I'm pretty excited about this little development of mine: I've been teaching myself to use FreeCAD software, and what better simple exercises than to generate some camera repair tools I really wished I had? Like a miniature spanner to remove the screws of on a Kodak Retina IIa, or the slotted nut which anchors the flash synch socket of a Praktisix!
3D printer: Even the smallest, least expensive will likely do fine: I used a secondhand Monoprice Mini Delta and ordinary PLA media. I couldn't actually print clean 1 mm holes as shown in the CAD rendering, so I drilled those out by hand using a 1 mm drill bit mounted in a pin vise. Actual pins are 1 mm piano wire, shaped by hand or Dremel tool as needed. I designed mine to fit my ratcheting screwdriver. Because these tools are so small, the print time is only a few minutes.
Initial test using my tool to remove Retina IIa screws: Whoa, they spun loose with no drama at all.
I'm finding that as I gain basic CAD skills, it's easy for me to modify my basic designs, so I can have all of the oddly-sized miniature spanners that I need. I expect that building my own Nikon A/R ring removal tool will be no more complicated, save that I'll need to grind the steel pins a little bit differently. And when I get a more pliable printing material, perhaps I could create my own flexiclamp wrenches on demand too: So many possibilities here.