Nearly two years ago, KiwiMill built a model of a five ton FMTV armored cab truck model with a specialized medical hospital payload. The model was 1/10th scale with the truck about 36″ long. It was completely hand-built for trade show use, with a brass frame and numerous brass details. The cab had separately applied bolt head and hinge details on laser etched acrylic armor panels.
Recently the model shop was asked to make a second FMTV truck, in 1/20th scale. Having acquired a 3D printer during the interim, KiwiMill approached the build somewhat differently the second time around. Many detailed parts that were built by hand originally, were drawn on the computer and made with the Objet 3D printer, precisely and quickly. Soldered brass was still used for strength and longevity. The fabric tent design was altered a bit as well.
There is no one right way to make a scale model. Approaches vary depending on the materials and fabrication methods available, as well as the particular preferences of the model maker. Specific client requests may factor in, and of course, budget and time constraints. Skilled model makers adapt and adjust to new technology, continuously honing and improving on their techniques.
Something that doesn’t change in the profession: the purpose of the scale model will always drive the fabrication method and materials used, while the quality of the finished product will determine if the chosen methods were successful.
At KiwiMill we use 3D printed parts to make some of our models, depending on the design and purpose of the project.
For a recently made MATV military vehicle, the doors were 3D printed out of plastic with handle, hinge and window details. The part was grown over night in the 3D printer, taken out and cleaned up.
The part was then primed, painted and given additional details.
Here is the door on the completed MATV vehicle. The printed part blends in with all the other materials that were used to complete this model. Our model maker chose soldered and braised brass for most of the model for the strength and endurance necessary in a trade show piece.
Our model makers built a Tactical Airport Surveillance Radar model series for ITT. This particular design is called the TASR-2020. Using photo-like images for reference, the majority of the pieces were made out of brass for strength, beauty and longevity. The CNC mill was used to cut the brass parts which were then soddered together. The fixed location unit was built mostly of styrene, which is a more flexible, durable material than plexiglass. The radar dishes were motorized to attract attention at trade shows.
The Patriot MIM-104 is a surface-to-air missile (SAM) system used by the United States Army and many other nations. The prime contractor for this system is Raytheon. You can read more about this system here.
This scale model was built mostly from scratch with one exception. The cab and chassis are a die-cast model that we used as a starting point for the truck in the pictures. When a high-quality mass-produced model is available in the proper size, we will often use it as a starting point for out model. Not only does this save a lot of time, a mass-produced kit often has small, high-detail parts included that would be cost-prohibitive for our customers. When a model is mass-produced (in the 10,000s or 100,000s) the small details can be injection molded. The injection molding process has high up-front capital costs but low per-piece costs for large runs.
The tires were designed in CAD and then output to our in-house rapid prototyping machine. They were then molded in RTV silicone and cast with urethane resin.
We used 3D CAD geometry supplied by our customer to design and fabricate this model.
More than 50% of the parts on this model were drawn in CAD and output to our 36″x24″ laser cutter/engraver. We use this not only to cut the shapes we need in various plastics, but also to add details by engraving the surface.
Small parts, including the hand rails and round rods are made of brass and are often brazed or soldered for strength.
Structural parts of this model such as the trailer chassis are made from brass to create a strong base for the rest of the details.