Budget physics

Acrylic Rattleback

These acrylic versions work great and are inexpensive: 

From STEMCell Science: BUY NOW: Rattlebacks  

Acrylic Rattleback: a favorite from my collection- prefers to spin counter clockwise. If spun clockwise, a complicated combination of friction, precession, and instability induced vibrations transforms the rotational energy into into rattling (energy of oscillations) and then into rotational energy in the opposite direction! This behavior is related to the asymmetric shape of the bottom of this kind of rattleback, it's somewhat propeller shaped with an "S" curve along the bottom ridge

Chaotic Decision Pendulum

Get this device here:

From eBay: BUY NOW: Chaotic Decision-Aider Pendulum

From Amazon: BUY NOW: Chaotic Decision-Aider Pendulum

Chaotic Decision Maker Pendulum: adding magnetic forces to gravity gives this comical pointing pendulum chaotic motion- not random, but very sensitive to slight differences in initial launch conditions. Each “choice” has a dipole magnet underneath which attracts a magnet in the hand and locks the pointer into place, but only after enough kinetic has been dissipated, and until that final state is obtained the motion is chaotic. Fun physics behind this novelty gag gift.


Newtons Yo-Yo

Get a set here: 
From Educational Innovations: BUY NOW Newton's Yoyo 
 

Newton Yo Yo: Newton's 3rd Law states that action force equals opposite reaction force- the the green and yellow spheres have equal mass, so the forces of the collision provide accelerations that are equal and opposite such that the spheres trade places.

Drinking Dino Heat Engine

This dinosaur themed heat engine available here:

From Amazon: BUY NOW: Drinking T-rex Desk Toy

Get also: the related Drinking Bird Heat Engine 

Drinking Dino Heat Engine: So what physics presents did you get this year? I got this Dippy Dino heat engine- where cooling by evaporation at the head leads to lower pressure in the top bulb such that the dichloromethane fluid (colored green) rises up the neck making the T-Rex top heavy and the dino tips over dipping its face in the water and letting the fluid return to the bottom bulb. The process repeats as long as the top stays wet. A fun and silly variation on the famous drinking bird physics toy- and the T-Rex was a closely related ancestor to the dinosaurs that live today- birds! 


Scale Solar System Sticker Set

Get this fantastic set here:
From TheCuriosityBox: BUY NOW: Scale Solar System

This set came in my Curiosity Box subscrition. A great way to start collecting your own physics toys (and other brain food):
From the Vsauce team: BUY NOW: The Curiosity Box

Scale Solar System Sticker Set: one of the most amazing facts about the planets in our solar system is their relative sizes. Finally! a set of stickers- made to scale- using images from NASA, brought to you by the Vsauce team @thecuriositybox. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and dwarf planet Pluto included for comparison- all in their current order (sometimes Pluto is closer than Neptune), and mounted here on a sheet of polycarbonate.

Mirascope

Similar devices available here:
From Educational Innovations: BUY NOW Mirascope 
From Amazon: BUY NOW Mirascope 
 

Mirascope: two parabolic mirrors create a 3D image above the actual object. A repost of one of my favorite physics toys ever. The image of the dice made here is not a hologram and is produced solely by reflection of light rays between special concave mirrors. Discovered circa 1969 by Landry and Elings at UC Santa Barbara.

TrueBalance

Get the full version (8 disks made of wood) or the mini (6 disks, blue or red plastic): 
From Amazon: BUY NOW TrueBalance Coordination Puzzle 

TrueBalance: coordination challenge puzzle- get the six disks, connected by bearing swivels, into a vertical stack by only tilting the handle. Harder than it looks to get each disk’s center of mass above the one below at the same time into the unstable equilibrium final state. The swivels constrain the system, limiting the degrees of freedom, and allowing strange and interesting motion. Kinetic art as a toy! 


