All posts by pam

Production Processes for Multiple Scale Models

Custom scale models are often one time only builds. Model makers are given an object, picture or design, they draw up the parts in 3D and set about constructing the item. Whether the finished product ends up in a museum, sales office, board room or trade show booth, it is often a one-of-a-kind model that won’t be repeated.

Occasionally, though, a model shop is given as assignment to make multiple scale models of the same design. Sometimes these are requested all at once, and other times a model shop will repeat models on an as-needed basis.

It is these types of projects that turn the model shop into a temporary production facility of sorts. A systematic approach is developed to create multiple parts in an efficient, orderly fashion. Using fabrication techniques such as casting, CNC milling, 3D printing and lasering, multiples of the same part are created.

When it comes time to assemble parts for duplicate models, jigs are designed. A jig is a tool used to control the location or motion of another tool. The jig’s primary purpose is to provide repeatability, consistency and efficiency.

Creating multiple scale models of the same object requires certain upfront approaches that would be unnecessary for a one-time build. Duplicate models are still custom-built, but fabrication techniques and production processes are controlled and streamlined in order to create a consistent product, over and over, in a reasonable time-frame.

Progression of a NASA Spacecraft Model

The following pictorial shows the progression of a NASA spacecraft model build:


From the NASA Magnetospheric Multiscale (MMS) Mission  website:

“The Magnetospheric Multiscale (MMS) mission is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration, and turbulence. These processes occur in all astrophysical plasma systems but can be studied in situ only in our solar system and most efficiently only in Earth’s magnetosphere, where they control the dynamics of the geospace environment and play an important role in the processes known as ‘space weather.'”

Honda Aircraft Site Model

site model

Just Shipped:  A  site model of the Honda Aircraft Headquarters, Research, and Production facility in  Greensboro, North Carolina, located at Piedmont Triad International Airport. This facility is home to the new HondaJet personal aircraft, scheduled for shipment in early 2012.

The site model, along with the aircraft itself, was unveiled this week at the OshKosh AirVenture Show .

The design of this particular site model was driven by our client’s request for exceptional attention to detail. To achieve this, our model makers were given  a multitude of data: aerial views, autoCAD drawings, PDF’s, ground level pictures and exact measurements for items such as:

  • air conditioning ducts
  • generators
  • HVAC units on the roof of the buildings
  • cooling towers

The scale of the model 1″:40′ was very small, which contributed to the over all impact of the finished product.

Take a look:

Can a Model Maker use Mass-Produced Parts?

Professional model makers are in the business of building (and sometimes designing) one-of-a-kind creations. Very occasionally, though, a model maker decides that fabricating a particular part from scratch is not in the best interest of the project. In these instances, an existing product might be bought and deconstructed to extract a commodity out (sometimes referred to as “kit bashing”).






These plastic wheels have been removed and reassembled from off-the-shelf toy trucks. They will be added to built-from-scratch trucks. The trucks themselves are not the main focus of the finished model. Ultimately this project will be a training model for a shipping company that would like to have table top practice at the real life task of loading and unloading pallets.

It’s uncommon to find preexisting parts, particularly in the right scale, for a custom model project. Internet searching has made it a bit easier to find a usable commodity. Sometimes it’s a smart choice for a project, and ultimately for the client’s budget, to include ready-made pieces in the construction.

Museum Models – Caretakers of the Past, Present and Future

museum model

Did you know that there are almost 18 thousand museums in the United States? Are you aware that zoos are classified as museums? The American Association of Museums (AAM) lists the  following  types of museums on their website:

  • Arboretum/Botanical Gardens
  • Art Museums
  • Children’s Museums
  • Historical House or Site Museums
  • History Museums
  • Natural History or Anthropology Museums
  • Nature Centers
  • Zoos
  • Science/Technology Museums
  • General Museums
  • Specialized Museums (such as Railroad, Military, African-American)

Did you ever wonder how they are funded? While many charge admissions, there are a fair number that are free-of-charge to visitors. Private charitable donations provide the largest percent of funding followed by admission charges (including gift shops and concessions), government funding (25%) and investment income.

