is unpredictable because the starting conditions for the model can never be 100% accurate.
For example, the chaotic nature of weather makes accurate long-term forecast impossible. To predict the future weather, the current conditions are used as input. Any small difference between the true current conditions and those used as input will grow to huge errors in the forecast later on." University of Florida, Department of Physics, demo of Chaotic Pendulum.
Check out uncoupled Wave Pendulum which glows in the dark: youtu.be/3sKyTimnGHc
Watch other chaotic and coupled pendulums in action at:
Lego Coupled Pendulums with Magnets: youtu.be/b6Mmj21Rpn4
Double Pendulum Displays Chaotic Motion: youtu.be/AwT0k09w-jw
Double Pendulum Chaotic Gymnastics: youtu.be/EjNAyOFcwoc
Rott’s Chaotic Pendulum: youtu.be/roJDKBClVvc
Double Pendulum Chaotic Acrobatics: youtu.be/TG3ySpDxGNs
Chaotic Motion with Two Coupled Pendulums in Resonance: youtu.be/lZprTo_qK60
Reference: Make magazine Volume 22, June 2010.
Magnets on each side, face each other with the same polarity.
The pendulums are shown moving in three modes:
Timestamps:
00:01 Beat Frequency Point: One pendulum is at rest while the other is at maximum amplitude
00:32 In-Phase: Both pendulums move in the same direction
00:46 Out-of-Phase: The pendulums move in opposite directions
00:59 Again, Beat Frequency Point
Lastly, the pendulums are set again in beat frequency mode where the amplitude of one increase while the amplitude of the other decreases to a stop and vice versa.
The beat frequency, or the number of cycles per minute in which the two pendulums exchange energy back and forth is the difference between the number of cycles per minute during the in-phase and out-of-phase mode. The beat frequency for these pendulums can be measured after the oscillations stabilize and it is approximately 5 cycles in one minute.
Each pendulum is pivoted on knife edge suspension which offers significantly lower friction than Lego axle-in-plain bearing.
Check out an improved version of this pendulum at: youtu.be/b6Mmj21Rpn4
Watch other coupled pendulums exchanging energy:
Rott's Chaotic Pendulum: youtu.be/roJDKBClVvc
Electrostatic Coupled Oscillator with Door Chimes: youtu.be/RkG3bql3Hjw
As soon as the bipolar neodymium ball magnet is manually released onto the arc-shaped plastic track, it begin swinging from side to side. The air-core coil is connected to an electronic switch, bistable multivibrator (hidden from view behind the coil), that maintains the magnetic field in the coil in one direction (left to right) or the other (right to left). As the ball magnet rolls along the track inside the coil, its polarity is aligned with the magnetic field and is propelled forward. During this motion it induces Counter ElectroMotive Force (CEMF) that reverses the direction of the magnetic field (Lenz's law) and the process repeats.
Watch other ring magnets in action at:
Lego Wind Turbine Generates Electricity: youtu.be/frzhJ6VV7i4
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
Spinning Top Motor-Generator: youtu.be/ACyIH_tUfqM
Torsion Pendulum Delivers Torque to Magnetic Rotors: youtu.be/ue6J2mJz3aI
The Pulsating Sound of Spinning-Top Magnet: youtu.be/86gle0Gt_g8
Spinning Top Ring Magnet Energized and Released: youtu.be/5zZU-Xh3Hm4
The electronic circuit on the back of this escapement can be viewed at:
youtu.be/tLtNEmAfQpM
YouTube fellow Ben van de Waal was kind enough to review the escapement that had been posted last week: "Lego Coupled-Torsion-Pendulums Clock Escapement"
youtu.be/tLtNEmAfQpM
and suggested connecting the escape wheel to some kind of gear train, to be able to judge precision of the escapement.
Gear Train
8-tooth pinion gear, mounted on the 8-tooth-scapewheel axle, is mated to a 24-tooth gear for rotational speed reduction of 3:1. A red pointer is mounted on the 24-tooth-gear axle as an indicator for measuring precision of the escapement.
Watch other torsion pendulum escapements in action at:
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
8-prong button spinner with force of gravity: youtu.be/i6sAWHaZXXI
6-Prong button spinner with force of gravity: youtu.be/4XoJ646-JEE
3-Prong button Spinner with force of gravity: youtu.be/42i87nh04As
Coupled button spinner with force of gravity: youtu.be/JAq_OU7WOVw
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
The upper pendulum is made of Lego while the lower is made of a diametrically-polarized neodymium ring magnet. The pendulums are suspended from a pair of 0.25-mm diameter inextensible sewing thread that is fixed at the top of the supporting frame. Tension in the thread is maintain by 6 lead egg-sinkers, threaded, and wrapped around a Lego wheel, with a combined weight of 85 grams.
The driver consists of a two-transistor Bistable Multivibrator (Flip-Flop) where the collector load of each transistor is made of half an air-core bifilar coil ("inductor"). When power is turned on, the end of the coil near the pendulum ring-magnet will have one of two states: either North magnetic polarity or South. Assume it is South. When the magnet rotates, its North pole will be attracted by the inductor. The magnet will induce Counter ElectroMotive Force (CEMF) in the inductor that will switch the Flip-Flop to the other state. The inductor will reverse polarity and repel the North pole of the ring-magnet; the magnet will continue rotating with its moment of inertia, and the process repeats.
