As great as a tight Hardinge HLV lathe or Mantis Elite microscope is, they're not things that will pay for themselves quickly in most of our hands. The tools I'm about to list are much more likely to carry their own weight, and incidentally are not too hard to carry.
In no order:
Grobet Vul-Crylic file: I asked my dad where "The good rasp" was, with no other words, and he knew I was talking about this one of the dozen we have. If I could have just one file, this would be it. It's not too expensive either, and it comes in different lengths. It saves a lot of sandpaper, is faster and cleaner, and is more pleasant to use.
Bandsaw: It's quick, efficient, safe, versatile, pleasant, and elegant. It uses the incredible properties of tool steel for the blade, and pushes them all right to the functional limit. The flat blade pulleys are very efficient; little energy is wasted churning bearings or flexing belts. The results speak for themselves. Perfection in design, and why it hasn't changed in a century or two.
We get caught up in tolerances and precision, which is probably denial about our sloppy state of existence. Living things change shape and form constantly; we are not exempt because we figured out how to measure with lasers. The lasers certainly aren't perfect either. The wisest know just how accurate something needs to be. I think it follows that the wisest aren't afraid of a bandsaw blade wandering off course .020". It's looking reality in the eyes and greeting it with a firm handshake.
.020" blade drift is good enough for my own furniture, for my helmet visor, for a boat keel or an airplane spar. For window trim, a server rack, a steel wrench, or a shoe sole. A 3d printer or CNC router might be accurate to .001", but it can't make any of those things with a straight face like a bandsaw can. Or a thousand others, for that matter.
I want to make Mathias Wandel's brilliant wooden one sometime, though we've already got two so it won't happen soon.
Taig Lathe: I curse at this machine a lot, although I shouldn't. Compared to having parts made at a machine shop, it has probably paid for itself a hundred times over. A very useful minimum set up is:
-The four jaw chuck, nothing else for workholding. If you're machining you probably need a dial indicator anyway, but it's not a necessity.
-Almost any motor will do, but it the lathe is SO much more useful if it can spin below 300 rpm
-Quality HSS tool bits. A bench grinder is not absolutely necessary. You can use any number of things to grind the bits. Once they have their basic shape, they will keep it for a long time since the machine is such light duty. If you know someone with a grinder, you could shape the tools with it and just keep a $4 stone for touching them up 'on site'.
Jeweler's saw, with good blades: It will cut without too much difficulty, on the thick end, 3/8" aluminum/brass with scroll saw blades for wood, or 1/4" steel with coarse jeweler's blades. It will cut as thin as you desire, especially with a backing board. The blades are impressively resilient; I use it with a #4 blade for cutting M5 and smaller screws when I've only got one or two to do. I'm pretty sure I have hairs thicker than the finest blades.
Mitutoyo Calipers no. 530-312: I like these a lot, though if I could get them again I'd buy no. 522-602 for the flat face. I'll probably like digital ones more when my eyes are old, but for now I like a couple things about the vernier scale. The inch/mm scales are always waiting there. It's just about error proof, and very hardy. I'll keep using them after I drop them, or spill half a container of loctite on them. I use them for transferring measurements all the time, with the four reference surfaces.
I've got dial calipers too for when I want to measure odd things quickly, but I'd take the vernier ones if I could only have one pair.
Fountain Pen, Noodler's ink: For marking fabric, writing, and drawing. The line width stays the same, the ink is permanent and waterproof for better or worse, and nothing has to be thrown away for a decade or more. Noodler's sells Heart of Darkness ink with a free pen for $19. That would last me five years, probably.
9mm Olfa Knife: It's good to have a very sharp knife for cutting paper. It's easier said than done, since for really small stuff, it's too dull after only a few meters of cutting. I keep a lot of other knives shaving sharp, but I don't want to wear the points of them down on dumb cardboard experiments. This has 13 points per sharpening, at $.03 per point. I strop the strip of blades all at once, so they're sharper and maybe a little more durable than new.
Knipex 23 01 140 Pliers: My favorite ones. I use them for sewing thick stuff, and often in place of tweezers.
