Simple Stirling Engine
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From EngineDIY: BUY NOW: Simple Stilring Engine
See other featured DYI devices here: EngineDIY Models
Simple Stirling Engine: Perhaps the simplest piston engine ever devised- a single piston powered by a tiny alcohol lamp. Glass components allow a view of the internal workings of this design, and the interesting startup behavior from oscillation to full rotation. Heat engines produce mechanical motion from a difference in temperature- here the piston side is near room temperature (the central aluminum post is an excellent conductor and acts as a heat sink as the gas flows through), and the test tube is kept at high temperature via the flame, with metal fibers to help conduct the heat into the air (this component is called the regenerator). Swipe to see the elegant assembly of this model, and swipe again to see the engine power down. This external combustion design is attributed to Scottish engineer Robert Stirling back in 1816.
Precision Stirling Engine
The Kontax KS90 Stirling Engine is guaranteed to run off the heat of your hand!
From eBay: BUY NOW: Kontax KS90 Engine
Less expensive models will run off the heat from a cup of coffee/tea:
From engineDIY: BUY NOW: Stirling Engine
Precision Stirling Engine: low temperature difference engine turns body heat into mechanical motion. For this engine the heat source is my hand, and the heat sink is the room temperature air- warming the bottom black plate with only the heat of my hand will set this engine running for several minutes. This beautiful KS90 engine is manufactured with precision machined parts by Kontax Engineering Ltd.
Solenoid Magnetic Accelerator
Get this and similar devices here:
From EngineDIY: BUY NOW: Steel Ball Cyclotron Accelerator
Solenoid Magnetic Accelerator: six electromagnet coils push a steel ball to terminal velocity. Each coil is triggered to briefly energized only when an infrared led and sensor circuit detects the presence of the ball. The steel ball’s speed seems limited by the strength of the temporary magnetic field and the friction it encounters from the track. This ring configuration demonstrates proof of concept for a means of accelerating steel marbles and I hope to incorporate these coils in other marble run designs I will share in the future. Uses a 12V power supply.
Vertical Mendocino Motor
Get this device for a great price here:
From EngineDIY: BUY NOW: Vertical Mendocino Motor
From engineDIY: BUY NOW Horizontal Levitating Motor (on all models here-remove brown protective film to reveal clear acrylic on rotor)
Mendocino Motor: vertical and horizontal versions- each face of a solar cell is connected to a coil of copper wire across from the opposing solar cell. When the rotor is lit from one side the lit solar cell provides electric current to the coil in the opposite position which becomes a temporary electromagnet that pushes against the permanent magnets in the base propelling the rotor to rotate. As the rotor turns, the coil that moves into the position near the magnet is likewise energized by the solar cell currently at the top- one can say the light commutates this motor. Magnetic bearings to reduce friction in both models. Invented in the 1960s by Daryl Chapin of Bell Labs and popularized by Larry Springs of Mendocino CA
Stirling Engine
Get this very nice working model engine here, choose a configuration:
From EngineDIY: BUY NOW: Stirling Engine
From EngineDIY: BUY NOW: Stirling Engine with Generator
From EngineDIY: BUY NOW: Stirling Engine Simple Vehicle
Stirling Engine: an elegant model of an external combustion heat engine with dual reciprocating pistons which operates by cyclic compression and expansion of air. Heat one cylinder with the cute little alcohol burner and this model gets up to speed quickly. Pyrex glass allows one to view the hot cylinder in operation (shown here in slow motion) and this version of the model includes a small generator to convert some of the mechanical energy into electrical energy which then powers some LED lamps. This design is attributed to Scottish engineer Robert Stirling back in 1816- a working piece of the industrial revolution for your desk top!
Tesla's Egg of Columbus Replica
Get an amazing reproduction here:
From engineDIY: BUY NOW: Tesla's Egg of Columbus
Get an aluminum phiTOP "egg" here: BUY NOW phiTOP
Tesla’s Egg of Columbus Replica: an egg of brass mysteriously spins and stands upright in this museum quality replica of Tesla’s famous demonstration from the 1893 World’s Fair in Chicago that first showcased the principles behind wireless power transfer and his AC induction motor. The base has no moving parts- instead special copper windings (very similar to Tesla’s original design) form four electromagnet coils on a circular steel core, and a special circuit supplies each with AC currents in such a way that a rotating magnetic field is created. This rotating magnetic field from the coils under the concave glass induces electric eddy currents to flow in the metallic brass egg. These currents within the conducting metal of the egg then create their own magnetic field, which by Lenz’s law oppose the initial fields underneath and pushes the egg to spin. Finally, the oblong egg stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top. Flipping the switch reverses the rotation direction induced by the coils.