For those interested in museum careers there are degrees offered in museum studies, historic preservation, public history and non-profit management. Of course museums require a host of services to develop, support and run their institutions. Things like  facilities management, public relations, institutional planning, retail services, membership & development, collections stewardship and human resources.

The most obvious feature of a museum is the exhibits themselves.  While some museums are known for their collections of original artifacts, many more use reproductions, display boards, dioramas, props, scale models, interactive kiosks and hands-on exhibits to educate and entertain their visitors. Exhibit companies design these spaces to maximize a particular museum’s goals, and model making companies are often called upon to create the actual objects that go in these spaces.

The  International Council of Museums (ICOM) defines these spaces as “a non-profit, permanent institution in the service of society and its development, open to the public, which acquires, conserves, researches, communicates and exhibits the tangible and intangible heritage of humanity and its environment for the purposes of education, study and enjoyment.

Model makers pride themselves on providing quality museum models that will hold up to the high standards of these institutions.

Scale Model of Innovative Shelter for Rapid Response

When response is needed quickly, SAIC’s Expandable Shelter System  (ESS) is the solution for military, homeland security, law enforcement and commercial use. It’s a self-standing, self-contained, rugged and secure entry shelter that transports readily by rail, ship, aircraft or vehicle. Shippable and stackable at 8×20 ft, it expands to 20×24 ft, with approximately 400 square feet of space inside. It’s a space that can adapt and reconfigure to multiple uses such as communications center, field kitchen, medical facility or sleeping quarters. Each unit allows for self-sufficient electrical power, climate control and satellite communications. Multiple units can be strung together.

KiwiMill was given the task of building the scale model for this superior-designed shelter system. The scale model was built in  1/8 scale using sheet metal, acrylic and brass hinges for the main body with the addition of ren board, ABS plastic, brass tubing and evergreen strips for the generator. The key feature of this model is its functionality. It operates much like the real thing, doors opening and the shelter expanding in the same fashion as the actual shelter.

Model with Working Parts

Our model makers have shipped out the asphalt plant model with working parts. Seven feet tall, with functionality, this model simulates the movements of an asphalt plant. Doors and chutes that operate in the real plant with hydraulic cylinders have been mimicked using 12v electric linear actuators. Augers and buckets in a real plant that run on gear motors have been simulated using miniature gear motors.


Welding as a Model Making Tool

model maker weldingOne fabrication technique that is not often associated with model making is welding. While styrene plastic and glue are staples of some model designs, many more are made out of metal for stability, longevity and appearance. One way to fasten metal model parts to each other is by welding, or a similar technique: soldering. While not every model maker is skilled in this trade, it’s helpful to have the training and equipment on hand in a professional model shop.

Welding is the process of bonding parts together by applying heat to two pieces of metal and melting them together along with a filler material to form a strong joint when cooled. Soldering is similar but does not actually melt the work pieces themselves, only the filler material between them which has a lower melting point, thus requiring less heat application.

Types of models that may need welding or soldering application vary. If a model needs to hold up to heavy handling by the client it might be considered a good candidate for brass, sheet metal or stainless steel. A more delicate material would not hold up to rigorous use.  As with most models, the purpose or intended use informs the materials and fabrication techniques involved.

Currently KiwiMill has two models in the shop that required welding. One is a large-scale model of an asphalt plant and the other is a model of an expandable shipping container. One of our model makers has apprenticed with another in-house master welder to complete these projects.

model maker welding

Architecture Is a Beautiful Thing.

architectural model

Most people can get excited about architectural models. Breathtakingly huge skyscrapers lit from the interior,  intricately detailed cottages with lift-off roofs, or lushly landscaped commercial developments capture attention. These types of models can be true works of art.

Besides being beautiful to look at, architectural models play an important role in society in general and development specifically. They are used to approve plans, raise funds, marketing and sales, as well as showcasing exceptional or historically significant design.

