I measure 3 times and still need to print at least 3 times to get something right.

I'm working on an outdoor hose grommet that's a custom fit to my house. I measured with calipers. I also took paper, traced the fixture and marked the holes before modeling and 3d printing.

I have a desk full of badly fitting prototypes. -or just bad because I forgot to set a print setting in the slicer.