Steve's Design Blog: October 2023

Tetrahedron in process

6mm dowel pieces, 75mm long.

Modular dice which are available from Thingiverse here . I had been thinking for a while of how to make other dice sides - a pentagonal side for a dodecahedron, and triangular / adjustable angle sides for octahedron, tetrahedron and icosahedron.

Makittoy, I got the idea of using 6mm dowel from this.

Photo frame 2023 obverse

Photo frame 2023 (With Mary at Fairfield Ampitheatre). The inspitation came

Photo frame 2017 (Richard, Cicely, Sarah)

Finished! At the bottom is the raft from the 3d printing.

CD-Matic MKI with makittoy. These centre bits were a bit weak and broke eventually.

CD Matic MKI with Makittoy

Lamp Centre

Cd Matic mark II with 3d printed parts replacing Makittoy parts.

Today I started working on a "Universal Polyhedron Kit" and have finished making the basic parts and putting them to use. The above pics are a bit jumbled, but I hope you can make sense of them. Prior to this I have made lampshade parts, Cd-matics, and modular dice, and the ideas have eventually rolled together to make this one.

The kit currently consists of 3 pieces, use 6mm dowel, and I have made a tetrahedron from them. The kit is male and female hinge halves, which are a bit like rod ends . The hinges join rods together to form polygons. The polygons can then go on to make polyhedra with the help of the spacer part. All the other platonic solids can be made (in twin edged form) from the 3 parts and 6mm rod. The hinge halves add 15mm to each end of the dowel rod.

Now on thingiverse! Here!

Update, 25/10/23

Overnight, I designed and printed some new parts, a "switch" for the Universal Polyhedron Kit. This creates links between 2 parallel edge pieces, allowing joining of polyhedra sides. In the example pics below, I have highlighted the 2 sets of triangles in blue and orange joiners. The ideas for this came from my work with basket cane, making twin edge polyhedra in spherical form. The draft writeup for the cane constructions is here , and I've included a diagram about switch placement below. It should be fairly easy to make a model from a continuous set of rods, this needs 3 switches in the tetrahedron.

Update October 27, 2023

By yesterday morning I had enough bits printed to make something besides tetrahedrons and was thinking of a cube with 2 sets of sides. I'd also walked to the local hardware shop (Demars) and bought some locally made (Porta) 6mm timber dowel rod.

Then I worked out I could make a vase stand for a mug I have. On a morning trip, I bought a small $8 glass vase from an op shop. The existing triangles I had were the right size for the new vase. I had a go at calculating the size for the bigger triangle at the other end, but in the end there was some trial and error to make it right. The vase support is divided into orange and blue sides. Photos below, a good result I think.

Update, 2/11/2022 (The male is redundant, lesbians you are right)

After a while I realised that the only piece of the kit that is really needed is the female rod end as per the pic below. "2 blue female parts can take the place of the red rod joiner and the orange male / female hinge assembly." "The male of the species is almost entirely redundant".

To make a cube using the techniques shown above - including extending a hinge pin to make an edge - requires fewer pieces, ie only 16 3d printed parts and 12 rods, as shown below in 3d cad.

Update Nov 23. In the last week I've made all the platonic solids from the kit, and pics are below. Mary and I used the icosahedron for deportment practice - hilarious!