Ami VarsanoWatch the magic of light chasers. This video showcases various geometric shapes of light chasers (marquees) in action.
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
Marquee Light Chaser CollectionAmi Varsano2023-07-16 | Watch the magic of light chasers. This video showcases various geometric shapes of light chasers (marquees) in action.
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
Music Title: Down The Street Blues Artist: Unicorn Heads Album: River Radio, Released 2018Motorized Phenakistoscope vs. Digitized PhenakistoscopeAmi Varsano2023-11-04 | The phenakistoscope, invented in 1832 was the first widespread animation device that created a fluent illusion of motion. The device consisted of a cardboard disc that contained images and a viewing slit between each pair of images. When the disc was spun, the viewer could see the moving images reflected in a mirror.
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, 1985Jansen Walker and Lego Walker Keep on MarchingAmi Varsano2023-10-21 | This walker is animated as an ‘inline biped’ as well as a quadruped, with one set of legs moving out of phase with the other half. The ‘creature’ is walking in place while the ground is moving backward, giving the impression that the walker is moving forward.
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/VXvezNiOlGcOptimizing Basketball Shots with Monte Carlo SimulationAmi Varsano2023-09-02 | This video shows how to use Monte Carlo simulation to analyze, optimize, and forecast the success rate of basketball shots. The goal is to find the optimal combination of launch angles and speeds that result in the highest success rate.
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, 2018Wave Pendulum CollectionAmi Varsano2023-06-17 | Animation of combined wave pendulums displays geometric configurations which are not necessarily intuitively predictable.
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, PianoWave Pendulum AnimationAmi Varsano2023-06-10 | This animation displays a sequence of visual wave patterns, including transverse traveling wave, standing wave, and beat mode.
Music Title: “Nightlife” Composer and Acoustic Guitar: Michael Kobrin Album: “Searching”, Released 2016 Mastered at Turtletone Studios, NYC, U.S.A.Lego Undamped Wave PendulumAmi Varsano2023-01-06 | Thirteen uncoupled pendulums of monotonically increasing lengths, swing together by electronic oscillators to display patterns that look like traveling wave, standing wave, and beat mode.
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
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, 2014Lego Damped Wave PendulumAmi Varsano2022-05-22 | A set of uncoupled Lego pendulums, monotonically decreasing in length, display patterns that alternately look like traveling waves, standing waves, and chaos.
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
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, 2014Lego Wind Turbine Generates ElectricityAmi Varsano2022-03-05 | Lego wind turbine produces switching electrical power with electromagnetic generator and bistable multivibrator. All components are displayed and described in detail.
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
Music Title: “Nightlife” Composer and Acoustic Guitar: Michael Kobrin Album: “Searching”, Released 2016 Mastered at Turtletone Studios, NYC, U.S.A.Lego Clock Escapement with Tension SpringsAmi Varsano2022-02-04 | Mechanical oscillator whose frequency is regulated by tension springs. The springs are calibrated to produce different frequencies.
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:
Music Title: “Nightlife”, Composer and Acoustic Guitar: Michael Kobrin Album: “Searching”, Released 2016 Mastered at Turtletone Studios, NYC, U.S.A.Lego Coupled PendulumsAmi Varsano2022-01-16 | Beat-mode period is calculated from in-phase and out-of-phase oscillations. A mathematical model represents the motion.
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
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.Lego Double-Stack Balance-Wheel Verge EscapementAmi Varsano2021-12-04 | Verge escapement with balance-wheel assembly, modeled after the Royal Oak wristwatch by Audemars Piguet, a Swiss watchmaker.
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:
Music Title: Anomalous Hedges Artist: Mini Vandals Album: Anomalous Hedges, Released 2021Lego Dual Balance-Wheel Verge EscapementAmi Varsano2021-11-02 | This video: Verge escapement, regulated by hairsprings + tutorial on making your own spring.
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:
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.”Lego Verge EscapementAmi Varsano2021-10-09 | Verge escapement, tested with several modes of regulation, including inertial oscillator, magnetic repulsion, varying weights, and balance spring.
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:
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 BarenboimRotts Chaotic PendulumAmi Varsano2021-08-15 | Rott’s damped double pendulum exhibits two modes of motion: regular, linear, and predictable, the other is chaotic, nonlinear, and unpredictable.
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
Music Title: Down The Street Blues Artist: Unicorn Heads Album: River Radio, Released 2018Double Pendulum Chaotic GymnasticsAmi Varsano2021-07-11 | Bar-and-ring double pendulum oscillates in a surprising way that defies intuition. The pendulum is a damped mechanical oscillator whose energy dissipates continuously after it is set in motion.
