RE: [rp-ml] Design for (Rapid) Manufacturing

From: David K. Leigh <>
Date: Thu Mar 12 2009 - 16:45:42 EET

"Lets face it, the whole concept of RM is a marketing scam."

I will agree that there are RP manufacturing companies that are
rebranding their product in an attempt to get more market share and
improve the bottom line, but just because that is being done does not
support your argument.

There are many manufacturing processes, and you cannot adequately lump
every manufacturing process into the same category. The reality is that
there are currently a limited number of rapid manufacturing applications
with an increasing interest in developing new ones.

Several real examples:

Invisalign - use of SLA technology to aid in thermoforming. The SLA
parts are not the whole product, but are used as part of the
manufacturing process.

Hearing Aids - There is no argument you can use to say that the hearing
aid shells are not "manufactured." In the final assembly, there are
electronic components, circuitry, batteries, etc. . . all subject to
their unique manufacturing method. When assembled and tested in a
traditional manufacturing system, components made from RP are used.

Aerospace - There are components on both military and civilian aircraft
that have from traditional RP methods. While the volumes are not huge,
the total number of components are in the 1000s.

Face it, not one technology owns the term manufacturing. The examples
of manufacturing are too numerous to list and each have their place in
the production of end-use parts.

David K. Leigh


Harvest Technologies | Rapid Prototyping and Production Services

1000 Industrial Park Rd. | Belton | TX | 76513

Phone: 254.933.1000 | Fax: 254.298.0125 | "Where Innovation Takes Shape"

-----Original Message-----
From: [] On
Behalf Of
Sent: Thursday, March 12, 2009 12:13 AM
To:; Warner, Pat
Cc: Joe Kerer
Subject: RE: [rp-ml] Design for (Rapid) Manufacturing


I think we do agree, but there is the issue of terminology. 10 parts is
prototyping, not really manufacturing. Your case is one of the rare

Technically, one could claim that making 1 part is "manufacturing" but I
doubt that many MFG. Engineers invision themselves sitting and
contemplating how to build 1 part or 10 parts, or 100 parts for that

In many businesses a few hundred parts is "prototyping". When we look at
the RP industry, for the most part, it is not really even "prototyping"
as far as many industries are concerned. It is "model making". It still
has its place, and is a good tool, but it is not a "manufacturing

Prototype, and model are 2 entirely different things in many industries.
Look at the automotive industry for example. A model refers to clay or a
non functional mock up. A prototype is essentially a fully functional
vehicle with most parts made of the materials they will be made of in
production, but without the expense of production tooling. In aerospace,
a pilot can fly a prototype, but would not be able to fly a "model".

Lets face it, the whole concept of RM is a marketing scam. The fact that
there are anomalies whcih allow the technology to work are great, but do
not change the marketing hype and scam. Isnt it odd that the 2 biggest
player in the RP industry simply renamed their product line to catch the
wave of RM


--- On Mon, 3/9/09, Warner, Pat <> wrote:

