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RT Blanking System


#1

(1) a friend of mine has offered to give me a screw press. Is it
possible for me to make good use of it without having to spend $330
for the RT Blanking System? I have looked in a number of my
jewelrymaking books for advice on how to use a screw press, but none
of them describe it.

(2) There was an Orchid thread discussing the making of dies after the
fashion of the RT Blanking System, but I cannot seem to access the
Orchid Archives. Can anyone advise me on what I am doing wrong? I
go to the Orchid/Archive web page, scroll down to the "Meta-Index,"
and try

to open the heading “Subject Info” for a certain month/year. Our
Macintosh then downloads but the only result is a blank
page.

Thanks in advance! Judy Bjorkman Lenandjudy@acmgfcu.net


#2

When Rio Grande was selling the RT Blanking system, it was shown with
the screw press. I have their instructional video and it shows the
screw press in use with pancake dies. One of my Canadian jewelry
instructors made her own angled bench pin to cut pancake dies well
before the RT system was available in the U.S. Her bench pin was not
adjustable like the RT, so she used only one thickness of steel for
the die and 18 gauge metal. Donna in VA


#3
  "... One of my Canadian jewelry instructors made her own angled
bench pin to cut pancake dies well before the RT system was
available in the U.S...." 

OK, Donna, for those of us having a hard time visualizing this, how
about a little more detail?


#4

RT is not very available if at all. For better
on what is actually he same thing see:
http://www.bonnydoonengineering.com/index.html Get Susan Kinsley’s
book on Hydraulic pressing from them. get on the BD forum and ask
your questions.

The RT. die patent is pretty invalid – the technique was actually
use by douglas aircraft doing WW2 building airplanes. and has been in
use cutting other type dies more than 50 years.

For RT. type dies check with Dar at: http://www.sheltech.net/ He make
good dies reasonably. No learning curve , sawing and heat treating
etc.

These dies are best described including the reason for the angle
and suggested angles for specific saw widths and die thickness in
The Kinsley book.

Described in words As clear as mud: AS far as the angle cut is
concerned , sketch a typical metal thickness and then sketch in a
straight slot cut at 90 degrees with a specific blade. AS you rotate
the saw blade cut off 90 degrees you will notice that the clearance
can be reduced so that the two sides will just touch when moved up
and down. In actual practice you will want the two pieces to not
quite touch. The angle can for a specific die and blade thickness
can be easily determined by trigonometry if you are so inclined. The
actual clearance is an empirical thing. Get the book.

Jesse


#5

Hello all,

Hydraulic Die Forming for Jewelers and Metalsmiths by Susan Kingsley
has an excellent chapter on blanking dies. She gives very detailed
instructions and includes a table in the back of the book that
determines angle of cut based on thickness of tool steel and
sawblade.

Sawing blanking dies is really very easy. It just takes a bit of
practice. I have a drill press with a tilting table that I c-clamp a
bench pin to. A magnetic protractor ($10 at my local hardware store)
tells me the correct angle to tilt the table. I have a small painted
drill bit inserted in the chuck that I use to check my saw blade to
insure it stays at 90 degrees. I have learned to lock my elbow and
use my shoulder when I saw to keep the saw blade steady.

I blank out pieces of silver and gold 26 and 28 gauge. I have never
had to heat treat a die, perhaps because I use such thin metal. I
have some dies I have used for 8 years and blanked out thousands of
pieces from. I didn’t have a hydraulic press when I started. I
placed my die, with metal inserted, between two sheets of 1/4 inch
tool steel and pressed the “sandwich” in the jaws of my bench vise.

I hope this info will motivate any of you who have wanted to try
this technique but thought it might be too complicated. It opens up
so many possibilities for working in multiples!

Best regards, Jayne Redman


#6

On the subject of die saws , Jim B. explains how the precision of a
sawguide and toolsteel isn’t actually necessary for “quckie” dies
for short runs of parts in soft metal.

Quite right Jim, and the Rio RT saw is still next to useless in my
(not very often) humble opnion. The BD unit is way better. I’ve gone
through a couple of homemade ones and now I use two customized BD
units . Never liked scroll saws for this, maybe I didn’t get the
right one, or give it a fair shot. Whatever… I don’t like them
and I’m certain that I get better blade life on my saws.

Using mild steel is a good way to make the job easier, as is using
larger sawblades . I use #1’s most often, and 2’s and sometimes even
4’s on big, thick dies. The 2/0 and smaller I save for detailed
shapes and sharp corners. Since I sell dies to people I always use
the 0-1 tool steel and heat treat it , but certain applications are
very hard on even the toughest ones I can make.

The latest minor miracles I’ve gotten to work are for a customer who
makes copper garden art. One is a pig’s face and the other a dog’s,
each about 6" by 4.5" ,and they both cut the shape and form it
dimensionally in one press operation , to a depth of about 1/2 " .
The dog is actually 8.3 " wide from ear to ear and I had it cut on a
wire edm.Both have a separate base that they sit on that has a mold
area that has a conforming female die cast in plastic steel,
matching the cast aluminum male die that’s attached to the blanking
die.

It’s just really a solid conforming die set integrated with a
pancake die , but the most recent development helps form the metal
with more depth and less wrinkling. It involves placing a thin
urethane pad as a buffer between the die parts, so that the metal
interfaces directly with urethane, but just a thin layer, and is
mostly forced to conform to the solid mold parts. The urethane also
cushions the plastic steel from the direct, and in these
situations very abrasive, contact with the metal.

This has really pushed the limit of what I can do in one step, which
translates to lower cost for parts , which is an essential …
sort of prime directive for this particular customer. They don’t pay
very much per piece but they give me a lot of work, so we’re both
happy. Needless to say, this necessity has been a great stimulus for
innovative production-style solutions using pancake dies and press
forming.

Dar Shelton