[Jewelry making - Article 00970] - Re: [Orchid] Stereo Lithography

[Jesse]

========[ Invite a Friend - http://www.ganoksin.com/invite.htm  ]========


>      Hello Every one Any one out there knows any thing on the subject
>     of stereo lithography? 

    Dear Anil, I'm sending along an exerpt from a comprehensive report
    given at a conference that took place in Japan a few years ago. The
    technology has progressively grown, but this information may help to
    give you an overview of the process from the perspective of someone
    who has implemented Stereo Lithography. 

    Mr. Matsumura has kindly given me permission to forward this
    information to the members of Orchid. 

    There are references to images that can be found in the full report
    on the linking web site.
    http://www.kingin.co.jp/english/conference.htm 

Hope this helps,
Jesse Kaufman


    APPLICATION OF RAPID PROTOTYPING TECHNOLOGY TO JEWELRY INDUSTRY AND
    REPORT OF A DESIGN CONTEST 

    INTRODUCTION 

    Approximately 30 years ago, the jewelry industry underwent a
    revolutionary change in production from producing unique items only
    to mass production as a result of the introduction of a new casting
    technology based on the lostwax technique. 

    In 1994 Meiko Inc., utilizing the know-how of Stereo Lithography
    developed by Industrial Research Center of Yamanashi Prefecture,
    manufactured a machine for jewelry production on a commercial basis,
    which marked the very first application of Rapid Prototyping in the
    jewelry industry. 

    This new system was expected to effect another revolutionary change
    in production after the introduction of the casting technology in
    terms of labor-cost saving, shortening of time for product
    development, new design development, etc., but it failed to become
    popular because: 

    1.The gaps on the surface of the model did not meet the requirement
    of the jewelry industry that demands complex configurations. 

    2.Compared with western countries and those in the South East Asia,
    Japan was much behind in terms of computer education partly because of
    its unfamiliarity with the keyboard, thus, the number of CAD operators
    who input data was unarguably insufficient. 

    3.It was difficult to cast the ultraviolet-cured resin directly as a
    dissolving prototype. There existed such major problems, but
    furthermoRe: 

    4.The price of the machine and the replacement cost of the laser
    were so expensive that it was difficult to justify the introduction
    of the machine financially. 

    5.The timing was bad as the jewelry industry then was suffering from
    slow business. These problems existed among many as well. 

    Under these circumstances, however, some companies brought in the
    system and challenged the difficulties. company in Kohfu aggressively
    utilized the Stereo Lithography apparatus made by Meiko, Inc., but
    swallowed by the rough waves of sluggish economy the jewelry industry
    was faced with then, it went bankrupt. W company, which took over the
    machine, also met the same destiny. H company, which introduced the
    system at an early stage, also went bankrupt and there spread the jinx
    that any company that would bring in the Stereo Lithography apparatus
    would go bankrupt. 

    Against all odds, however, a few companies successfully introduced
    the system and they are now still using it. Unfortunately, these
    companies are all small businesses, and as they do not have any
    engineers with a theoretical mind, the aspects of improvement never
    went beyond the realm of the workstation. 

    MATSUMURA'S STRATEGY (CAD) 

    Under these circumstances, in November of 1995, Matsumura Gold and
    Silver Co. Ltd. started to use a CAD system and challenged the second
    aforementioned problem about the CAD data input by training many of
    our engineers, which resulted in the system whereby we could input
    data even for some complex designs quickly and economically. 

    A little later, in July of 1996, we introduced a Stereo Lithography
    apparatus called Unirapid made by Ushio Co. into our line, and
    started to market our service of producing prototypes for jewelry as
    a service bureau.We have made presentations on all of what we have
    achieved thus far at Japan Jewelry Fair (JJF), one of the major
    jewelry fairs in Japan, in two consecutive years of 1996 and 1997. 

    Currently, we are using Rhino Jewelry Version as our CAD system,
    which is a specially customized version of Rhinoceros, and we are
    selling it too. Also, in February of 2000, we also brought in an
    inkjet modeling system called ModelMaker II, manufactured by Sanders
    Prototype, Inc., which is now being used side-by-side with the Stereo
    Lithography apparatus. 

    MANUFACTURING PROCESS OF JEWELRY 

    Traditionally, the process of manufacturing jewelry from drawings to
    products has been as in Figure 2 As a result of the introduction of
    Stereo Lithography, it was changed as in Figure 3. 

