"pyotr filipivich" wrote in message
...
"Jim Wilkins" on Sat, 21 Dec 2019 07:45:20
-0500 typed in rec.crafts.metalworking the following:


I retrained as a CAD guy. I remember a two part assignment:
design the casting, then design resulting part. I thought "If I
make
the casting suchly, then holding it for the machining will be
easier."
And transferring "the sketch" to the drawing I said "I can make
that" meaning all the info I need is there. Except for the note
about
the material, forgot that. Oops.


Yes, let them choose the alloy that gives them the best results and
then send a revised print.

When I talked to circuit board makers before sending out a quote
package they often would tell me they'd make the board differently
depending on their equipment and supplies on hand, so I had to adjust
the quote to fit all of them by removing some specs and relying on
past experience with their quality. For these RF circuits the signal
trace impedances were determined by my line widths and their inner
plane spacings and insulation dielectric constants.

Throughout the 70's and 80's I watched them improve from loose
commercial to demanding mil-spec standards and process control for all
their products. Everything else benefited from their ability to make
circuit boards for defense contractors whose tech was 20 years ahead
of civilian applications.