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 pinecone geocache: a hollow cone with a screw-on cap and a loop at the top for a string or a length of wire, so it can hang in a branch. It prints in two pieces and neither needs supports. For a cache that lives outdoors, PETG keeps its shape in a hot car or a sunny hedge better than PLA. Designed by Soalar, who remixed it from Izak02's Pine cone cache - both makers are credited on this page. Printed under Creative Commons Attribution 4.0 (CC BY 4.0). Shown as a render of the printable model, not a photograph.

Design by Soalar

An arrow holder that takes up to twelve arrows, for shafts up to 11/32 of an inch across. One arrow or a dozen loaded on the same side, it stays upright, and it needs no supports; the designer printed his on an A1 mini. It is not a frugal print - the designer says so himself - so it is priced by what it weighs rather than by the pose. Designed by StickMan and printed under Creative Commons Attribution-ShareAlike 4.0 (CC BY-SA 4.0). Shown as a render of the printable model, not a photograph.

Design by StickMan

A pocket divot tool with a ball marker that sits in the handle: the fork lifts the green back into shape, the marker pops out to mark your line. 2.7" long, printed as two pieces. Shown as a render, not a photo.

Design by bitclicker

A hook remover with a forked end for backing a hook out and a flat end for pushing it through - the tool that means you do not put your fingers near the point. 4.8" long, printed flat in one piece. Shown as a render, not a photo.

Design by eclien