Cubie. 3D-printable toy editor

My daughter got a 3D printer. The first thing you do with one is print something, and the slicer app ships with its own catalog: phone stands, anime keychains, dinosaur skulls, all ready to click and print. It's satisfying for about an afternoon.

Then the catch becomes clear: nobody actually made anything. Between marketplaces of pre-baked meshes and generative AI tools, the hands-on act of inventing a physical object quietly slipped out of the picture.

I went looking for a tool that would let someone start from a blank slate — without CAD training, without understanding tolerances or mechanical joints — and hold a toy they designed themselves by dinner. It didn't exist.

Kids already know how to model in three dimensions — they do it every day in Minecraft. Cubie builds on that same voxel instinct: you place cubes directly into a 3D scene, carve out volumes, and paint surfaces.

There are three ways to work: Sketch mode on a flat grid, layer-by-layer for structured vertical builds, and a first-person fly-through where you place blocks in mid-air — creative mode, with an export button at the end of it.

When the voxel shape is finished, you switch to Assembly. Cubie scans where parts meet, detects the contact planes, and cuts the model into separate pieces with snap-fit ball joints embedded between them. From there, you export directly to 3MF or STL for standard FDM printing.

In the editor, every connection stays interactive: rotate a shoulder, bend an arm, or flex a limb to test how the toy will move before printing it. And for solid figures, joints can simply be turned off.

As the editor grew, new parts kept arriving: springs, chain links, wheels you could resize interactively, and limbs — arms, legs, sneaker feet, robot legs, paws. With every new feature, the interface started crowding the 3D model.

Four times in a single week I tore down the desktop layout and rebuilt it. I moved the action buttons around and tested them continuously: trying them across the top, down the side, and in compact floating trays. The rule was that primary actions had to stay immediately visible and accessible, without encroaching on the model itself. To make it work, I added text labels beside the icons, tightened the controls, and added animated previews for the joints so you can see how each connection behaves before placing it.

Mobile needed a completely different structure. Rather than shrinking the desktop controls onto a phone, I moved all tool actions into a horizontal bottom ribbon you can sweep through with a thumb — leaving the canvas clear above.

A separate pass went into texture: reliefs — studs, domes, bumps — and counter-reliefs — recesses, slots, honeycomb — that stamp onto any face of a cube. The point isn't decoration. A plain plastic block doesn't ask to be picked up. One with texture does.

You'll run into some. Cubie reached the point where shipping it and hearing from actual people teaches more than another month of polishing alone. I'm working through them as they turn up.