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.”
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: 1959Double Pendulum Chaotic AcrobaticsAmi Varsano2021-06-13 | Bar-and-ring double pendulum oscillates in a surprising way that defies intuition. The pendulum is a damped mechanical oscillator whose energy dissipates continuously after it is set in motion.
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.
Music Title: By the Fireplace Artist: TrackTribe Album: By the Fireplace, Released 2020Self-Assembling Wires in Petri Dish with High VoltageAmi Varsano2021-04-19 | Tiny balls form chains that behave like living worms in Petri dish with high voltage.
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 NelssonLego Verge and Foliot Clock Escapement TransformerAmi Varsano2021-04-02 | In 1673 Christiaan Huygens built the first clock with a pendulum replacing the foliot to improve accuracy of time measurement.
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/UbVOHz7hV9sLego Crown-Wheel Clock EscapementAmi Varsano2021-03-25 | Lego verge and pendulum escapement modeled after Christiaan Huygens’ 1673 escapement, with the foliot replaced by a pendulum attached to the verge for better accuracy.
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_ZLtGwLego Torsion Pendulum Clock Escapement – 6 ProngsAmi Varsano2020-11-12 | Gravity-run mechanical torsion-pendulum oscillator automates the old button-and-string toy, called whirligig or buzzer toy.
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/yL8SlcBac5sLego Torsion Pendulum Clock EscapementAmi Varsano2020-11-05 | Watch 360-degree view of a mechanical torsion-pendulum oscillator that automates the button-and-string toy known as whirligig.
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/yL8SlcBac5sLego Coupled Torsion Pendulum Clock Escapement – Button SpinnerAmi Varsano2020-10-03 | This button spinner is a mechanical oscillator, regulated by coupled torsion-pendulum, and run by the force of gravity.
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.
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/yL8SlcBac5sLego Torsion Pendulum Clock Escapement - 3 ProngsAmi Varsano2020-09-18 | Clock escapement, regulated by torsion pendulum, automates the age-old button-and-string toy, called whirligig or buzzer toy. This mechanical oscillator is powered by the force of gravity.
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/yL8SlcBac5sSpinning Top Ring Magnet Energized and ReleasedAmi Varsano2019-10-12 | Spinning top is spun manually, then driven by an electronic circuit. After spinning is stabilized, power is turned off. The top continues spinning for over 3 minutes, then collapses.
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
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_g8Swirling Spiral Phenakistoscope on Paper Towel Dispenser MotorAmi Varsano2019-10-10 | Swirling spiral of bubbles is rotated at 48 RPM by DC gear motor from paper-towel dispenser. 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.
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/MjuReCiZBbILego Anchor Escapement Regulated by Dual SpringAmi Varsano2019-09-21 | Two cylindrical springs, suspended from balance bar, regulate frequency of oscillation of anchor escapement with pinwheel. The entry pallet (yellow) is on the right side of the arbor while the exit pallet (red) is on the left.
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_QLego Anchor Escapement Regulated by Cylindrical SpringsAmi Varsano2019-09-20 | Two cylindrical springs, suspended from balance bar, regulate frequency of oscillation of anchor escapement with pinwheel. The entry pallet (yellow) is on the left side of the arbor while the exit pallet (red) is on the right.
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/4uXJq9ZGnbMLego Anchor Clock Escapement with Balance Arm PendulumAmi Varsano2019-09-19 | The balance arm pendulum is pivoted on knife edge suspension which offers significantly lower friction than axle in plain bearing. My thanks to fellow YouTuber KEvron who had posted videos comparing the two types of suspensions and demonstrating the advantage of one over the other.
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.Lego Torsion Spring Pendulum Clock EscapementAmi Varsano2019-07-13 | The pendulum is suspended from wire torsion spring of 1954 model Schatz Standard 54, 400-Day Clock. Spring thickness is 0.102mm (4 mil).
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/Gleg2dWei8ELego Pinwheel EscapementAmi Varsano2018-08-10 | The pinwheel escapement was invented about 1753 by French clockmaker Jean-André Lepaute. This escapement was used in turret clocks with a mechanism to drive large dials and bells mounted high in town-hall buildings for public display or in church towers. An objection to using this escapement is the difficulty in keeping the pins oiled. Except for turret clocks, this escapement may be regarded obsolete.
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.
