Useless but fun little mechanisms that click, clack and move when you turn, push or shake them. 42 items
A star-shaped wheel advances exactly one step and stops for each full turn of the knob disc. The pin on the disc drives the wheel only while it is inside a slot, and an arc on the disc is designed to hold the wheel still the rest of the time, so you can watch it turn in clicking steps in your hand. Four versions with different slot counts (4, 5, 6 and 8) can be made.
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Two blocks move back and forth at right angles in a cross-shaped slot, and the knob at the end of the arm is designed to trace an ellipse. It is a toy for simply tracing the knob around with a finger and enjoying a motion that produces nothing. Versions with three slots in a triangular layout, or with a different arm length to change how narrow the ellipse is, can also be made.
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Two discs with thin gaps are stacked on a center shaft. Hold them up to the light and turn one, and the overlapping gaps are meant to appear as large stripes drifting across. You play by watching how the stripes look. Combinations with different patterns can be made: parallel lines, radial lines, concentric circles and spirals.
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Two shafts at different heights have a middle disc with cross-shaped tabs between them. When you turn the handle, the middle disc slides along the slots and is designed to pass the rotation on even though the shafts are offset, so you can try the mechanism known as an Oldham coupling by hand.
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Three pins stand on a disc inside a tube. Pressing one pin tilts the disc and is designed to push the other pins up. Each press moves a different pin, so you will want to press them in turn. Variations with two to five pins, or with different head shapes, can be made.
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A one-piece toy in which four thin diagonal beams hold a block inside a frame. Pressing the block bends the beams, and partway through they are designed to snap over to the other side and stay there, so you can enjoy the feel of the switch in your fingertips. Three versions with different beam angles and thicknesses, and so a different feel, can be made.
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Several stages of crossed bars joined with pins form a scissor linkage. Bringing the two rings at the base together is designed to extend the tip forward. You play by squeezing and opening the rings and watching the arm stretch and retract. The number of stages can be set to 3, 4 or 5, and the tip can be changed to an arrow, a circle and so on.
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Six small plates are joined alternately with flat cord. Flipping the top plate is meant to make the plates below turn over one after another. You play by watching the corded plates flap along in a row. Versions with raised patterns on the front and back, or with 4, 6 or 8 plates, can be made.
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Tetrahedra are hinged into a ring, and pushing it toward the center of the ring is designed to bring the inner faces out. The turning-inside-out can go on with each push, so you will want to keep turning it in your hands. Versions with 6, 8 or 10 tetrahedra, or with raised patterns on the faces, can be made.
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Two cones joined at their bases are cut in half, and one half is twisted 90 degrees and put back together. Rolled on a desk, it is designed to use its whole surface and advance while swaying from side to side, so you can follow the path it takes with your eyes. Changing the number of sides of the cross-section and the twist angle gives versions with different paths.
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A set of three rods whose cross-sections are not circles but have the same width in every direction. A board placed on the rods and rolled is designed to stay at the same height, so you can feel the difference from a circle by hand. Three versions with 3, 5 and 7 corners can be made, plus an elliptical rod for comparison.
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A long boat-shaped top with a round bottom and a weight on the upper face placed slightly off the long axis. It is designed to spin one way, and when spun the other way to rattle, stop and then spin back (a phenomenon known as a rattleback). A mirror-image pair for left spin and right spin can be made.
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A looped string is passed through two holes near the center. After winding it up, pulling and loosening it with both hands makes the disc spin back and forth. The rim shape and cutouts are meant to change the sound of the air. Versions with a toothed, wavy or round rim, and with different numbers of cutouts, can be made.
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A rubber band is passed through a spool with two toothed flanges, twisted by turning a stick, then set on a desk. It is designed to crawl forward as the band unwinds. The way the flange teeth bite changes how it moves. Versions with sawtooth, round or star-shaped teeth, or with a different flange diameter, can be made.
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A small body hangs from a crossbar with string passed through two holes angled in a V shape. Pulling the left and right strings alternately is designed to make the angled holes catch the string so the body climbs bit by bit, and to slide down when loosened. The body can be made in shapes such as a triangle, hexagon, teardrop or arrowhead.
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Press the thin leaf-spring tail extending back from the body against a desk with a finger, slide the finger off and release, and the body is designed to hop with the returning force. You play by testing which way it jumps. Three versions with different tail length, thickness and curl, and so different hops, can be made.
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Each square tile has a gear in the center, and joining tiles with the tabs on their edges is designed to mesh them with the neighboring gears. Turn one and all of them turn in alternating directions, so you can rearrange the layout and watch the motion. Tiles with different patterns on the gear ring or different tooth shapes can be made.
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A car with the wheel holes offset from the center and mounted half a turn apart on the front and rear axles. Pushed by hand, the body is designed to move forward rocking up and down and back and forth, so you can enjoy watching the wobbly motion. Versions with eccentric circle, ellipse, rounded triangle or rounded square wheels can be made.
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The edges of polygon plates snap together to form hinges that can be folded. Each edge has round-rod bridges and C-shaped claws that grip them, alternating, so you can make strips or fold solids and keep adding pieces to make them larger. Variations with triangles, squares, pentagons and other shapes, and with different face patterns, can be made.
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Blades are stacked on a post on the base. Turning the top one is designed to make the lower tiers follow in turn, slightly behind. A tab on each tier enters an arc-shaped slot in the next tier and carries it along after a delay equal to the slot length, so the whole stack opens like a spiral staircase. Variations with different blade shapes and delay angles can be made.
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Turning the handle is designed to make a row of pins look as if it is rising and falling in a wave. About ten eccentric discs, each shifted slightly in angle, are threaded on a cross shaft, and the pins resting on the discs are lifted at a different timing, one by one, inside holes in the top plate. It is a desk piece for turning slowly and watching the wave flow.