> From: Warner, Pat <>
> Subject: RE: [rp-ml] Design for (Rapid) Manufacturing
> To: "" <>
> Cc: "Joe Kerer" <>
> Date: Monday, March 9, 2009, 7:19 PM
> Whilst I do see where you're coming from I can't say
> that I agree with you.
> RM is cost effective if the batch sizes are small enough. I
> build parts for use on our race cars using SLS, and as the
> batch size rarely exceeds 10, RM is a perfect fit for us.
> Tooling for such low volume would be ridiculously expensive
> and the lead times involved prohibitive. On the odd occasion
> where batch size has been up in the hundreds, I've still
> managed to manufacture parts in-house significantly cheaper
> than outsourcing to injection moulding.
> Aerospace companies are putting parts on military aircraft
> every day. I'm not sure that I could consider parts used
> on fighter aircraft as joke products. They obviously pass
> all the requirements for the product, and if it wasn't a
> cost effective way of producing the parts, I'm pretty
> sure they'd be doing it another way.
> Pat
> ________________________________
> From:
> [] On Behalf Of Joe Kerer
> Sent: 09 March 2009 22:11
> To:;
> Subject: Re: [rp-ml] Design for (Rapid) Manufacturing
> The best way to design for RM is to put something into your
> design that is going to make it extremely difficult to
> manufacture the products using more conventional means.
> Lets get real. A good designer designs for manufacturing,
> not RP. RM (RP) should only be used in rare occasions, as
> this is generally not a good manufacturing method.
> Look at many of the parts that the RP/RM manufacturers are
> showing as RM parts. They are mostly a joke, as they can be
> manufactured via other methods with better and cheaper
> results.
> Joe
> --- On Fri, 3/6/09, William Watson
> <> wrote:
> From: William Watson <>
> Subject: [rp-ml] Design for (Rapid) Manufacturing
> To:
> Date: Friday, March 6, 2009, 2:11 PM
> RP-ML:
> I was recently asked by our local IDSA chapter to write a
> short note on designing for rapid manufacturing processes.
> Although there is a lot of documentation on design
> constraints for other manufacturing processes (injection
> molding, sand casting, et al.), there is little help for
> designers in the additive fabrication space.
> I thought I would open this conversation up to the RP
> community with the hope of finding more help for the
> designers looking for better prototyping guidance as well as
> developing support for accepted DDM constraints.
> The article below was written for the industrial designer
> with little or no experience with rapid manufacturing.
> Obviously there is much more detail and depth than I
> covered. Hopefully this is a good place to start.
> The original can be found at:
> Here is the text:
> Design for (Rapid) Manufacturing
> Rapid Prototyping (RP), Additive Fabrication, Direct
> Digital Manufacturing, 3D Printing are just four of the many
> different ways to describe the twenty-two -year old industry
> based on technologies that build parts up, layer by layer.
> For the designers new to the technology, the promise is the
> same:
> Everything drawn in 3D CAD can be sent to a 3D Printer.
> If only product design was that easy. When your design
> process involves rapid prototyping, knowing about the
> materials and process can improve the outcome of your
> prototype.
> There are two equally false thoughts about prototyping
> materials:
> * RP parts are super fragile and super expensive -
> * RP materials come from "unobtainium" and are
> a perfect match for all designs and assemblies
> Although the first notion was probably true ten years ago,
> things have improved dramatically. Materials are stronger
> and better mimic the engineering polymers intended for
> production parts. Also, lower cost processes have reduced
> the overhead of many suppliers. For many processes, ordering
> a second piece only adds a fraction of the cost of the
> first. Since your marketing manager is going to keep the
> first model, might as well order two so you have one to use
> to communicate with engineering and manufacturing.
> Of course, the thought that RP machines can make everything
> is equally false. If your design includes sheet metal,
> expect to make some thickness changes before sending the STL
> file to the model shop. Many assemblies incorporate multiple
> materials to optimize the design for strength or weight. Do
> not expect one RP material to cover that very wide range of
> material properties.
> So, what is a designer to do? First, think about your
> design and product development goals. Then pick a
> prototyping strategy that best meets those goals.
> General design considerations:
> * When Outsourcing
> - Match your design with the right process
> * Small medical device? SLA
> * Color concept model? Z Corp
> * Over molded plastic/rubber? Objet
> - Be realistic about lead times
> * Start to finish with shipping time, outsourcing
> takes a week
> * Give your supplier a heads up when projects are on
> the way
> - Understand cost and time drivers
> * Material Volume
> * Build Envelope
> * Post Processing
> * In House 3D Printing
> - Know the strengths and limits of your process
> * Modify the design to make post processing easier
> * Know when to use assemblies, and when to manually
> assemble components
> * Use hollow or sparse builds to minimize costs
> - Understand support materials and post processing
> - Determine how to make the build more efficient. What
> drives time?
> Just like most other manufacturing processes, RP
> appreciates good design. Simple rules like constant or
> similar wall thicknesses help make growing and processing
> the parts much more efficient. Cantilevered beams often need
> support, and sheet metal features need to be thickened. Most
> importantly, using good design sense and understanding how
> your parts are made will help you make better designs in
> less time with less money
> Bill Watson, IDSA is the managing partner of Anvil
> Prototype & Design
> (<>),
> a Z Corporation partner and RP service bureau based in
> Charlotte, NC.
> Bill Watson
> Anvil Prototype & Design
> 4101 Stuart Andrew Blvd. Suite F
> Charlotte, NC 28217
> Voice: 704-527-8171
> -------------------------------------------
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Received on Thu Mar 12 16:46:49 2009

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