    Unexpectedly, as you can find in the figures, more processes are
    added in the latter system. The reasons for this are as follows: 1.Sin=
ce
    casting from the UV-cured resin costs the quality of the final
    product, the model has to be replaced with one of the wax from which
    casting is done. 2.Since the resinous model cannot be refined as
    beautifully as the metallic one even if worked on directly by the
    craftsman, the metallic model needs to be made. 

    By using UV-cured resin for the model directly for casting purposes,
    we could eliminate the processes 4 to 5 in Figure 3; there existed,
    however, a couple of obstacles. First, the resinous model excels the
    casting shell material in strength as well as the co-efficient of
    thermal expansion; therefore, when heated, it destroyed the casting
    shell material due to their difference in the co-efficient of thermal
    expansion. Second, when heated, while wax is dissolved away, thus,
    hardly remaining, the resin does not liquefy even at high
    temperatures making it extremely difficult to remove it entirely. 

    We have solved these problems through various means including
    developing a new casting shell material.Notwithstanding, we have now
    come back to the process in Figure 2, where a silicon mold is built,
    for the following reasons; the quality of the final product made from
    the process where the resin is used as a direct model for production
    is not as good as the one made out of the wax-used process; casting
    from it is difficult and the rate of failure is high, thus, if failed,
    we have to go back to the very first process of building the
    prototype as it would be gone as a result. 

    To produce even better products, it is desirable for the craftsman
    to refine the resinous prototype before building the silicon mold
    between the processes 3 and 4 in the Figure 3. 

    MODIFICATION OF RESINOUS MODEL BY STEREO LITHOGRAPHY 

    1. Inaccuracy of the Size in the Vertical Line When a ring is made by
    Stereo Lithography, though the distortion in size on X- and Y-axes are
    negligible, approximately 2% of distortion (shrinkage) in size can be
    seen on the Z-axis. This, however, can be fixed by the CAD data. 

    2. Issues Regarding Offsetting In Stereo Lithography, since a laser
    is directed along the targeted lines, the resin is enlarged by the
    width of the laser plus alpha. Though Unirapid is equipped with an
    offsetting function to modify such enlargement, it proved
    unsatisfactory. We have learned from experience, however, that we
    don't have to do anything about the data itself as such enlargement
    would be offset by the polishing to be done to remove the gaps on the
    surface. When it comes to the inside of the pipe, however, as we
    cannot do the same, we had to modify the original data to a great
    extent. 

    3. Gaps on the Surface of the Resin Unirapid is capable of building a
    model at the pitch of 50f=CA, but taking into account its building
    speed, we most of the time set it at 100f=CA. Therefore, gaps are
    created on the surface at intervals of 100f=CA. These gaps are filled
    by thinly applying the UV-cured resin that is made a little harder
    than normal to prevent it from dripping away. 

    INTRODUCTION OF MMII 

    Since February of 2000, we have started to use an inkjet wax
    modeling system called MMII, manufactured by Sanders Prototype, Inc.
    We are the first to use it as a Japanese jewelry manufacturer. But
    yet, as a result of careful testing on the machine for well over 3 and
    a half years, including the days of its predecessor, 6PRO. The
    advantage of Model Maker ?U is to be able to reproduce a jewelry to
    precise measure. And because the quality of material is Wax , it is
    possible to do casting with Lost Wax Process. And we have found the
    system's following shortcomings: 1.Building a model takes a long
    time. 2.The material of the model is so fragile that it cannot be
    carried around as a sample. 3.As it requires precise .STL data as inpu=
t
    data, data modification takes a long time. Since we can produce models
    using the Stereo Lithography apparatus that are free from the factors
    1 and 2 above, it makes perfect sense to have both types of machines. 

    COST AS AN OBSTACLE 

    Generally speaking, the reality was that the prototype made by hand
    was cheaper than the one made by Rapid Prototyping. We had overcome
    many cost-related obstacles making various kinds of efforts, but
    under the circumstances where hand craftsmen themselves had a hard
    time finding jobs due to slow business, we had few orders coming that
    requested a new manufacturing technique. 

    In order to boost the orders, simply putting the traditional designs
    on the Stereo Lithography line would not work, and we had to create
    designs unique to the computer and which would not be worked on by the
    craftsmen. It was imperative to develop products that could only be
    created through Rapid Prototyping. With the idea that this was not
    only a problem for one company, but for the jewelry industry as a
    whole, we began to appeal to the industry at home as well as abroad,
    which culminated in holding the Rapid Prototyping Jewelry Design
    Contest where only designs unique to Rapid Prototyping would be
    displayed. 