The pendulums oscillate out of phase with each other — rotating in opposite directions. They reverse their respective direction of rotation when torsion in the string exceeds their combined moment of inertia.
Timestamp
1:15 View of the Bistable Multivibrator
This escapement is a compact version of a similar one I had posted on YouTube last month.
Watch other torsion pendulum escapements in action at:
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
8-prong button spinner with force of gravity: youtu.be/i6sAWHaZXXI
6-Prong button spinner with force of gravity: youtu.be/4XoJ646-JEE
3-Prong button Spinner with force of gravity: youtu.be/42i87nh04As
Coupled button spinner: youtu.be/JAq_OU7WOVw
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
The upper pendulum is made of Lego parts while the lower contains a diametrically-polarized neodymium ring magnet. The pendulums are suspended from a 0.25-mm diameter inextensible sewing thread that is fixed at the top of the supporting frame. Tension in the thread is maintain by four lead egg-sinkers with a combined weight of 85 grams.
The coupled pendulums oscillate out of phase (in opposite direction).
The driver consists of a two-transistor Bistable Multivibrator (Flip-Flop) where the collector load of each transistor is made of half an air-core bifilar coil ("inductor"). When power is turned on, the end of the coil near the pendulum ring-magnet will have one of two states: either North magnetic polarity or South. Assume it is South. When the magnet rotates, its North pole will be attracted by the inductor. The magnet will induce Counter ElectroMotive Force (CEMF) in the inductor that will switch the Flip-Flop to the other state. The inductor will reverse polarity and repel the North pole of the ring-magnet; the magnet will continue rotating with its moment of inertia, and the process repeats.
The pendulums reverse their respective direction of rotation when torsion in the string exceeds their moment of inertia.
Watch other torsion pendulum escapements in action at:
8-prong button spinner with force of gravity: youtu.be/i6sAWHaZXXI
6-Prong button spinner with force of gravity: youtu.be/4XoJ646-JEE
3-Prong button Spinner with force of gravity: youtu.be/42i87nh04As
Torsion spring with force of gravity: youtu.be/DmwF_GANsmE
Coupled button spinner: youtu.be/JAq_OU7WOVw
Electromagnetic motor driver: youtu.be/Gleg2dWei8E
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
The upper pendulum is made of Lego parts while the lower is made of a diametrically-polarized neodymium ring magnet. The pendulums are suspended from a 60-cm long, 0.25-mm diameter inextensible sewing thread that is fixed at the top of the supporting frame. Tension in the thread is maintain by a 170-gram weight at the bottom.
The driver of the pendulums is a Bistable Multivibrator with air- core bifilar coil load.
Watch other torsion pendulum escapements in action at:
8-prong torsion pendulum with force of gravity: youtu.be/i6sAWHaZXXI
6-Prong torsion pendulum with force of gravity: youtu.be/4XoJ646-JEE
3-Prong torsion pendulum with force of gravity: youtu.be/42i87nh04As
Torsion spring pendulum with force of gravity: youtu.be/DmwF_GANsmE
Coupled torsion pendulum: youtu.be/JAq_OU7WOVw
Electromagnetic motor driver: youtu.be/Gleg2dWei8E
Electrostatic induction motor driver: youtu.be/yL8SlcBac5s
The driver consists of a two-transistor bistable multivibrator (Flip-Flop) where the collector load of each transistor is made of half an air-core bifilar coil. When the magnet rotates, one of its pole, say N, is attracted by the inductor; the magnet induces Counter EMF in the inductor that switches the Flip-Flop to the other state. The inductor reverses polarity and repels the N pole of the top; the top continues to rotate with its moment of inertia and the process repeats.
After power is cut off, the two LEDs light up whenever the top is brought near the inductor.
Timestamps
00:07 Motor Mode
00:49 Generator Mode
Watch other ring magnets in action:
Lego Wind Turbine Generates Electricity: youtu.be/frzhJ6VV7i4
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
The Pulsating Sound of Spinning-Top Magnet: youtu.be/86gle0Gt_g8
Spinning Top Ring Magnet Energized and Released: youtu.be/5zZU-Xh3Hm4
Swinging Ball Magnet Impulses Lego Clock Escapement: youtu.be/fVc2zLdsbqg
The pendulum consists of two 3-cm OD neodymium ring magnets suspended from a 29-cm elastic band* that is free to twist about its axis. Each one of the nine rotors is made up of seven 3-mm neodymium balls, placed in a plastic cup. The cups rest on a towel which offers enough friction to prevent them from gravitating toward each other or worse yet, toward the pendulum magnets.
The driver consists of a two-transistor Bistable Multivibrator where the collector load of each transistor is made of half of an air-core bifilar coil. When the pendulum magnet rotates, one of its poles, say N, is attracted by the inductor; the magnet induces Counter EMF in the inductor that switches the flip-flop to the other state. The inductor reverses polarity and repels the N pole of the pendulum magnet which then continues to rotate with its moment of inertia and the process repeats. The pendulum reverses its direction of rotation when torsion in the elastic band exceeds the moment of inertia of the pendulum.
