I get my money from my job which has nothing to do with machining, so all of the work in my shop is hobby stuff. I have the most fun when I am challenged; the more challenging, the more fun. The best day is when I fail because I make sure to learn something from it.
Generally, after I make something it goes out on the “metal” shelves which is a euphemism for the scrap area.
In machining school, they recommended to shoot for a thou tolerance and expect to fall short. They also said that if a tolerance is not written on the drawing, then assume .005”.
Understanding that I am just having fun in the shop, my target tolerance was chosen as .001” for now because I don’t think there will ever be any temperature control out there. My best case scenario of .0003” is probably optimistic, considering the lack of a controlled climate.
So my goal of .0003”-.001” tolerance is chosen, and not required by any means. To be honest, I would be very pleased if I hit a thou.