There are as many different types of architectural models as there are approaches to building one. Simple mass designs, in one solid color (usually white), semi-detailed studies with medium levels of texture, color and intricacy, all the way to museum quality finely detailed marketing models with landscaping as important as the architecture. The type of architectural model is ultimately dictated by its use in the business world, along with budgetary concerns of the client.

KiwiMill works closely with architects and developers to produce highly accurate, one-of-a-kind, finely crafted simulations of design in a time-frame that meets the needs of our clients.

What’s a Prototype Model?

medical prototype


It may seem oddly counter-intuitive, but often the quickest, least expensive way to make a new product is to first make something else – a prototype model.

A prototype model is a special type of model that engineers or designers use to test a product’s properties and function. Prototypes allow engineers to explore design alternatives, test theories and confirm performance all prior to starting production.

Early on in the creation of a new product, a series of prototypes might be designed, fabricated and tested, progressively refining the final iteration. It’s assumed that the initial prototype will have many changes made to it as feedback is given.

The prototype model is a learning tool above all else. Different types of prototypes serve different purposes, and provide specific answers to design questions.

Some prototypes are for proof of concept – they don’t attempt to simulate the finished product in any way. Other prototypes replicate the size, look or feel of the product using simple materials and are meant to be studied but not put to repeated use. Some are constructed out of sturdier materials and are expected to be withstand  rigorous  human interaction during the testing phase. Some prototypes are meant for visual fidelity only. They copy flawlessly the visual appearance of the product for use in photo shoots or executive review. A fully  functional, or working prototype would simulate the final product to the highest degree, or fidelity. This prototype would be for a final check before production began.

So why bother having a prototype instead of the real product? Simply put, a prototype will save time and money in the long run. Prototypes show potential investors or users an idea of what the product looks like in the earliest stages of development. Less expensive materials and manufacturing processes, along with simpler details and engineering, allow for more design options to be tested using prototypes before committing to the production stage. Identifying problems with design early on saves money. Having users test  different designs during the development cycle gives critical feedback that will likely result in a more marketable final product.

It’s cost-effective to make use of prototypes during the design process, and it need not slow the actual time down between the initial idea and it’s arrival on the market. It can in fact speed that process up.

Heavy Equipment Sales Model

If you have a large piece of machinery, heavy equipment vehicle or industrial process that you need to sell to customers you have to make choices about your marketing approach. Phone calls, email,  or face-to-face contact? Probably a combination of all three. A good website – interactive and informative – is imperative. Video testimonial, a detailed brochure and participation at trade shows might be useful.

One approach that is almost out of the question is hauling a huge, bulky piece of equipment to the prospective buyer and saying, “Look, here it is, and let me show you all of its outstanding features.”  It would be effective, but impractical when dealing with oversized products.

A sales model would provide that impact without the cost and logistical impossibility of the real product. Imagine having a detailed sales model of an excavator, a cooling system or a jet engine that travels with the sales team and can be displayed with ease in a variety of settings. A model reproduction of your over-sized product  will inform, impress and engage potential customers, giving a worthy return for your investment.

Building a Model from Scratch – A Model Maker’s Perspective

model maker

Most people’s perception of a model maker is someone opening up a box and gluing parts together.  This isn’t what we do here, there are no kits for what we make.  Building a model from scratch; that’s what we do, art in a three-dimensional form.  If an object is made of metal, we might make the model out of plastic; sometimes an object is made of plastic, but we might make the model out of metal.  The end result is the look of the model, and with paint generally covering the material, what’s underneath isn’t important.  The reason we use different material is either for strength or for ease of workability.  Plastic is much easier to shape and attach together than metal, but it can be weak; metal is stronger and more durable, but harder to work with.  All of these decisions are made based on the end use of the model.  If it is going to be displayed in a showcase in a corporate lobby, the finished piece can be more fragile, as the model won’t be handled.  If the model  is for a trade show, it will frequently be packed and unpacked, set up and handled.  Both of these uses steer us toward different assembly methods and materials.

