This project is an preliminary attempt at designing a flexible 3D construction kit. Ideally, the fully realized kit will be similar in spirit to legos... but more suited to modeling complex solid geometry.

So far, the kit has 2 primitives: a vertex and an edge. The vertex is a disk with 4 equally spaced notches cut into its edge. The edge has 2 rotating heads (one on each end) which are notched to slot into the vertex disk.

An easy way to increase the expressiveness of this kit would be to add vertex disks with 3 and 5 notches. Given those parts, one could make tetrahedra, cube, and dodecahedra models (3 notch vertex disks), as well as icosahedra models (5 notch vertex disks). The same edge primitives built in this kit could be reused.

The octahedron is the only platonic solid whose vertices terminate 4 edges, so that's it for this kit. To build the object, 6 vertices and 12 edges are required. The svg file has 16 edges and 16 vertices.

Materials:

1. 3/16 inch diameter dowel rod (preferably a soft wood like pine).
2. Hack saw (or other fine-bladed hand saw).
3. Very rough sand paper.
4. Very fine sand paper.
5. 1/8 inch thick wood (for the laser cutter).

Instructions:

1. Before laser cutting, you will need to rescale the svg and otherwise clean it up. Make sure that the width of the long edge pieces is 1.4 cm.
2. Assemble the edges. Each edge is made of 2 long pieces (they have two holes) and 2 heads (shorter, one round hole, and a rectangular notch for slotting into the vertex).
3. Twist the dowel into one of the long edge piece holes. With a little elbow grease, it will slowly go in as you continue rotating it and applying pressure.
4. Add an edge head, and continue twisting the dowel through that as well. Then add a second long edge piece. You will now have the dowel twisted through 3 pieces (which are sandwiched on top of each other).
5. Use the hack saw to cut off the extra dowel.
6. Repeat with the head on the edge's other end.
7. Use the coarse sand paper to smooth the dowel ends (or to remove excessive material).
8. Once all the edges are done, use the fine sandpaper to sand inside the vertex notches / edge head notches. Only a very small amount of material needs to be removed. For best results, smooth out the inner notch point, so that the notch outline curves slightly outward.