3D Printed Construction Toy

Render: a single cube and connector with some fancy lighting.

I played with some other 3D-printable construction toys and wanted to have a go at designing my own variation.

Other projects I looked at:

PrintABlok (https://www.printables.com)
STEMFIE (https://www.stemfie.org)

Something else I can't remember the name of
...there are so many of this sort of thing!

I liked PrintABlok's simplicity, easy of printing, ability to join blocks along any axis, and inclusion of decorative parts.
Many of these projects seem to focused more on prototyping, which is perfectly reasonable, but building spaceships appeals to my nostalgia!

The two weaknesses I found with PrintABlok were a tendency to wobble and come disconnected, and the opposite, a tendency for connectors to get stuck and need pliers to remove.
In the end, my design seems to avoid the wobbling (if you tweak the print parameters enough), but can be pretty difficult to take apart.
My design also require some supports, which is annoying, though they're fairly easy to remove.

Render: a spaceship made of various different blocks.

Parts

The parts are grouped into these collections:

• basics: basic solid parts (single cube, Nx1x1 long pieces, NxNx1 flat pieces)
• dealigned: non-integral size joining pieces
• detailed-cap: decorative 1x1x1 end pieces (rocket engine, fin, propeller, solar panel)
• edges: smooth corner/edge pieces (diagonal, round)
• motion: moving hinges
• partial: assorted oddly-shaped joining and cap pieces
• plates: experiment in decorative flat pieces, I would recommend the texture pieces instead
• texture: decorative flat plates (port hole, pipes, stripes, smooth)

STL files
OpenSCAD source files

Printing Parameters

I can't remember exactly how I set up printing, but the basic setup I used in Slic3r was like this:

• PLA filament
• layer height: 0.2mm
• nozzle diameter: 0.4mm
• gap fill: off (saves retractions and resulting string on connectors)
• detect thin walls: off (avoids adding thin extra bits to connecting faces)
• support: off (some supports are included in the parts)

Part files are in print orientation (Z axis is up) and include supports where required.

The main issue I ran into was the top and bottom of the joining parts of cubes, which forms a sharp 45 degree edge, ending up with a brittle single-width wall on the top and bottom.
This made them too wide until the extra wall snaps off, after which they're too thin.
I think the setting above solve this, but tweaking may be needed.

Render: four iterations of my connector design, including the finished one.