3D-printed products and 3MF downloads from Roxium in Burlington, Ontario

Two spirals in one print: an outer shell that twists one way and a core that twists the other, turning past each other as you fiddle. Printed in a single colour it reads as one tapering cone; give the shell and the core a colour each and the two spirals separate in the eye as they turn, which is what the designer's own pictures show. The profile that prints it is 0.2 mm layers, 3 walls, 15 per cent gyroid infill, PLA, no supports, standing upright exactly as supplied.

Design by NerdHerder

An impossible passthrough built as a pyramid: the parts pass through one another and no amount of turning lets them go. 2.8" tall, about 21 g of plastic.

Design by BeninManc

An impossible passthrough shaped like an hourglass: two halves that turn through each other and stay locked together. 2.8" tall, about 24 g of plastic.

Design by BeninManc

A hard hat that goes on a keyring - the dome, the brim and the little ridge down the middle, printed in one piece with a hole through the top. 1.5" across, and it works as a key tag or a desk charm.

Design by astavr

A gyro fidget spinner: three curved rings interlock around a centre post and whirl as one, so it prints in a single piece with no bearings and no assembly - just flick it and go. The rings are loose in their track out of the printer, which is the part that takes a few tries to get right and the reason this one gets measured before it ships.

A squeezer that slides up the tube as it empties: the roller presses the paste forward and the key at the end hooks over a rail so the tube hangs. 2.9" long, printed in one piece with the edges rounded so it does not catch on the shelf. Remixed by Weisnetde from two earlier squeezers, all under the same licence. Shown as a render, not a photo.

Design by Weisnetde

A hexagonal tube cut into one continuous spiral, so it springs and flexes in the hand and the turns of the helix roll past each other under a thumb. It prints as a single piece and needs no assembly, and it stands 2.8" tall by 1.3" across. Shown as a render, not a photo.

Design by NerdHerder

A frog that jumps: press its back and it springs off the table, and the pond bowl catches it. Pick the frog on its own or the bowl with it - the bowl is 5" across, and three frogs fit on one plate if you want a set. Shown as a render, not a photo.

Design by Niski

A ruler that folds: nineteen 160 mm segments that hinge end to end, plus the two end caps, so it measures a room and then folds down to a pocket. The full set is 19 segments; the smaller option is the same design at 70 per cent, which is the one for a desk drawer. Shown as a render, not a photo.

Design by PenguinPrototypes