RE: [rp-ml] milling=am?

From: Marshall Burns <>
Date: Tue Jan 12 2010 - 19:21:17 EET



Your question has been a heated subject of debate since the beginning of the
RP-ML. I will give you my take.


The general term that includes both additive and subtractive fabrication is
"digital fabrication." The general term for making products using these
technologies is "digital manufacturing." This is because the key
technological element of both additive processes and CNC milling is that
they work from a digital description of the desired product.


Digital fabrication, either additive or subtractive, can be used for
prototyping or it can be used for making replication molds, mathematical
models, medical models, digital sculpture, and in some cases for
manufacturing of final products.


Prototypes can often be made by digital processes, but they can also be made
very quickly (although not as accurately) by hand. Thus to name additive
fabrication "rapid prototyping" is a misnomer.


To quote from my talk, "The Freedom to Create" in 1994


     Some proponents call this technology "rapid prototyping" because
industrial prototyping was the first major application of the new additive
fabricators, like the StereoLithography Apparatus (SLA) from 3D Systems.
Hundreds of millions of dollars in productivity gains have been realized by
the few hundred companies around the world who have been using these and
similar machines to make prototypes of new machine designs. But to call
these machines "prototypers" misses the whole point of what is happening
here. Calling an SLA a "prototyper" is like calling an automobile a "grocery
cart" because one of its first important uses was in rounding up supplies
for the family, or like calling a book a "scripture" because one of the most
popular books ever published has been the Holy Bible.


     SLAs and similar machines are not prototypers, although they may be
used that way. These machines are fabricators, because they create new solid
objects out of amorphous material and computer data.




Marshall Burns <>






From: [] On Behalf
Of The Creature Company
Sent: Tuesday, January 12, 2010 06:02
Subject: [rp-ml] milling=am?


I believe we had the discussion before but I have searched the archives and
haven't seems to locate the thread.


In the move to rename the technology we use from RP to AM how do we classify
CNC and Milling? CNC and milling are to be subtractive in nature. They
obviously do not fit into the realm of additive manufacturing however they
are a rapid technology.


That makes we wonder if the terms RP and AM are not synonymous but set up as
a hierarchy, whereas rapid prototyping includes additive and subtractive
manufacturing. Am I correct in saying that?


I have been a bit flustered since I felt the push was not to use the term RP
any more since it's "not cool". Thoughts?


Received on Tue Jan 12 19:27:44 2010

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