Models Showcase: free 3D-printable organizers

By Krypto

Complexity

Medium

Others Kids & play

0

MAIN PURPOSE: Excavate buried finds square by square on a string grid, like a real dig

Real archaeologists never just dig: they lay a grid of strings over the site and record every find by its square and layer. Bury small treasures in layers of sand and soil, tie string through the eight holes to make a 3 x 3 grid, and dig one square at a time with a spoon and a paintbrush. Columns A to C and rows 1 to 3 are marked on the sides, so a find goes in the notebook as "B2, layer 1, a bone button". It teaches patience and why the position of a find matters as much as the find.

Printing notes

97.3 cm³

Volume

120.7 g

Est. weight

7,212

Triangles

Thread two strings each way through the holes for a 3 x 3 grid. Bury finds in layers of sand, soil and gravel. Prints as shown on its floor, no supports.

AR view Open in app

By Krypto

Complexity

Advanced

Others Science & education

0

Junior forensic lab

MAIN PURPOSE: Dust and match fingerprints and unmask a pen with ink chromatography

Two classic detective techniques in one tray. Dust a glass with cocoa, lift the print with clear tape, stick it on a card and compare it with the ARCH, LOOP and WHORL patterns engraved in the bays. Then solve the mystery note: dot ink from each suspect's black pen near the bottom of coffee-filter strips, hang them from a skewer across the INK trough with their tips in water, and watch each ink split into its own bands of colour. The pen whose colours match the note is the culprit.

Printing notes

102.9 cm³

Volume

127.6 g

Est. weight

10,320

Triangles

Use cocoa or pencil graphite as dusting powder and clear tape to lift prints. Coffee-filter strips work for the chromatography. Prints as shown on its floor, no supports.

AR view Open in app

By Krypto

Complexity

Multi-part assembly

Others Kids & play

0

Scytale cipher tube

MAIN PURPOSE: Send secret messages that only a tube of exactly the same width can read

The Spartans sent secret orders 2,500 years ago with a scytale. Wind a narrow strip of paper in a spiral round the tube, write your message along it, one letter per turn, then unwind it: the letters scatter into nonsense. Only someone with a tube of exactly the same width can wind it back up and read it. The flat faces of this hexagonal tube keep the lines of writing straight, and the strip lives inside it under the screw cap. Change the width before you print and your pair of tubes becomes your own unbreakable key.

Printing notes

96.4 cm³

Volume

119.6 g

Est. weight

2,844

Triangles

Print two identical tubes, one for each friend. The diameter is the key: change the width to make your own private cipher. Prints as shown on its floor, no supports. The threaded lid and its neck piece print separately; adjust Fit in the Lid tab if it binds.

AR view Open in app

By Krypto

Complexity

Medium

Others Crafts & making

0

Harmonograph sand pendulum

MAIN PURPOSE: Draw looping Lissajous patterns with a swinging cup of sand

Hang this cup from a Y-shaped string: two strings tied to two hooks that join into one about halfway down. The Y lets it swing at one rate side to side and a different rate front to back, so as it swings and slowly dies down the thin stream of sand traces loops, figure-eights and spirograph flowers on the card underneath. Move the knot higher or lower to change the ratio and the drawing. It is the Victorian harmonograph, made with a cup, a string and a bag of sand.

Printing notes

9.8 cm³

Volume

12.1 g

Est. weight

1,816

Triangles

Fill with fine dry sand or salt and hang it from a Y of string about 1 m long over dark card. Tape over the bottom hole until you let go. Prints as shown on its floor, no supports.

AR view Open in app

By Krypto

Complexity

Medium

Others Garden & plants

0

Do-I-water planter

MAIN PURPOSE: Grow herbs in a planter whose own rain gauge tells you whether to water

Should I water today? This planter answers by itself. A straight-sided rain gauge is built into its side: because the tube is the same width all the way down, every millimetre of water in it is a millimetre of rain. Check it when you pass. Less than 10 mm since you last emptied it, and the pot needs a drink; over 25 mm, the rain has done the job. It stops the most common way of killing outdoor herbs, which is watering after it has already rained.

Printing notes

50.9 cm³

Volume

63.2 g

Est. weight

7,800

Triangles

PETG for outdoors. Empty the gauge every Sunday. Under 10 mm in a week means water; over 25 mm means skip it. Prints as shown on its floor, no supports.

