"jon_banquer" <
jonba...@yahoo.com> wrote in message
news:69859aef-b214-4775...@googlegroups.com...
CNC is little help without a CAD file, which you don't have when
making repair parts.
Segway's experimental parts were mostly made manually, cut-to-fit, on
a CNC Bridgeport and lathe. I rarely saw them running CNC files,
usually an engineer was working from a sketch and inventing the part
on the fly.
The files that castings had been made from didn't help without the
production machining fixtures to position them. I had to reconstruct
their hole patterns relative to locatable reference features, then
locate and center-punch new holes with a height gauge and dividers
while they weren't stressed by clamping. Thin-walled plastic injection
moldings were particularly difficult to clamp securely enough without
distorting them.
Expensive CAD seats were in heavy demand. The only one I could borrow
was for the powerful but quirky circuit board design program which
didn't talk to SolidWorks or the milling machine. It was quicker to
just manually mill a one-time part from the drawing while the machine
was free than to manually translate and enter the G code.
There was a considerable speed advantage in being able to make
non-production stuff in-house rather than cleaning up the drawing
enough to send it out.
-jsw