Fun Devices: Engine DIY

Disk Tesla Coil

Create amazing Telsa coil lighning at an affordable price! Please be sure to employ all appropriate safety precautions when utilizing any electrical circuity.  

From engineDIY: BUY NOW: Disk Tesla Coil

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Disk Tesla Coil: incredible coronal brush discharges form intricate miniature lightning in this variation of the famous air core double-tuned resonate transformer invented by Nikola Tesla in 1891. In this novel design the coil is created using modern printed circuit board (PCB) technology producing a spiral of many conductive windings, so thin and close together it looks a bit like a gold phonograph record. The 10 cm long sparks are made possible by a very high voltage, but also a very fast discharge of a capacitor, and each lightning flash is accompanied by a dramatic popping sound characteristic of capacitor discharge (shown up close in 240fps slow motion). Powered by a 24V DC supply, this unit is fairly safe due to a low current (mA)- the discharge feels like a light tickle (but don’t touch the electrode- it gets hot). 

Simple Stirling Engine

Get this amazing model engine here:

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.

Tesla Coil

For the price, this is the best one on the market I think and beautiful to look at in copper- the music function does not do much, but it is a great little Tesla coil and it comes with three accessories for the top. Please be sure to employ all appropriate safety precautions when utilizing any electrical circuity! 

From engineDIY: BUY NOW: Mini Tesla Coil

Tesla Coil: miniature low current version of the famous air core double-tuned resonate transformer invented by Nikola Tesla in 1891. The thick copper of the primary coil is set into three windings around the many windings of the tall secondary coil. This one uses a modern transistor circuit to excite the radio frequency oscillations that produce a voltage in excess of 50kV in the form of pulses that cycle about 100k times a second. This version is fed by a 24V DC power supply and is fairly safe due to a low current (mA)- but the circuitry does get hot and demands a huge heat sink with fan (the metal base can burn skin when operating). The coils comes with attachments- the spike produces a purple corona discharge as the voltage exceeds the breakdown voltage of air with current flowing into the air or arcing over to a grounded piece of metal. The corona discharge imparts momenta, and here the ends of a bent wire are set into rotation from the slight push of the escaping electrons. Swipe to see the ejected electron stream propel the end of a thin wire 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. 


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. 

 

 

Vertical Mendocino Motor

Get this device for a great price here:

From EngineDIY: BUY NOW: Vertical Mendocino Motor

Vertical Mendocino Motor: each face of solar cell is connected to a coil of copper wire. Spins fast and quite in a sunny window. As the rotor turns each solar cell takes a turn in the brightest light, which provides electric current to one of the coils which becomes a temporary electromagnet that pushes against the permanent magnet configuration in the center- propelling the rotor to rotate. The rotor assembly is nicely symmetric and balances on a sharp point for minimal friction. Invented in the 1960s by Daryl Chapin of Bell Labs and popularized by Larry Springs of Mendocino CA 

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 Luciteria: 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. 


Oscilating Cylinder Steam Engine

Get this tiny working engine here: (brass and stainless steel) 

From engineDIY: BUY NOW: Tiny Steam Engine

Two other similar mini-engines to consider: BUY NOW: Mini-Steam 1, Mini-Steam 2 

Oscillating Cylinder Steam Engine: a functional “wobbler” type piston steam engine complete with boiler and flywheel. In this design the cylinder and piston both rock back and forth, acting as the valve mechanism to allow the hot steam to enter through a small hole, and then exit on the next stroke out through the tiny exhaust port in the top. Takes about 4 minutes to get going after the lamp is lit. A tiny version of the invention that powered the industrial revolution.

Hero's Engine

This live steam engine is available here:

From EngineDIY: BUY NOW: Hero's Engine

Hero’s Engine: the very first steam engine ever devised, the Aeolipile is a radial steam jet reaction turbine, an a invention attributed to Hero of Alexandria in the year 1 AD. Water within the spherical container is heated to produce steam which exits through nozzles directed at right angles to the radial direction, and by Newton’s third law these jets produce a torque about the rotation axis. There is no historical record of this engine being put to practical use in ancient times- except perhaps as the world’s first physics toy!

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!

 


Mendocino Motor

Get one here: 

From engineDIY: BUY NOW Solar Levitating Motor (on all models here-remove brown protective film to reveal clear acrylic on rotor)

From Amazon: BUY NOW Solar Levitating Motor 

Mendocino Motor: each face of solar cell is connected to a coil of copper wire under the opposing solar cell. When the rotor is lit from above the top solar cell provides electric current to the coil in the bottom position which becomes a temporary electromagnet that pushes against the permanent magnet in the base propelling the rotor to rotate. As the rotor turns, the coil that moves into the bottom position is likewise energized by the solar cell currently at the top- one can say the light commutates this motor. 2D magnetic levitation is provided by permanent magnets where an acrylic plate constrains the third dimension, and makes for a nice bearing surface for minimal friction. Invented in the 1960s by Daryl Chapin of Bell Labs and popularized by Larry Springs of Mendocino CA 

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.

 

Electromagnetic Levitation Module 

Get this 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 Engine DIY: 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

Element 10: Neon 

Luciteria (highly recommended) sells this cube and 80 other elements in many formats- start your collection today! 

From Luciteria: BUY NOW: Lucite Cube Element 10 Neon

Need a mini Tesla Coil? Click here for details: Mini Tesla Coil 

Element 10, Neon: a pure sample of the famous noble gas in a glass ampule encased within a lucite cube. But how can we know that the glass tube is actually filled with neon gas? If the sample is brought near the 50,000 Volt high frequency electric field of a miniature Tesla coil, the gas will glow with the characteristic orange light from the electron energy transitions specific only to neon. Note that the glow deceases as the sample is moved away from the coil in proportion to the electric field intensity- and that there is an excitation threshold, the gas needs a higher intensity (closer to coil) to initiate the glow discharge but will still glow when moved further away.