Forgive me if don't do a good job painting this picture in words:

Picture a piece of 18- or 16-gauge aluminum, bent in a square "U" shape.
The arms of the "U" have holes in them that need to be at fairly equal
height up from the base of the "U" (20 mil is good, 50 mil is acceptable,
100 mil is definitely not). Dimensions are about 8 inches deep (i.e., we
start from a sheet 8" wide) by six inches tall by four or five inches
wide.

Assuming that we can reference the holes with perfect accuracy to the
edge of the sheet that will be at the top of the "U", how closely can we
get the hole heights, if we bend the part in a pan brake?

I'm thinking that if the break has a stop that registers that "top" edge
of the U the same for both sides, that we should be able to do better
than 20 mil most of the time, and never exceed 50 mils unless there's
just something wrong with the equipment.

Does this sound reasonable to you, or am I all wet? Is this something
that a normal sheet metal shop should be able to do, if they were
provided with suitably cut sheets?

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com