How can I select generically re-usable parts for the unique things I build?
What are good approaches for building unique devices, so that when I no longer need them,
it's relatively easy to disassemble them into parts I can re-use on the next project?
This question focuses on when I build one or a few physical objects.
The "design for disassembly" techniques used in some sustainable designs may also be related, although that focuses more on physical objects built in larger quantities — is there another question that focuses on that?
Reusing abstract designs for hardware is already covered in another question.
There are lots of items I build exactly one of:
the first (or the 17th) breadboarded prototype of the electronics of a product;
various unique templates and jigs used in production;
test jigs, etc.
When they reach the end of their useful life, they get tossed in the scrap box.
I build them out of
(a) random scrap still hanging around from previous projects, and
(b) new stuff we got with (perhaps shortsighted) focus on this particular project.
I can't help but notice that the shiny new stuff ends up in 3 categories:
- a Some things — solderless breadboards, soldering iron, 1/2 inch (12 mm) socket wrench, pin headers on 1/10 inch centers, alligator clips, velcro cable-ties, etc. — get re-used over and over again.
- b Some things that at first glance appear very similar — 15/16 inch socket wrench, etc. — only get used for one job, and are never used again. While those things were necessary for that one job, and so perhaps I should think of them as a "sunk cost" that I've already made back the return on their investment. Since they are still functional, it seems wasteful to simply throw them away. So they end up taking up space and collecting dust indefinitely.
- c Some things can only be used once — zip ties, solder, etc. Sometimes it seems a little wasteful, but (if I maintain a short-sighted focus on this particular project) these disposable items are the cheapest way to get things done, and at least they don't tend to accumulate and take up space.
Category (b) is the worst.
If I knew at the time I was buying that part what I know now after watching that part collect dust for years, I would have either saved a little money and bought some disposable category (c) part instead, or else spend a little more money and bought some more generally useful category (a) part instead.
(Or perhaps not. Sometimes I absolutely need some super-specialized part for some project).
Do you have any tips for recognizing ahead of time that a part I am about to buy is highly likely to end up gathering dust as type (b), so that I can try to substitute something that is more likely to be type (a) or type (c)?
Any other tips for making it more likely that parts and tools I hope to re-use actually are re-used later?
Rather than make one all-singing, all-dancing do-everything hyper-specialized PCB that I'll only use this one time and then toss the whole thing, are there good ways to partition the design so that at least part of it is re-usable later?
What are good ways to improve physical hardware reuse?
Forget category c: some things are truly disposable and can't be reused in their current state unless you want to start a recycling company.
Category B is the most interesting. For tools, there's eBay: just resell stuff you don't need. Even then, a lot of what we do is specialty stuff: I have 6805J programmers that no one wants even for the cost of shipping. They've simply outlasted their usefulness.
The problem with reusing hardware is the documentation has to be perfect, or the time spent trying to reuse a board or other hardware becomes more costly than simply starting from scratch again. I find that for the things I build for other people, I'm pretty good at keeping good documents. But for stuff I build intending to use for few days and then forget about, documentation is pretty much none existent, so boards end up permanently consigned to the junk bin.