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Turning the crank on the base is designed to make the left and right wings flap up and down. The rotation becomes the up-and-down motion of a push rod, which lifts the base of the wings pinned at a pivot on the post. Toothpick pins are used at the joints. The wings can be changed to straight, curved or cut-out shapes to enjoy how the flapping looks.
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Pushing a cone-shaped piece up from below through the stem tube is designed to open the petals outward. The cone spreads the base of the petals, and when you let go and lower the piece the petals close under their own weight. Changing the number of petals to 5, 6 or 8, or changing their shape, gives different flowers.
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Marbles are rolled down a slanted board, and you read the number you dropped in as a binary number. Each time a marble hits a T-shaped switch plate, the plate flips left or right, and the positions of three switch plates in a row show a number from 0 to 7. Drop the marbles in one at a time and see the count carry over.
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Turning the handle rotates a disc that lifts marbles, which then roll back down a chute. Notches in the rim of the disc scoop up a marble at the bottom, carry it to the top and drop it, and it returns to its start along a single return chute. A leaf-spring pawl rests on the teeth, so turning it is meant to produce a clicking sound.
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Put marbles in the cells of a wheel and turn it, and the marbles roll around inside, are designed to clatter, and eventually stop. One marble goes into each cell, divided by curved partitions, and the wheel hangs on the axle of a peaked stand. It is a model to watch, including the fact that it does not turn forever. Partitions in arc, straight and S shapes can be compared.
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Nine pendulums of slightly different lengths are released at the same time, and you watch how the line changes. Because the periods differ, a row that was lined up like a wave is meant to scatter and then line up again. A comb-shaped board lets you release them all at once, and washers serve as the pendulum weights.
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A small plate with keyhole-shaped notches at both ends is designed to tumble head over heels down a ladder. Hung on the top rung, it turns half a turn around the rung and catches on the next one, and continues clattering to the bottom. One ladder takes several plates, so you can race them, changing the plate shapes, colors and notch shapes.
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A ring on a twisted three-lobed rod is designed to come down while spinning. The ring has a hole of the same shape as the rod and turns under its own weight as it descends, and when you flip the rod over it starts down again. A series is possible with ring outlines such as a star, flower, gear shape or feather, and with different twist directions and strengths.
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Turning the handle is designed to make the pattern on a twisted column look as if it keeps flowing upward. Two pin gears, one on a horizontal shaft and one on a vertical shaft, mesh at a right angle and turn the column on top of the vertical shaft. The column cross-section can be a triangle, square or star, and the twist strength can be changed, for different looks.
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A palm-sized ratchet in which a knob turns a nine-tooth wheel against eight flexible claws arranged inside an outer ring. Because the claw and tooth counts differ by one, it is designed so that the position where a claw is flicked moves from one neighbor to the next around the ring. Variations with other pairs of claw and tooth counts can be made.
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Six slots of different lengths are cut in a plate about 34 mm square, with one piece in each slot. Tilting the plate from side to side is meant to set all the pieces sliding at once and hit the ends in order from the shortest slot, stopping like a staircase. Variations with a different order of slot lengths can be made.
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A rolled chain of 10 short links. Hold the rolled end and flick it out, and the links are designed to knock against each other in turn as it unrolls into a single bar. On one side it does not bend past straight, and on the other it bends to a set angle and can be rolled into a spiral. Changing the bending angle changes the rolled shape.
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Pinch the handle and shake, and the plates on both sides, joined by thin necks, swing with a delay and are designed to strike the center plate alternately from the front and the back. A one-piece palm-sized print that is aimed at a clapping sound. Variations with different plate outlines or a different number of plates can be made.
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Square frames are joined with a half-pitch offset to make a mesh about 110 mm square. Held in the hand, gripped or hung, it is designed to flow and change shape like cloth because of the play between frames, and is meant to make a jingling sound. Versions with different frame sizes and thicknesses can also be made.
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A drum with 12 small plates set between two discs, turned by a handle. A plate that comes to the top catches on a stop pawl on the base and stands up, and once past the pawl it is designed to fall forward one plate at a time. Changing the number of plates or the surface pattern changes how it looks while turning.
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Pins on a hand-cranked drum push and release the tips of seven comb teeth of different lengths one at a time, and it is meant to make a plinking sound. Swapping in a drum with a different pin layout changes the order in which the teeth are plucked.
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A flip board about 160 mm tall: a back plate with staggered pins holds a few washers and is closed with a lattice front frame. Turn it upside down and the washers are designed to fall, bumping into the pins and being sorted left and right, and it can be repeated with each flip. A version with a different pin layout can also be made.
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A desk piece for watching an escapement. A wheel that tries to turn under a weight on a string is stopped and released one pin at a time, alternately, by two pallets joined to a pendulum. The wheel is designed to advance one pin with each swing of the pendulum. You assemble it with a round rod, string and a coin.
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A blade is mounted on a small screw axle at the end of a rod about 180 mm long with a row of peak-shaped notches along one side. Rubbing the notches back and forth with a separate rubbing stick passes the vibration to the blade, which starts to turn and is meant to make a rasping sound. Versions with a different blade shape or finer notches can be made.
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A seesaw-style design: five small hammers are set radially on a disc about 110 mm in diameter, and the string from each hammer gathers at one weight below. Hold the disc level and swing it in small circles, and the hammer heads are designed to strike the disc in turn, starting with the hammer whose string is taut. Versions with a different number of hammers or head shapes can also be made.
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Twenty thin small plates are threaded on two strings, with both ends tied to handles. Hold the handles in both hands and flick one end, and the plates are meant to tilt while knocking against their neighbors in turn, sending a wave from one end to the other. Versions with a different number of plates or outlines can also be made.
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