May 28, 2023

3D Printering: Can You Ever Have Enough Vitamins?

As a community we owe perhaps more than we realise to the RepRap project. From it we get not only a set of open-source printer designs, but that 3D printing at our level has never become dominated by proprietary manufacturers in the way that for example paper printing is. The idea of a printer that can reproduce itself has never quite been fully realised though, because of what the RepRap community refer to as “vitamins“.

These are the mass-produced parts such as nuts, bolts, screws, and other parts which a RepRap printer can’t (yet) create for itself. It’s become a convenience among some of my friends to use this term in general for small pieces of hardware, which leads me to last week. I had a freshly printed prototype of one of my projects, and my hackerspace lacked the tiny self-tapping screws necessary for me to assemble it. Where oh where, was my plaintive cry, are the vitamins!

So my hackerspace is long on woodscrews for some reason, and short on machine screws and self-tappers. And threaded inserts for that matter, but for some reason it’s got a kit of springs. I’m going to have to make an AliExpress order to fix this, so the maybe I need you lot to help me. Just what vitamins does a a lone hardware hacker or a hackerspace need?

A good place to start this is at home. I have a big tub of those rattly plastic boxes, each containing a kit of some kind of hardware. Thinking through the stuff, it divides fairly neatly into three categories of threaded hardware, miscellaneous hardware, and consumables. In fact as I had a look in the box it surprised me just how many different items I had accumulated through years of tinkering.

In the threaded category are screws, nuts and bolts, and inserts. But screws and bolts start at the near-microscopic watchmakers’ level and progress to gigantic fixings that hold oil rigs and ships together, so it’s worth thinking about exactly what sizes to keep. In my case my loose distinctions are automotive nuts and bolts, and ones for the bench. I have only metric sizes, so perhaps above a 10 mm spanner or an M6 bolt starts to come into the automotive category, while below that is for the bench. I have kits of nuts and bolts and washers for the larger ones, with self-tapping screws and threaded inserts in addition to those at the smaller sizes. I don’t yet have a kit of stand-offs or of plastic nuts and bolts, but they’re both things I should have

Miscellaneous hardware is a much broader category, because it depends so much on what you do. I have a box of O rings, a tin of split pins, a kit of small springs, and a growing collection of battery contacts and curly springs for those corroded Duracell cases. I keep meaning to order a kit of belts to replace the random ones I’ve salvaged from equipment over the years, and there have been so many ping-sodit episodes over the years involving small circlips I should really be ordering a set of those too.

As you might imagine in the consumables box I have a load of cable ties. The German Lidl supermarket does kits in their aisle of wonders that have been issued in a range of bright colours over the years, so I’ve amassed enough to join anything together. I have heat-shrink tubing in a load of sizes in all colours of the rainbow, several kits of different crimp connectors and terminations, a box of assorted fuses, and all the shells and metal parts for several different types of multiway connector.

With all this variety there should be nothing I can’t do, but the reality is that this represents only a baseline. I know there will be more kits ordered through necessity rather than simply thinking I should have them. Perhaps it’s the last item in my stock of vitamins then that’s the most important. I have a tin that once contained Danish butter cookies, and into which for years I’ve thrown all the screws and other small hardware I remove when I dismantle something for its parts. It’s a glorious mess of small hardware, but such is its variety that sifting through it has saved my bacon many times.

Writing this has enabled me for the first time to sit down and think about what I have in the way of these vitamin parts, rather than in terms of single ones when I need something. It’s also made me think a little about what I should be buying to complete my collection, so I’ll probably be popping a few more of those rattly boxes on my next AliExpress order. Are there any I’ve missed? Please let me know in the comments!