On 4/30/2014 12:07 AM, pyotr filipivich wrote:
I'm back in school, retraining to be a CAD guy. As I say, when I
first took drafting, it was pencil on paper, "Computer Aided" meant
we'd eventually have robots to put the ink on the paper to make
duplicates. So, now I'm at that part of the course where we start
focusing on the other end: drawings. Getting all the dimensions and
notes and "fiddly bits" on the "paper".
So yesterday, Brent asks if the drawing is good. "Well ... (grab
a mechanical pencil from my shirt ... which just happened to grab the
one with the red lead.) this is good, you forgot this dimmension, you
need a note for the knurling, and ... oh there is a 'trick' to define
chamfers in one click, I'll show you..." You _have_ to have
everything defined, no it is not 4x .19" x 45° ... I think he was
getting a bit flustered and wasn't "seeing" the completed part ...
We decided there was too much work to recover the drawing to get
that last point (he already had 24 of the 25).

But I was thinking "I just need to have those dimensions in order
to make this."

Same goes for the fit & tolerances exercise. I missed it the firs
time because ... well, interferences get added, while clearances get
subtracted. And being, on occasion, a bit of the show off - I found
that the appendix to the textbook was in error. Or at least did not
match up with the table in the Machinery Handbook. On consultation
with The Boss/ Instructor, we decided that we would go with "company
policy" (the text book) rather than 'buck the system.'

Oh well, now I'm trying to remember how to get a surface in
Mastercam for the next project.

Stressful as it can be, I'm having fun.


--
pyotr filipivich.
Discussing the decline in the US's tech edge, James Niccol once wrote
"It used to be that the USA was pretty good at producing stuff teenaged
boys could lose a finger or two playing with."



Study the great CAD books by M.C. Escher.