I've made a video of my 3D-printed bolt and nut combination, showing the action of threading it on and off.

Although most of my novice experiments in 3D-printing have been just that, experiments intended to familiarize myself with the technology and its benefits and limitations, I have already had the opportunity to design and print something actually useful. Like most refrigerators, mine has storage areas on the door where items are secured by a removable or adjustable rail, keeping the mustard from flying when you yank the door open. These rails are hollow aluminum sections that accept plastic friction-fitted end caps, which in turn have hooks that engage slots on the door. One of the hooks broke off and naturally fell inside the door, so fixing it with glue was out of the question.

Original right-hand end cap with missing hook, next to intact left-hand end cap

I've been playing with a 3d printer lately, specifically a Solidoodle machine that deposits ABS plastic filament. As part of a larger project I've been designing various mechanical parts, challenging myself to do without support structures and keeping manual finishing steps to a minimum. One of the things I've tried to make is an entirely printed, functional screw thread, for both male and female parts. The result is the nut and bolt combination documented here.

As for the larger project, I'll publish more about that here soon, so keep visiting!

I believe strongly in publishing negative results, so I've written an account of an old project (December 2006), in which I tried and failed to build a solder fume extracting and filtering machine and learned some useful lessons along the way.

Six years ago I walked into an Army-Navy surplus store and bought a pair of Hi-Tec hiking boots for something like 30 dollars. They're sturdy and very comfortable, have given me good service in all sorts of places and conditions, and are likely to keep doing so for years to come. The laces, however, were beginning to show their age and experience; the anglets had come off and the inner core of the laces had retreated into the outer sheath. I had an opportunity, therefore, to replace them with a much stronger and more useful type of bootlace: mil-spec 550 parachute cord.

Black never goes out of style

This fits into the trend of survival experts and EDC enthusiasts carrying miles of paracord on their persons at all times, usually by tightly weaving it into something like a watch band or key chain. I'm impressed by their techniques but I'm far from being a serious student of wilderness survival—I only sniff around the edges of that community—but I enjoy hiking now and again and I'm very much a fan of preparedness and capability in all aspects of life.