Electric Motor Build

Get an easy to assemble kit here (or just buy the replacement wire to build your own like in the video): 
From Educational Innovations: BUY NOW Simplest Motor Kit 

Electric Motor Build: One of the most important inventions consists of only three basic components as shown here: coil, magnet, and a battery with lead wire posts. The wire of the spinning coil has an insulating coating on it- and this coating is carefully scrapped off one side of the thin wire on each end. When current passes through the coil it becomes an electromagnet and the permanent magnet repels it making it spin- as it turns the current goes on and off depending on if the copper wire posts are in contact with the bare wire side (current on) or the part of the wire with the insulating coating intact (current off). When the current is off momentum keeps the rotation going until the next push. The physics of converting electric energy to rotational kinetic energy- and a fun DIY project! 

Pikachu Phonotrope Spinner

Get this fun spinner here:

From Etsy: BUY NOW: Pikachu Animation Spinner

Phonotrope Spinner: When viewed through video from a smartphone an animated Pikachu springs into motion. The laser cut and printed acrylic is specifically designed to interact with the frame rate of the video process, similar to the animation effect of a flip book, but in a repeating cycle. The effect can also be seen without a camera by using a mirror and viewing through the spaces between the cutouts (swipe to see demo which looks much better in person)- using a mirror like this turns the spinner into a phenakistiscope, the 1833 invention that started moving media animation that lead to the development of movies and video. 

Crushmetric Holographic Foil Pen

Available here:

From Crushmetric: BUY NOW: Crushmetric Pen

From Art of Play: BUY NOW: Switch Pen

Crushmetric Holographic: the Switch Pen with diffractive rainbow foil- functional kinetic art based on materials science and tessellation origami techniques. The crushed state can be reversed over and over in this incredible design by artist/inventor Noah Deledda, also known for his similar sculptures created from aluminum cans. 


Mini Wind Turbine

Nice little unit for the price! 
From eBay: BUY NOW Mini Wind Turbine 
From Amazon: BUY NOW Mini Wind Turbine 

Mini Wind Turbine: self-contained miniature horizontal axis wind turbine generates enough power to light three LEDs. A small turbine blade is attached to the rotor of a tiny generator that powers the LEDs. Conversion of energy- wind kinetic energy to rotational kinetic energy to electrical energy to light energy. I like how the wind vane and tower are also designed from acrylic as light pipes for the LED light. A fun little toy that demonstrates the physics of renewable energy!

Drinking Bird Heat Engine

Get this famous physics toy from these sources: 
From Educational Innovations: BUY NOW 
Drinking Bird Engine 

From Amazon: BUY NOW 
Drinking Bird Engine 


Wikipedia has wonderful details about the rich history (and further descriptions of the operational principals) of the Drinking Bird
Drinking Bird Heat Engine: time lapse of 15 minutes into 15 seconds (4 cycles). Cooling by evaporation at the head leads to lower pressure in the top bulb, the dichloromethane fluid rises up the neck making the bird top heavy and the bird tips over dipping its beak and letting the fluid return to the bottom bulb. The time lapse allows a clearer picture of how the fluid rises, shifting the center of mass, and how tipping makes the glass column lift out of the fluid in the bottom allowing the pressure to equalize and letting gravity pull the fluid to return to the base. Process repeats as long as the top stays wet. So much physics in one hypnotic toy!

Mini-Lollipopter

Available here:

From Amazon: BUY NOW: Lollipopter Kinetics

From eBay: BUY NOW: Lollipopter Kinetics

Mini-Lollipopter: new smaller cousin of one of my favorite interactive kinetic sculpture designs. A snap of the wrist imparts angular momentum to the "petals" which then rotate until an internal mechanism stops their motion with predetermined spacing- clockwise rotation transforms a helix to an abstract pine cone, counterclockwise returns the helix. Created by @john.edmark.


Hyperbolic Holes

This inexpensive kit available here:

From Amazon: BUY NOW: Hyperbolic Holes Kit

Hyperbolic Holes: a straight rod, in this case a pencil, glides through a symmetrical pair of curved holes. The design is based on the hyperboloid, the 3D ruled surface traced by an offset rotating diagonal line. This device is sold as an inexpensive kit to assemble yourself, and includes a motor with geared drive and pre-cut pieces. The pencil is my addition- sharpened to just the right size to clear the curved openings.