Electromagnetic Levitation Module
Get a similar inexpensive simple module here:
From EngineDIY: BUY NOW: Mag Lev Kit
Electromagnetic Levitation Module: this bare bones engineered control system uses an adjustable electromagnet (the copper coil) and a Hall effect magnetic field sensor (embedded in the center of the the coil) to levitate a neodymium magnet and keep it from falling. A feedback loop informed by the Hall effect sensors allows fine tuning of the magnetic field to exactly balance the pull of gravity, all powered by a 12 power supply. Once trapped the magnet can also rotate, creating a nice way to display a small piece of kinetic illusion art hanging from a chain. A no frills design that shows the fairly simple circuit and components of such a levitation feedback system.
Electromagnetic Levitation Module
Get this kit here (comes complete as shown in my video):
From engineDIY: BUY NOW: Magnetic Levitation Module
The featured sculture is by Bathsheba Grossman, affordable and beautiful math art available here:
From Etsy: BUY NOW: Soliton Sculpture
Electromagnetic Levitation Module: this engineered control system uses adjustable electromagnets (four copper coils) and and two Hall effect magnetic field sensors (held firm embedded in white silicone) to levitate an 5cm diameter neodymium magnet platform about 3 cm in mid-air. A feedback loop informed by the Hall effect sensors allows fine tuning of the magnetic field to exactly balance the pull of gravity, and is powered by a standard USB connection. The platform also rotates, perfect for showcasing one of my metal 3D printed mathematical sculptures by Bathsheba Grossman.
Wimshurst Electrostatic Generator
Get this inexpensive version that makes big sparks!
From EngineDIY: BUY NOW: Wimshurst Electrostatic Generator
Wimshurst Electrostatic Generator: this device uses two counter rotating disks of metal pads to separate charge via induction. The repulsion felt by electrons as the triangle plates pass by each other pushes charge to flow across two conducting rods, one on each side, which allows the charge to stack up. This excess charge is then stored in old fashioned cylindrical capacitors (Leyden Jars) until the resulting 30,000+ Volts is achieved to jump the air gap. This device goes back to 1883- invented by James Wimshurst.
Corona Discharge Trajectories
Mini Tesla coil with wire end attachment- get one here:
From engineDIY: BUY NOW: Mini Tesla Coil
Long exposure image captured using this Slow Shutter app:
From App Store: BUY NOW: Slow Shutter Cam
Corona Discharge Trajectories: the ejected electron stream propels the end of a thin wire connected to a miniature Tesla coil. The corona discharge creates a glowing plasma at the end of the wire, but also imparts momenta that pushes the wire’s end into a final state circular orbit. The more interesting behavior occurs during the initial transient orbits which seem to be hypotrochoid type curves beautifully captured here using the Slow Shutter app. Please see seven posts back for details about this mini Tesla coil.
Stirling Engine
Get this beautiful little engine here:
From EngineDIY: BUY NOW: Stirling Engine
Stirling Engine: a very pretty and fully functional model of the famous external combustion heat engine, powered here by a tiny alcohol lamp (with an almost invisible flame). Heat engines produce mechanical motion from a difference in temperature- here the glass cylinder and piston side is kept at high temperature via the flame (to expand the gas within), and the cool side is the metal cylinder and displacer piston which acts as a heat sink to re-cool (and contract) the gas and then send it back to be heated again each cycle. This module also includes a tiny generator and LED circuit. Swipe to see more detail and watch the engine power up. This closed-cycle regenerative heat engine design is attributed to Scottish engineer Robert Stirling back in 1816.
Thermobile: Nitinol Loop Engine
Get this amazing heat engine here:
From EngineDIY: BUY NOW: Nitinol Loop Heat Engine
Get a sample of Nitinol wire here:
From Educational Innovations: BUY NOW Nitinol Memory Wire Spring
Thermobile: Nitinol wire loop heat engine- the memory wire straightens out when heated (contact with heat conducting small wheel) causing the wheels to spin, providing mechanical kinetic energy from a cup of warm tea water. Swipe for a demonstration of Nitinol wire, a special alloy of nickel and titanium that can be trained to a specific shape at high temperature- bend it up at room temperature and it will snap back into shape when exposed to moderate heat such as hot tea water. This remarkable property is a type of solid state reversible phase transition known as a martensitic transformation.
