It’s been a bit over a year since I published a blog post, just because I’ve generally been busy with things that don’t seem very bloggable (sidenote: that’s a real word).

I’ve generally considered blogging to be a tool for keeping family and friends updated on what I’m up to, or for sharing bits of information that someone (including future-me) might find useful. Over the last year or so, my projects outside work have largely related to open source software development and there hasn’t been a lot of information that isn’t already published online. Family and friends don’t seem to get much enjoyment out of code snippets, CAD screenshots, or development anecdotes; hence, no blog.

Recently though, I’ve been doing more hardware work and have realised that a blog might make a good index in to the raw design files/source code/etcetera that comprise hardware projects. Essentially, I think that a blog might also be a good way tool for providing context for the sort of raw ingredients that I’d like to share.

So, what projects are on-the-go lately?

Rewinding Accutron Coils

One of the most clever and elegant pieces of engineering I’ve come across is the “tuning fork” watch movement, exemplified by the Bulova Accutron 214. Rob Berkavicius has an excellent website about Accutrons, or google has plenty pictures.

How I got started is a long story, but I’ve spent much of the last several months working out how to re-wind the coils used in the Accutron 214s. There are a number of interesting challenges involved, mainly centred around the 54 AWG magnet wire the coils are wound with - that’s 15 micron in diameter, about a quarter of a hair. Spider silk is about the best commonly understood simile; I’m making coils with several thousand turns of spider-silk-size magnet wire.

At this stage, I can wind coils that seem to work fine in a watch, with only a small modification from the original design. I’ll hopefully be able to make them without the modification soon, but need to re-make part of my winding machine first.

One of these days, I’d like to make an animation that shows the movement working, both in terms of the mechanical motion and the electronics.

BoardBot

This is another random project - I’ll make a longer post about it later. The basic idea is that it’s a simple robot that draws on a whiteboard, and can be controlled by Scratch. I think it might be interesting in a grade school educational setting.

I think there are basically two aspects to “learning to code” that are difficult, much like the essence and accident as described by Fred Brooks. Scratch does a great job at attacking the accident, by removing most of the syntactical tedium, and is a lot of fun too! It seems to me that robotics might be good for attacking the essence, by providing a real-world reflection of the computer program to help motivate the “why” in programming.

All the parts outside the electronics are 3D printable, so building it can be as much of a project as learning to make it do fun stuff!

FreeCAD

My last blog involved work on FreeCAD, an open source CAD program mainly aimed at mechanical work. I’ve continued to work on FreeCAD, mainly on the new TechDraw module (it outputs traditional paper-type drawings of 3D objects), but also a bit on packaging up FreeCAD dependencies for MacPorts and Homebrew.