On Jan 3, 9:58*am, "Jim Wilkins" wrote:
"Jonathan Banquer" wrote
On Jan 3, 4:27 am, "Jim Wilkins" wrote:



The flip side is machinists with no clue about Statics or Dynamics
who
take shortcuts like this one ...

-There is no flip side. You either pay your dues making lots of
-different parts from lots of different materials and become a real
-machinist or you don't. You don't need a CNC machine to make lots of
-different parts from lots of different materials.

I designed and built equipment where the electrical properties of
machined surfaces mattered a lot, for skin effect or corona discharge.
I didn't have stress risers on my lightly loaded parts but they are
another cause of disputes. When the machinist didn't understand why an
outside corner needed a large radius and smooth finish, but not close
dimensional accuracy, they took the easy shortcut and then gave me lip
until management had to order them to do it RIGHT.

In general they assumed they knew more than the damned college boys
and if they didn't understand the science driving a difficult
requirement they resisted meeting it. The college boys stopped
fighting them and made me the shop liaison, partly because if they
made too much trouble I could do the job at home or bid it out to
experimental shops I'd worked with in the past.

"When the machinist didn't understand why an outside corner needed a
large radius and smooth finish, but not close dimensional accuracy,
they took the easy shortcut and then gave me lip until management had
to order them to do it RIGHT. "

The forgot to mention the other side of the story which is far more
common:

Arrogant, ignorant engineers who don't understand machining and who
don't think they need to learn anything from a machinist calling for
needless small radius's in the bottom of deep pockets. They whine like
spoiled little bitches when their part is so expensive / takes to long
to machine.