Mini Acoustic Levitator
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From EngineDIY: BUY NOW: Mini Acoustic Levitator
Mini Acoustic Levitator: small pieces of styrofoam become trapped between areas of higher pressure induced by high frequency sound waves. Ultrasonic transducers placed at the top and bottom are basically speakers that emit sound waves at a frequency of 43,000 Hz, which corresponds to a wavelength of 8mm for dry air. If the transducers are positioned just right standing waves are produce with nodes of low pressure at half wavelength intervals- and low mass objects like these foam pellets will be suspended against gravity when placed near one of these nodes. Here we see a stack of three pellets with a spacing of about 4mm which is the expected distribution of the nodes. To place the pellets into the sound stream without disrupting the standing waves this device comes with a small screen with a handle which allows the sound waves to flow through the holes in the mesh and trap piece of foam. Although the device uses sound it appears silent as the frequency used is way above that which humans can hear (20Hz to 20kHz).
Tesla's Egg of Columbus
Get this amazing (and affordable) reproduction here:
From engineDIY: BUY NOW: Tesla's Egg of Columbus
This version comes with a 35mm solid aluminum sphere.
Get the aluminum phiTOP "egg" here: BUY NOW phiTOP
Tesla’s Egg of Columbus: an aluminum ellipsoid egg (PhiTOP) mysteriously spins and stands upright in this modern version of Tesla’s famous demonstration from the 1893 World’s Fair in Chicago that first showcased the principles behind wireless power transfer and his AC induction motor. The base has no moving parts- instead special copper windings (very similar to Tesla’s original design) form four electromagnet coils on a circular steel core, and a special circuit supplies each with AC currents in such a way that a rotating magnetic field is created. This rotating magnetic field from the coils under the concave glass induces electric eddy currents to flow in the aluminum ellipsoid- these currents then create their own magnetic field which oppose the initial fields underneath and pushes the ellipsoid to spin. Finally, the ellipsoid top stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top.
Emission Spectra Gases on Radial Mount
I made the display holder and I got this set of gas tubes here (about $9 per tube):
From eBay: BUY NOW: Gas Pure Element Samples
From engineDIY: BUY NOW: Mini Tesla Coil
For the price, this is the best one on the market- and beautiful to look at in copper- and it comes with three accessories for the top. Please be sure to employ all appropriate safety precautions when utilizing any electrical circuity!
The mount is made by driling holes in this acrylic tube: 4" Acrylic Tube
The breakdown voltages of the elements featured in this post are described by Paschen's Law:
Here is a excellent article with an overview of the physics of glow discharge and its application in lighting and other technologies.
Click this link to see the mini Tesla coil in action
Emission Spectra Gas Samples: pure samples of hydrogen, nitrogen and five noble gasses are subjected to the high frequency pulsed field of a miniature Tesla coil. Each gas has a characteristic breakdown voltage and emission spectrum- note that Nitrogen has the highest breakdown voltage and begins to glow after the presence of my hand temporarily lowers the resistance to current flow for that tube. The color of each gas is due to a mix of the colors emitted from electron energy transitions specific to each element- the basis of spectroscopy. Notice also that the purple color of the brush discharge at the top of the Tesla coil matches closely to the color of the nitrogen sample, which makes sense as air is 78% nitrogen.
Handheld Tesla Coil
Get this spark generator here:
From EngineDIY: BUY NOW: Handheld Tesla Coil
See other inexpensive tesla coils in my collection
Handheld Tesla Coil: each pull of the trigger discharges a large capacitor (seen through the clear window) with a loud pop and a tiny lightning bolt then streaks from the tip. In this variation of the famous air core double-tuned resonate transformer invented by Nikola Tesla in 1891, the 10 cm long sparks are made possible by a very high voltage, but are made fairly safe due to a very low current (mA)- the discharge feels like a light sting (but don’t touch the electrode- it gets hot). This battery powered version is friendly for demonstrations, such as exciting an ampule of neon gas to glow brightly during the high voltages discharges (swipe to view in slow motion).
