Blanking dies (RT)
Lee Marshall
I just finished putting up an article on how to make these dies. 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 information 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 inside a larger heart, for example. I think that the
process
is an indispensible one for thejeweler. Check it out and I think
that you will find the trip rewarding.
Peter W. Rowe
On , in rec.crafts.jewelry Lee Marshall <lmar...@scruznet.com> wrote:
>>I just finished putting up an article on how to make these dies. 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.
Probably, it would also be appropriate to mention where the commonly found
label, "RT" comes from.
The second page of a report on the subject of this type of blanking die for
jewelry use, from the Worshipful Company of Goldsmiths Reasearch Foundation,
dated May, 1980, by Roger Tayler (RT) is a publisher's note from the well
respected Director of Research of that organization, Peter Gainsbury. In it
he says:
"This report is a detailed description of a very low cost method of making
blanking tools for sheet metal and other materials using the normal skills and
tools of the jewellry or silversmithing craftsman.
The process was invented by Roger Taylor and is subject to British patent
application No. 21165/78. In the interests of the making of the information
available to all craftsmen, the Goldsmiths' Research Foundation has come to an
arrangement with Roger Taylor for the production and distribution of this
report"
While I don't doubt that Lee's info on the origins of this type of die are
correct, and quite apparently predate, by quite a margin, Mr. Taylors late '70s
research, it is also perhaps appropriate to point out that it's quite possible
that without Mr. Taylors research, and the resulting report which was widely
distributed, none of us would ever have heard of an RT type die, much less be
using them in one of Lee's fine presses, or any other equipment. ...
And just out of curiosity, does anyone happen to know whether that patent
application was eventually granted?
Peter Rowe
Robert Aurelius
The casting unit has been sold.
The following are still available;
dust collector with motor (jewelry buffer)
New Hermes engraving machine with power head,cutters,three sets of
letters.
Bob Aurelius
rau...@cloudnet.com
Lee Marshall
Peter W. Rowe wrote:
>
> On , in rec.crafts.jewelry Lee Marshall <lmar...@scruznet.com> wrote:
>
> >>I just finished putting up an article on how to make these dies. 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.
>
> Probably, it would also be appropriate to mention where the commonly found
> label, "RT" comes from.
>
> While I don't doubt that Lee's info on the origins of this type of die are
> correct, and quite apparently predate, by quite a margin, Mr. Taylors late '70s
> research, it is also perhaps appropriate to point out that it's quite possible
> that without Mr. Taylors research, and the resulting report which was widely
> distributed, none of us would ever have heard of an RT type die, much less be
> using them in one of Lee's fine presses, or any other equipment. ...
>
> And just out of curiosity, does anyone happen to know whether that patent
> application was eventually granted?
I don't know about the "RT" patent, although I have heard that it was
granted a patent in the U.K. I have the feeling that they still view us
as upstart colonials. In an article written in 1929, R.J. Wilkie, Vice
President of Continental Machine Specialties, describes (and shows a
drawing) of the saw blade going through the tool steel at an angle, and
using the sawn out piece as the punch,which is the essence of the
blanking process. It is fully described in a book entitled "The
Continental Process" that is 1" thick x8-1/2 x 11. Continental Machine
became Do-All Saw. One of the patent numbers is:
1,952,152 issued in 1934.
I will grant that Taylor was instrumental in bringing the knowledge back
into general usage.
The purpose of my writing the article that I mention in my posting is to
make available the ability to punch out an opening in the middle of a
part (and the inner part has no tabs). This is new to the
metalsmith/jeweler.