The advent of three-dimensional computer graphics has definitely changed model making.  When we are fortunate enough to receive 3D CAD files from a customer, this definitely makes our processes easier, especially when complex shapes are involved.  Working from two-dimensional drawings is still common, many times full size devices are still constructed using them, and this all that is available to us. And, there are times when all we receive is a few photographs and basic measurements.

Just because a device is made from a thousand parts, a model might only be made from ten parts.  Here is where we look at the drawings and photographs to determine how we are going to construct the model.  The model makers here usually have different ideas of how to proceed at this point.  Often we get together and discuss the project with all kinds of ideas presented.

Although we do occasionally work with steel or aluminum, brass is the metal most often used in model making.  It is relatively strong, but is soft enough to machine easily and can be attached by mechanical means, soldering or brazing (similar to welding).  Plastic comes in many forms. The softer plastics, like styrene, are easy to work with, but don’t machine well (on the laser cutter it melts instead of cutting). ABS and PVC machine better but can’t be cut with the laser.  Acrylic is our preferred plastic for laser cutting. The laser allows complex shapes to be etched and cut easily and quickly.  Most models end up with at least some parts made this way, many architectural models are completely laser cut.  Occasionally we are requested to make multiples of a model, for this resin castings are often utilized. A master is made using various materials, and then a rubber mold is made to cast the resin in.

Yes, we do use glue.  But glue by itself often isn’t enough. Wherever possible we use mechanical fasteners, usually machine screws, to attach parts together. Both methods used together ensure a strong bond.

There are so many ways to make models, this is only a short overview of what we go through.  More insight can be gleaned from reading our blog as we endeavor to show you what we do here at KiwiMill Model Makers.

– Jim Otto, Model Maker

Making a Model With Working Parts

scale model working parts

working parts scale model

In the shop right now is a 7 ft asphalt plant model with working parts. Anything that moves in a real asphalt plant will be replicated on the model as well. It won’t actually function as in turning tar & stones into asphalt, but it will be nearly capable of doing so in miniature.

The client wants to demonstrate how the machine operates or how it is controlled. Doors and chutes that are moved primarily by hydraulic cylinders in a real asphalt plant will be demonstrated with 12 volt electric linear actuators on the model. Those parts in a real asphalt plant that move with gear motors – like augers and buckets – will have miniature gear motors on the model.

Our model makers create drawings in AutoCAD of the doors and chutes, in an open position and closed. That way the “throw” can be calculated, which is the amount of swing needed to open them fully. Then it needs to be determined what length actuators will best represent that throw. The working parts on the model need to be built and the actuators installed on them and tested for accuracy. An important factor to consider is whether or not the actuators can show on the finished model design, or need to be imbedded or disguised. In this particular industrial model, the actuators will be part of the visual presentation.

The gear motors are chosen for the model based on the scale speed necessary to make the parts turn. How much torque is needed? – what sort of load does the gear have to move? This will determine how powerful the motor needs to be. Generally if the part needs to move fast, less torque is required and if the part turns slower, more torque is called for. This particular model has a 218:1 gear ratio as the miniature motor needs to move quite a bit of mechanics.

Finally you have to tie together the different voltage strengths of the various actuators and gear motors into a controller that sits in the base of the model. This programmable code (located in a circuit board) will be the power source, or “the brain” of the working model parts. It will control when power is needed and where in the model to send it.

Description of a Model Maker

 model maker

David Neat,  master model maker, teacher and author in the UK, describes the essence of model making:

A model maker needs “a rigorous command of scale and knowledge of the varied materials and methods which will assist in achieving it.”

 Ok. A fairly ordinary description so far, but then he finds that elusive bit that elevates the craft into the realm of art:

A person invested fully in “the magic of simulation: recognizing the essential or fundamental in the appearance of things and reproducing it in the most effective and economical way.”