Reference: The Encyclopedia Britannica, A Dictionary of Arts, Sciences, And General Literature, Volume VI. 1877Lego Pinwheel Escapement with 6 PinsAmi Varsano2018-08-07 | The pinwheel escapement was invented about 1753 by French clockmaker Jean-André Lepaute. This escapement was used in turret clocks with a mechanism to drive large dials and bells mounted high in town-hall buildings for public display or in church towers. An objection to using this escapement is the difficulty in keeping the pins oiled. Except for turret clocks, this escapement may be regarded obsolete.
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.
Reference: The Encyclopedia Britannica, A Dictionary of Arts, Sciences, And General Literature, Volume VI. 1877Triple Pendulum Chaotic AcrobaticsAmi Varsano2016-08-14 | The pendulum oscillates harmonically when displacements from equilibrium are small. Motion turns dramatically chaotic and unpredictable when displacements are large.
"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.
Reference: Make magazine Volume 22, June 2010.Lego Coupled Pendulum in ResonanceAmi Varsano2016-06-11 | Two identical pendulums coupled by weak repelling magnetic field, oscillate and exchange energy.
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.
Rott's Chaotic Pendulum: youtu.be/roJDKBClVvc Electrostatic Coupled Oscillator with Door Chimes: youtu.be/RkG3bql3HjwSwinging Ball Magnet Impulses Lego Clock EscapementAmi Varsano2016-05-14 | Ball magnet swings along plastic track and transmits periodic impulse to escape wheel.
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-Xh3Hm4Lego Coupled Torsion Pendulums Clock EscapementAmi Varsano2016-02-26 | Pendulums suspended from common sewing cotton thread convert rotary motion into linear that steps escape wheel when horizontal arm seesaws. Gear train was added.
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"
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/yL8SlcBac5sLego Coupled Torsion Pendulums Clock Escapement V.1Ami Varsano2016-02-20 | Pendulums suspended from common sewing thread convert rotary motion into linear that steps escape wheel when horizontal arm seesaws.
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/yL8SlcBac5sLego Clock Escapement with Coupled Torsion PendulumsAmi Varsano2016-01-21 | Pendulums suspended from common sewing thread convert rotary motion into linear one that steps propeller when horizontal arm seesaws.
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:
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/yL8SlcBac5sSpinning Top Motor-GeneratorAmi Varsano2015-12-18 | Flip-Flop with inductive load drives spinning-top magnet rotor. After power is turned off, the rotor transfers some energy back to the driver.
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/fVc2zLdsbqgTorsion Pendulum Delivers Torque to Magnetic RotorsAmi Varsano2015-12-06 | Magnetic torsion pendulum transmits torque to magnetic rotors. The pendulum is driven by a Flip-Flop which is triggered by the swinging pendulum.
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.
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.
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/fVc2zLdsbqgLego Rack and Pinion Lever EscapementAmi Varsano2015-04-09 | Linear gear bar at top of pallet lever sways from side to side. The bar engages a circular gear on balance wheel which oscillates between two magnets.
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.Lego Clock Lever EscapementAmi Varsano2015-02-12 | Dual escape-wheel rocks pallet-lever which strikes a balance- wheel. Neodymium magnet at top of balance-wheel oscillates between a pair of magnets.
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.Lego Double-Wheel Clock Escapement with Magnetic Balance WheelAmi Varsano2015-01-17 | Two counter-rotating interlocking cogwheels with propellers. Locking/unlocking is made on the left while impulse transfer is on the right.
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.Lego Clock Escapement with Balance Wheel V.3Ami Varsano2014-11-01 | Third version of escapement regulated by balance wheel, oscillating between two stationary neodymium magnets.
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.Lego Clock Escapement with Magnetic Balance WheelAmi Varsano2014-10-30 | Second version of escapement regulated by balance wheel with neodymium magnet, oscillating between two stationary ones. The wheel was balanced for equal distribution of mass, prior to mounting stationary magnets on the frame.
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.Lego Clock Escapement with Balance Wheel V.1Ami Varsano2014-10-21 | Escapement regulated by balance wheel with neodymium magnets, on opposite spokes, which collide elastically with stationary magnets.
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...Lego Tumbling Acrobat AutomatonAmi Varsano2014-08-11 | Lego automaton descends down a staircase; as bearing balls roll down inside hollow tubes, the momentum from gravity swings the lighter end of tubes forward.
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/VXvezNiOlGcLego Tumbling AutomatonAmi Varsano2014-06-17 | The tumbling car contains a bearing ball which can roll freely on a track along the length of the car. Two pivots which extend from the car are offset from the axis of the ball-track. As the ball rolls to the end of the track, momentum from the force gravity swings forward the lighter end of the car.