Do it yourself has something ... I needed a 10 ° angle cutter, but had none (if there is even one to buy). In the old craft tradition, the craftsman makes his own tools. The material question was quite simple: Silver steel (115 CR V3) can be processed with normal tools and easily hardened.
The design has to be in a way that I could make all three faces of the cutting geometry with a normal cutter, for this I first started drawing with my CAD (MEDUSA4) :
To get a positive cutting angle, the first notch is milled below center. The 10 degree in the tool path is easy for the X/Y table of a CNC controlled mill - same is true for the 30 degree rotation for the free face with the also for CNC operation modified rotation table. The next 6 faces are simply repeat. That the tool gets four edges is simply a result of the geomety. The reference points for the gcode i've simply measured out of the CAD, i write all my programs line for line myself, they have only a few lines each. After the milling it heated it up to glowing red, quenched it, cleaned it so you can see the heating colours and heated it up to a dark blue and quenched it again. Some work with a sharpening stone and the front teeth i've grinded free-handed. It was just made for wood cutting anyway.
Because I'm just into it: that is also a nice illustration of the jack-of-all-trades-principle: I had to work on some front edges later on another occasion:
I needed this 16 mm roughing cutter for a series of aluminium turned parts to get a starting hole big enough for the inside cutter. Now i have (i never officially learned that profession) learned on the hard way that in aluminium only really sharp tools are fun, even if the AlCuMgPb which is made for automated processing. After 70 holes that wasn't really true anymore. Normally, you'd give it to a sharpening service, but on the one hand it takes a few weeks, you have to collect some tools (otherwise it is with the postage more expensive than a new one) - but i needed it now. So i looked into it and saw that i could reach the egdes on a sharpening stone. I started carefully, i just needed a tiny bit off - and it worked. Normalerweise hätte man das Teil zum Schärfdienst gegeben, aber zum einen Mal dauert das ein paar Wochen, man muss sammeln (sonst ist das Nachschärfen mit Porto teurer als so ein Fräser) - ich brauchte das Teil aber jetzt. Also habe ich erst einmal festgestellt, dass ich auf dem Abziehstein an die Schneiden dran komme und dann vorsichtig losgelegt, es brauchte ja nur einen Hauch. For drills, it is even more easy, i grind them myself completely:
That is not even complicated, because you see on the angle of the cutting edges if you got it right. The important cut on main- and cross edge is straight, only for the free edge you need to rotate and lift the drill to make space.
I don't know if that is typical for INTJs, but the story around this article is a showpiece for my line of doing something: basically, i just wanted to copy the articles from Facebook to here. But they were a little bit short and i thought i can write something more. Then I needed the sreenshot of the CAD for a better understanding and the pictures of the tools ... and on the way (look at the difference between the third and fourth picture) i found out how to make these macro pictures with a really white background:
Additionally to the ring flash (i used that one for the other pictures, too) i added a second flash, which only lights the sheet of paper and makes it white. The other information, because i'm into it: EF-S 60 mm f2.8 macro, Orbis ringflash on full power, second flash on 1/4, manual mode, 1/250s f16 and 30 cm distance on the lens. With a smaller distance, the depth of field is too small, even with that small aperture.
That said, it is a nice example for Introverted Intuition: To make something out of nothing. The way to do that is a little bit of puzzling, but the ideas pop into my mind sooner or later. Sadly, I'm distracted easily (perhaps i'm INTP in that way), but you learn something all the way and on all the side paths which you can use somewhere else.