AR view Open in app

By Krypto

Complexity

Simple

Others Kids & play

0

Vortex air cannon

MAIN PURPOSE: Fire invisible rings of air across a room to knock over paper cups

Tap the stretchy top of this box and a spinning doughnut of air shoots out of the round hole in the side, holds together across the room and knocks over a paper cup or blows out a candle three metres away. It is a vortex ring, the same thing as a smoke ring or a dolphin's bubble ring. Fill the box with mist from a humidifier or incense (with an adult) and you can see the rings wobble through the air.

Printing notes

87.5 cm³

Volume

108.6 g

Est. weight

3,080

Triangles

Stretch a cut balloon, shower cap or plastic bag drum-tight over the open top and tape it all round. Tap the middle sharply. Prints as shown on its floor, no supports. Large holes in the walls may need supports or good bridging.

AR view Open in app

By Krypto

Complexity

Advanced

Others Music & audio

0

Windowsill Aeolian harp

MAIN PURPOSE: Let the wind play an eerie chord on strings stretched over a sound box in an open window

The Aeolian harp was a Romantic-era wonder: a box of strings placed in a half-open sash window that the draught plays by itself. Wind passing over a string makes it vibrate in shimmering overtones, rising and falling with the gusts, a sound Coleridge wrote a poem about. String this sound box with fishing line over its two bridges, all tuned to one low note, and lay it across an open window. On a breezy day it sings a ghostly chord without anyone touching it.

Printing notes

95.1 cm³

Volume

117.9 g

Est. weight

4,472

Triangles

Thread three to five fishing lines (0.3-0.8 mm) through the end holes, over the two bridges, and tie them off; tune them all to the same low note. Prints as shown on its floor, no supports. Stacked parts are fused into one print.

AR view Open in app

By Krypto

Complexity

Medium

Others Photography & film

0

Stop-motion animation stage

MAIN PURPOSE: Animate clay figures frame by frame with a phone locked in front of a mini stage

The secret of smooth stop-motion is a camera that never moves. The phone slots upright at the front of this three-walled stage and stays perfectly still while you move a clay figure a hair at a time between frames. Twelve photos make one second of animation. Tape a printed background to the back wall, add a desk lamp from the side, and you have a little film studio for clay, toy figures or paper cut-outs.

Printing notes

132.0 cm³

Volume

163.7 g

Est. weight

5,242

Triangles

Slide the phone into the slot, camera facing the stage. A free stop-motion app shows the last frame as a ghost to line up the next. Prints as shown on its floor, no supports.

AR view Open in app

By Krypto

Complexity

Simple

Others Crafts & making

0

Tie-dye spiral plate

MAIN PURPOSE: Twist a T-shirt into a spiral and dye six clean colour wedges on a ribbed plate

The classic tie-dye spiral needs the shirt twisted into a flat disc and squirted with one colour per wedge, which usually happens on a soggy bin bag. This plate makes it tidy. Twist the damp shirt round a fork in the centre, then lay it so the six low ribs underneath line up with your rubber bands: each wedge gets its own colour, the ribs keep the dyes from running into each other underneath, and the rim catches the drips. Unwrap it next day to a crisp six-colour spiral.

Printing notes

115.8 cm³

Volume

143.6 g

Est. weight

4,456

Triangles

PETG; wipe dye off straight away. Twist the damp shirt flat round a fork in the centre circle, band it into six wedges along the ribs. Prints as shown on its floor, no supports.

AR view Open in app

By Krypto

Complexity

Advanced

Kitchen Food preparation

0

Spherification caviar kit

MAIN PURPOSE: Make bursting pearls of juice by dripping alginate into a calcium bath

In 2003 the elBulli kitchen discovered spherification: drip juice mixed with a little alginate (from seaweed) into a calcium bath, and each drop instantly grows a thin jelly skin while staying liquid inside. Load the syringes standing in the rack, drip mango, balsamic or cola into the BATH, lift the pearls into the RINSE, then spoon them into the SERVE bay. They pop on the tongue like caviar, a bit of modernist cooking for any home kitchen.

Printing notes

82.8 cm³

Volume

102.7 g

Est. weight

10,400

Triangles

Food-safe PETG. Blend 1 g sodium alginate into 200 ml juice and dissolve 2.5 g calcium chloride in 500 ml water. Prints as shown on its floor, no supports.

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