I think it's been a long time since farmers cultivated their own seed though, even before roundup-resistant and GM crops were commonplace. It's a very different science and skill to growing crops.
For these crops, it's not a very different skill. You just have to clean the seed and ideally test germination rates, though many farmers do not even do that.
Side note. There also air bearings which are also pretty awesome but require tight machining tolerances. They are used in the semiconductor industry for some things. Mainly because you dont want lubricant to dirty the enviroment, but the tighter tolerances also help ensure a spindle/shaft dont wobble as much.
Edit some time later: And then perhaps I'll go down an hours-long rabbit hole watching all his videos and learning a ton about machining...
Are there people without accents that explain things? Because that would be a video I want to see.
Of course, these days, a lot of the accents are disappearing because of mass communications, so the "American accent" is homogenizing, but those other accents aren't completely gone yet.
For example, if you have two speakers with English as a first language and a third from Germany with English as a second language, the native English speakers will probably detect a German accent in the ESL-speaker's dialect.
People get into long internet arguments over this, but the closest thing to a neutral English dialect is General American English, also sometimes called Broadcast English because newscasters, TV personalities, and actors would be trained this dialect so as to not sound like they are "from" anywhere in particular. It used to be common as well for highly-educated or upper-class individuals to hire speech coaches to teach them this dialect in order to "lose their accent". It still may be common for all I know, but I believe the deliberate acquisition of General American is probably on the decline.
>If you don't replace the oil regularly, or let it get so hot it flows out of the journal, the bearing will wear and need replacing.
It's still going to wear out from cold starts and the entire rest of the engine that doesn't have pressurized lubrication is also going to wear out eventually so there's no point in trying to outlast all those components since you're gonna have to take it apart to deal with them when they reach EOL and you can just deal with bearings at the same time.
As much as I love lugging around rotary tables and indexing heads a machine shop that makes triple digit part quantities would be stupid to run old machines (too many man hours per part) and a repair machine shop would be stupid to finance a new 5-axis.
Equipment in most industries moves from low margin, high duty cycle operators to operators with either higher margins and/or lower duty cycles.