So I want to create my own electronic parts from scratch,I don't like buying stuff from internet because it's mostly expensive and I believe if you make it yourself its more cheaper. You might ask what I mean by electronic parts. The simple ones like Ultrasonic sensor,Servo motor and other type of sensors. Yeah I know there is factories out there making that stuff and making one by hand is hard and sometimes impossible due to small size.So my question: where do I find book,pdf or something that tells me how to make them?
If there is no answer to what I ask above then I highly need schematics for that kind of things(ultrasonic sensor for example).Very detailed and serious,not basic things that show only visible areas. I believe its written in academic books and are taught in universities but right now I don't study in good university so I don't have that kind of books.I mean if there is factories out there building that small electronic parts there have to be any FULL manual,schematics or design for that things. Where I can get that schematics or specific books that show how they work,designed,which materials,sizes of specific areas etc?
In the end my question is very easy,that factories have some information on how to make some exact parts(like ultrasonic sensor),where do I get that information too?