* Torsion pendulum can be defined as a disk suspended from a torsion wire that is essentially inextensible. The pendulum shown in this video, however, is made of an elastic band.
Watch other ring magnets in action at:
Lego Wind Turbine Generates Electricity: youtu.be/frzhJ6VV7i4
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
Spinning Top Motor-Generator: youtu.be/ACyIH_tUfqM
The Pulsating Sound of Spinning-Top Magnet: youtu.be/86gle0Gt_g8
Spinning Top Ring Magnet Energized and Released: youtu.be/5zZU-Xh3Hm4
Swinging Ball Magnet Impulses Lego Clock Escapement: youtu.be/fVc2zLdsbqg
Sonification of an oscillating magnetic field.
Hall-effect sensor IC at the edge of the magnifying mirror produces voltage proportional to the magnetic flux density which is a function of motion, position, and changes in magnetic field strength. The output of the sensor IC is connected to a Theremin whose variable RF oscillator was modified to run as a Voltage Controlled Oscillator.
Timestamps:
00:51 Top collapses
01:07 Tweeting
01:41 Wha-Wha
01:51 Alien spacecraft sound effect
Watch other ring magnets in action at:
Lego Coupled Torsion Pendulums Clock Escapement: youtu.be/Gleg2dWei8E
Spinning Top Motor-Generator: youtu.be/ACyIH_tUfqM
Torsion Pendulum Delivers Torque to Magnetic Rotors: youtu.be/ue6J2mJz3aI
Spinning Top Ring Magnet Energized and Released: youtu.be/5zZU-Xh3Hm4
Swinging Ball Magnet Impulses Lego Clock Escapement: youtu.be/fVc2zLdsbqg
The nearly linear side-to-side motion of the rack bar is converted into rotational motion (rotary actuator) of an 8-tooth circular gear on a brass axle of the balance wheel. The brass axle slides over smooth bearing of Lego brick holes rendering more uniform and lower friction than with Lego Technic axle with its length-wise ridges.
As the escape wheel turns, one spoke at a time, a small neodymium magnet at top of the balance wheel oscillates between two stationary magnets. The stationary magnets are mounted on a swivel which is concentric with the balance wheel, and was adjusted for somewhat uniform oscillation.
A brass axle of the balance-wheel slides over smooth bearing of Lego brick holes. This combination results in more uniform and lower friction than with Lego Technic axle with its length-wise ridges.
The escapement was adjusted to match the resonance frequency of the balance-wheel.
A neodymium magnet attached at top of the oscillating balance wheel is flanked by two stationary magnets. The stationary magnets are mounted on a swivel which is concentric with the balance wheel, allowing fine tuning the point at which impulse is transferred to the pallet. Ben van de Waal had kindly suggested this swivel mount for an earlier escapement with magnetic balance wheel.
The stationary magnets are mounted on a swivel which is concentric with the balance wheel. This swivel allows fine tuning the point at which impulse is transferred to the pallet.
My sincere appreciation again, to Ben van de Waal for analyzing previous versions of the escapement and suggesting a swivel mount and how to adjust the escapement for harmonic oscillations.
The positions of the stationary magnets were selected so that the magnet on the balance wheel is equidistant from them by magnetic repulsion. This point of equilibrium can be seen in the video when the escapement is at rest and the balance wheel is manually freed from the red L-shaped anchor. At equilibrium magnet on the wheel is at 1 o'clock.
I owe Ben van de Waal a debt of gratitude for reviewing an earlier version of the escapement, pointing out the correct timing, as well as making suggestions on adjusting it.
The balance wheel is detached from the rest of the escapement , except at the midpoint of its swing when it strikes the exit pallet and receives an impulse.
When at rest, the escape wheel is locked by the weighted entry pallet (weight behind supporting structure). Once the balance wheel is set in motion, clockwise, its extended yellow-and-blue L-shaped arm strikes the exit pallet.
At that point, the entry pallet releases the escape wheel whose spoke slides up the entry pallet which in turn, imparts an impulse to the balance wheel.
The impulse reverses the direction of rotation of the balance wheel until magnets on its spokes collide elastically with stationary magnets (repulsion of same polarity) mounted on each side of the frame. The cycle is repeated until the weight lands on the floor...
The tumbling acrobat was popular in China in the nineteen century and was introduced into Europe. In the late nineteen century, the tumbling toy was made in the German village of Seiffen (Erzgebirge region) which had become the center of a wooden toy industry.
Watch other walkers in action:
Jansen Walker and Lego Walker Keep on Marching: youtu.be/pqepnF5tSUo
Lego Passive Dynamic Walker: youtu.be/j1BZ128YU9I
Lego Tumbling Automaton: youtu.be/VXvezNiOlGc
Also, watch other walkers in action
Jansen Walker and Lego Walker: youtu.be/mP6iDxHEmUI
Lego Tumbling Acrobat Automaton: youtu.be/KELP9SjrSn0
Lego Passive Dynamic Walker: youtu.be/j1BZ128YU9I


