On May 20, 5:01*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Woof! *I've done 19"x19" PCBs in a home-made etching tray, but DAMN! *80
inches?

19 by 19 is 361 square inches. 6 x 80 ils is 480 so not all that
much bigger.

*I'm also thinking if I get any undercutting, it'll condemn the
'spring' after a few tens of thousands of flexes, and I need millions
from this (another reason for the length vs. travel).

I've seen .002" copper under-cut (badly), so I suspect .010 might, too.

Lloyd

I would presume you etch from both sides , so it is as if it were
only .005. But you are right. You might have to make the pieces a
bit wider, rolll the piece up and sand the edges. One experiment
would show you how much of a problem undercutting presents.


Dan