BTW, the wisecrack about you being young. It wasn’t meant as an insult... more along the lines of you have more time than most here.
As you get older, saving time becomes more important if you’re trying to get stuff accomplished, ya know.
And the more time you save on work, the more you have to waste on fun stuff
I’ve actually used the "file method" more-or-less. Prototyping a race car part ... it required a channel running down a bored hole in a block of aluminum. I drilled a hole where the channel would be, bored the hole, and then squared it up with files and a jig. It took forever and was a real PITA, and that was 4" long and in T6, but it got done with the tools I had at hand... wouldn’t even think about doing it in steel. That’s what real machinists and money are for.
I’m just a hobbyist.