### My adventures in 3D printing: Golomb ruler

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

At the start of the Summer we (I) bought a new 3D printer for the department, a FlashForge Dreamer. It’s got two extruder heads, so it can do two-colour prints.

To test that out, I designed this Golomb ruler. It’s a straightedge with marks at 0, 1, 4 and 6 cm. The idea is that you can measure 1, 2, 3, 4, 5 or 6 cm by lining up against different pairs of marks. I recently did a silly Twitter thread on this subject.

As you can see from the photo, two-colour printing isn’t quite as straightforwared as it could be. Because both nozzles need to stay hot, while one colour was printing the other just oozed out and made a mess. There are some settings on the printer you can change to try to reduce this, but I haven’t got the hang of it yet.

### My adventures in 3D printing: Wallis’ Sheldonian theatre roof

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

The roof of the Sheldonian theatre in Oxford, built from 1664 to 1669, is constructed from timber beams which are unsupported apart from at the walls, and held together only by gravity.

### My adventures in 3D printing: Spherical pseudo-cuboctahedron

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

This shape is a “spherical pseudo-cuboctahedron”, prompted by a request from Jim Propp on the math-fun mailing list.

It has 24 vertices, 12 edges and 14 faces. That doesn’t satisfy Euler’s formula $V – E + F = 2$, so it can’t be a proper polyhedron – hence “pseudo-cuboctahedron”.

However, if you push all the vertices onto the surface of a sphere, all the edges are spherical arcs, it sort of works.

While designing this object, I got fed up with OpenSCAD‘s awkward control syntax, and switched to Python. I wrote Python code to produce the coordinates of points along the edges, which the SolidPython library turned into something that OpenSCAD can cut out of a sphere.

### My adventures in 3D printing: Write Angles Cube

At work we’ve got a 3D printer. In this series of posts I’ll share some of the designs I’ve made.

This is one of the first ‘proper’ things I’ve designed – I wanted to have a go at making something based on an object I already had. A colleague asked if I could make some props to explain coordinate systems, and I was holding a whiteboard pen at the time, so I decided to make a set of orthogonal axes out of whiteboard pens.

### TeXnique: a LaTeX typesetting game

You know what’s fun? Typesetting mathematics! Glad you agree, because here’s a game that puts the fun in ‘underfilled hbox’.

In TeXnique, you’re shown a typeset bit of mathematical notation, and have to frantically type LaTeX to reproduce it. You get three minutes, and you’re awarded points when you produce something that’s a pixel-perfect replica of the original. Think Typing of the Dead crossed with The Art of Computer Programming.

When I first saw this I rolled my eyes, but now my high score is 68 and I don’t know why I keep going back to it.

The formulas are largely well-known snippets of notation, so you might find some of them coming out through muscle memory, but if a symbol shows up that you can’t remember the macro for, there’s always the brilliant Detexify tool.

Play: texnique.xyz by Akshay Ravikumar.

### I’m streaming digits of π for π day

It’s π eve, and I’ve had a silly idea: I’m going to take the ridiculous website I made to show all the digits of π, and stream it scrolling indefinitely through them over the internet.

Starting at midnight GMT on 2019-03-14, the stream below will start scrolling down through the digits of π:

I had this idea this morning, and it’s running on my desktop PC which I’ll be away from until 8am tomorrow, so I won’t be surprised if something goes wrong.

But if it doesn’t: hooray!