    HOLDING THE FIRST RAPID PROTOTYPING JEWELRY DESIGN CONTEST 

    There were yet many problems to be solved, such as how to call for
    entry works, who should be the judges, what should be the prizes,
    etc., because holding a design contest was totally an unknown
    experience for a manufacturing company. 

    We then started to hold seminars for the designers to educate them
    as to what Rapid Prototyping was all about and what kind of designs
    were suitable for Rapid Prototyping. On a different note, we learned
    that there were some people who were impacted on by this contest. For
    instance, a certain design school put pressure on us to rethink about
    the contest. They used to make money out of the tuition for preparing
    their students for some contests after having them apply for them, but
    this time they did not know what to do about teaching as the teachers
    themselves did not know what to do for it. 

    Under these circumstances, however, we had 174 applicants and 24
    designs were chosen for production and put on display as metal
    products. The announcement of the winners was made at International
    Jewelry Trade (IJT) Fair held at Ariake Big Site from January 27 to 30
    in 1998. During such period, 537 votes were cast and decided on the
    Grand Prix and other winners. We exchanged cards with about 400
    participants and the contest came to a close with great
    success.There is no doubt in my mind that this contest increased the
    number of people who now understand what Jewelry CAD and Rapid
    Prototyping are all about. 

    INTRODUCTION OF SOME PATTERNS 

    We have analyzed the winning works and classified them into some
    categories to find out that the designs that follow are the ones that
    fully take advantage of Rapid Prototyping; the pamphlet with the
    information was made to be given out to those who attended the
    contest: 1.Openwork design that is very difficult to be made by hand
    2.Shapes that cannot be made out of rubber cutting 3.New shapes that
    have to be produced a couple of times to be tried on to get the feel
    4.Repetitive patterns made out of expansion and contraction of the
    same shape that fully take advantage of CAD's unique features 5.Pipes
    with graduated shapes that are difficult to be made by machine
    processing 6.Designs that intentionally take advantage of the gaps
    made unique to production by Stereo Lithography 

    SECOND RAPID PROTOTYPING JEWELRY DESIGN CONTEST 

    Following last year, this year too, we held the Second Rapid
    Prototyping Jewelry Contest. This year, we made a proposal to take
    advantage of the features of Stereo Lithography, Usually, the first
    meeting with the client takes place when we have prepared a prototype
    that is hand-made based on the given drawing, which is something like
    a rough sketch. In case it is found unsatisfactory, we have to modify
    or remake it until it would be accepted repeating the same procedure
    again and again.Therefore, when the final product is made, such
    processes would leave many unused prototypes. In order to avoid such
    waste, it is beneficial to use Stereo Lithography along the way to
    produce resinous models for checking purposes, but that has not yet
    proven to be as effective as such models are so different from the
    real ones in some aspects such as: 

    1.The color of the resin is either green or white, which is
    different from the real one. 

    2.The resinous model, by nature, is made slightly bigger, thus has
    thickness different from the real one. 

    3.It does not carry a gem. 

    In response to that, we have made a new proposal that we produce a
    resinous model by Stereo Lithography with a gem and colored with a
    real touch, for which we have conducted a survey in the industry as to
    how well it would be accepted.


____________________________________________________________________
T h e   O r c h i d   L i s t
Open Electronic Forum for Jewelry Manufacturing Methods and Procedures
____________________________________________________________________
Orchid FAQ:
~ http://www.ganoksin.com/orchid/faq.htm
Orchid Archives:
~ http://www.ganoksin.com/orchid/archive
Orchid Galleries:
~ http://www.ganoksin.com/orchid/gallery.htm
Invite a Friend:
~ http://www.ganoksin.com/invite.htm
____________________________________________________________________
Tips From The Jeweler's Bench - Article Archive
~ http://www.ganoksin.com/borisat/tip_sear.htm
The Jeweler's Selected Bibliography List
~ http://www.ganoksin.com/jewelry-books
Buy Orchid Jewelry:
~ http://www.ganoksin.com/shop
____________________________________________________________________
-Unsubscribe:
-Email: orchid-request AT ganoksin.com Body=unsubscribe subject=blank
____________________________________________________________________