RE: Some reliable equations for RT

From: Ian Gibson (
Date: Wed Feb 06 2002 - 08:28:19 EET



A friend of mine once coined the term "artificial skill" as a contrast to
"artificial intelligence". We were working in the robotics field at time
and he was working on a number of projects, including one to play the game
pool. What he concluded was that we didn't really want machines to replace
human intelligence, but machines to replace human labour. The first
generation of robots were designed to replace the 3D tasks (Dirty,
Dangerous, Dull). What he wanted was to add a fourth D, that of Difficult.
This doesn't apply just to robots, but to all forms of automation
(including RP). As machines become more complex, so they are capable of
replacing more and more human tasks. Those that are being considered now
are the tasks labeled Difficult and we, as engineers, are charged with the
job of creating such machines.

I believe the quality and craftsmanship you are referring to is in this
area. In RP we now have technology that can be said to replace some of the
skills required to generate, or realise, works of art. Similarly computers
can be analogized to painting, like RP is to sculpture. If we have this
technology, should we also maintain the traditional skills?

This is one thing that fascinates me about Japan. Here is a country that is
famous for technology and level of automation, both in industry and in
daily life. However, it is also famous for keeping many traditional manual
skills alive. It seems that automation certainly enhances our lives, but
the ability to create things with our hands and the simplest of tools
enhances our well-being.

I sense that you are lamenting the fact that we no longer have to work
(i.e. physical labour) to create the results of our imagination. I
sympathise, but also note that many artists have also embraced, and
enhanced, this technology.

I'd like to go on, but will stop there for now. I wonder what other people

A final question. I seem to have addressed your point about craftsmanship,
but am confused about your use of the word "quality". In what way do you
perceive that quality is being compromised? Or is it that you are just
referring to the quality of manual output?


At 09:12 PM 2/5/2002 -0500, you wrote:
>I am new to this list and I wanted to introduce myself. My name is Molly
>Epstein, I am art student and am very interested in rapid prototyping
>processes. I don't know if this list gets philosophical or if it just
>technical, but it seems pretty informal and welcoming. This post from Lamar
>Davidge made me think of a lot of things that I believe to be a really big
>problem in my experience with people. My school is the only college that I
>know and it is what I am responding to, so bare with me but I really feel
>the next generation of students coming out of great art schools really do not
>know the fundamental requirements of making things work well, and using tools
>and machines correctly, not just making mistakes but really not understanding
>the way things work. It seems that we are rushed and pushed away from
>learning how things work, or how to do something with the best craftsmanship
>and quality. How do any of you feel about this? Have any of you seen a
>digression in quality and craftsmanship throughout your time doing what you
>are doing?
> >
> > You forgot to mention that tool life is also affected by the ability of
> >the employees who are responsible for running the tool. I have seen some
> >very simple tools ruined on the first shot due to mistakes, a 150 ton press
> >closing on an aluminum or epoxy tool can wreak havoc, not to mention what
> >injecting at 2500psi, instead of 350 psi, can do to a fragile tool. Also
> >epoxy is very strong, but if you drop it on the floor with the core side
> >down it wont last long. The best constructed tool, with the best possible
> >design, wont last long if you dont have people who are skilled running it.
> >
> >Lamar Davidge
> >-------Original Message-------
> >
> >From: Pattison, Will
> >Date: Friday, February 01, 2002 06:35:11 PM
> >To:
> >Subject: RE: Some reliable equations for RT
> >
> >in my experience, the only equation that can be used to determine shot life
> >in a rapid tool is something like:
> >
> >tool life is inversely proportional to part complexity, inversely
> >proportional to how many parts you need, inversely proportional to how much
> >your customer is willing to spend, inversely proportional to how fast they
> >need parts, directly correlated to the material they want, and directly
> >proportional to the real toolmaking knowledge that goes into design of the
> >rapid tool.
> >
> >i'd be curious to see any mathematical model that effectively takes all that
> >into account.
> >
> >will pattison, skeptic
> >product development
> >ignition
> >plano, texas
> >
> >
> >-----Original Message-----
> >From: Chang-Shik Min []
> >Sent: Friday, February 01, 2002 9:23 AM
> >To:
> >Subject: Some reliable equations for RT
> >
> >
> >
> >Dear Rapid Tooling specialists:
> >
> > are you today ? I have survived this field of RT research since
> >1994.
> >Based on statistics,probability and stochastics,I have been trying my best
> >to simplify all the RT business processes,especially for quoting and process
> >
> >control.
> >Meanwhile,I have recently come up with some highly reliable empirical
> >equations for tool (which is made by RT methods)life estimation,part cost
> >estimation for low-mid volume production from RT molds.
> >Is there any one who has ever tried to make some empirical equations for RT
> >?
> >Any comment you could give me would be greatly appreciated.
> >TIA
> >
> >
> >
> >
> >
> >
> >_________________________________________________________________
> >Join the world's largest e-mail service with MSN Hotmail.
> >
> >
> >
> >For more information about the rp-ml, see
> >
> >For more information about the rp-ml, see
> >
> >
> >For more information about the rp-ml, see
> >
> >
> >For more information about the rp-ml, see
> >
> >
> >For more information about the rp-ml, see
> >.
>For more information about the rp-ml, see

Dr. Ian Gibson
Department of Mechanical Engineering
The University of Hong Kong
+852 2859 7901 (O)
+852 2858 5415 (F)
+852 2817 1784 (H)
+852 9873 8281 (M)

Light travels faster than sound. That is why some people appear bright
until you hear them speak.

For more information about the rp-ml, see

This archive was generated by hypermail 2.1.4 : Tue Jan 21 2003 - 20:13:26 EET