On Dec 8, 2:08 pm, "Paul K. Dickman" wrote:

There was an article about using steel filled epoxy for short run draw dies.
They were making the same sort of panels. They were aluminum aircraft
panels, if I recall correctly, but I imagine the state of the art has
advanced in the last 45 years.

Paul K. Dickman

Epoxy dies are used for springback analysis before the hard dies are
even cast. Draw dies (first operation, just after the blank is cut
from the roll) look only roughly like the panels that come out. Lots
and lots of springback. They're trying to deal with that using FEA
now, but it's not perfect. Soft tooling is still required for really
screwball panel design.

Things are like door and hood outer panels aren't too bad. Designers
are trying to reduce the number of panels required by basically
stamping out larger panels which are more complicated. Many inner
panels have very complicated geometry, the springback of which cannot
be accurately predicted by FEA analysis. I worked on the current BMW
X5 floor pan panel. I think the previous generation vehicle used 4+
stampings, which is now just one panel. Lots of time spent on that
soft draw die.

Regards,

Robin