Blanking dies (RT)

I just finished putting up an article on how to make these dies
with the added cability of punching out a center opening at the
same time. Called by various names, they are commonly known as
“blanking dies”, “RT dies”, or as “Pancake Dies” at Douglas
Aircraft where the process was developed. During the '30s when
they were building the DC-3, the size of some of the parts
exceeded the capacity of their presses. They needed a low-cost
way to blank out large parts, and worked with Do-all Saw to come
up with a punch and die that did not require a die shoe, or
guide posts.
What came out of the collaboration was a punch & die concept for
sheet metal that was sawn from a single piece of metal that kept
the punch attached to the die by never completely cutting it
loose! The neat thing about it is that it can be sawn out with a
jewelers saw or scroll saw and is capable of cutting material as
thin as paper, or as thick as itself.
Your immediate reaction is that “You can’t do that! The saw
blade leaves a kerf and you won’t cut butter because the punch
and die has way too much clearance”.
My response is:"Yeah, but if you saw the metal with the blade
off of vertical, you can wind up with a die set that has perfect
zero clearance, and can be made in an hour or two of sawing. For
short-run production work they are ideal. Costing only 2-3
dollars, you can be blanking out parts in a couple of hours (for
the first one). My article is in the “Learn” section of my
website where I keep putting new on ways to use the
equipment that I make. It is not my purpose to make you wade
through massive amounts of website stuff to get to it. The URL
takes you directly there. Please check out the “Artists Gallery”
section also.
The ability to blank out the outer contour of a part using this
process has been available to the jeweler/metalsmith for several
years. It is possible to form a part first and then use the die
to trim off the excess metal. The basic method was written about
in the book: Hydraulic Die Forming for the Jeweler/Metalsmith by
Susan Kingsley ISBN 0-9635832-0-4.
I method that I describe adds the ability to pierce cut an
opening in the middle of the outer part at the same time. This
could be for a heart shaped opening, for example. I think that
the process is an indispensible one for the jeweler. Check it out
and I think that you will find the trip rewarding.

http://www.bonnydoonengineering.com/learn/interior.html

Lee
bonnydoonengineering.com

hi lee, nice to hear form you! i have to confess that i’ve been
going to site quite often looking for this article with great
anticipation. thanks for getting to it!

best regards,

geo fox

aka dipsh*t

hi lee, nice to hear form you! i have to confess that i've been
going to site quite often looking for this article with great
anticipation. thanks for getting to it!

Hi…sorry for the delay in getting it up. “I made a list and
checked it”… dozens of times, and there is still an error in
it! The countersink should be a #3, not a #2. Not a big deal, and
nothing lost, but still an annoyance.

Lee
bonnydoonengineering.com

Hi...sorry for the delay in getting it up. "I made a list and
checked it"..... dozens of times

Well, Lee, I’m glad you’re being so energetic by doing a site
and keeping in touch in other ways at all. I appreciate having
you on-line, and I wish more companies showed such nous and got
digital literacy.

Brian
B r i a n �� A d a m

j e w e l l e r

a n d �� e y e w e a r �� m a k e r

s i n c e ��1 9 8 1

http://crash.ihug.co.nz/~adam/