The Art of Making a GMP Diecast Model
Go behind the scenes and learn what it takes to create someone's "dream" car
One of the most frequently asked questions in the die cast hobby is how a diecast model is actually made. It's a question posed at trade shows, on the phone and in emails. The process is long with much attention to detail being paid at every corner of each project. The entire process can take over 18 months to execute from concept to product.
So how is a vehicle selected? It can be a whole host of factors that make a car the "right" one to do. The process starts with a brainstorming session. All the team members gather, they review collector requests, surveys they might have conducted, historical significance, images currently out on the market, trends, past successful models and a whole host of other factors that may decide what the next model might be. Discussions may also include studying variants of the same car so as to maximize the use of a single tool. Tooling is the expensive part of any die cast project. To make the best possible use of a tool needs sound judgment from the start. Initial discussions on licensing begin at this stage, as this is a crucial facet of development. No license = no model!
Once an image is selected, the team has to locate a pristine sample of a car. Sometimes this can be difficult, especially if the car is a very limited production version. One problem with restored cars is that you need to look closely to see that it has not been over-restored or updated. Sometimes this is unavoidable, as some racecars have had mandatory safety updates that have changed the original configuration and specifications. Other times pristine samples are not available, so you have to go with a car under restoration. In some cases this option is better as the car is "original" and has not been over-restored.
Once a car is located, the fun begins. It may take several days to fully document a car. Documentation involves measurement, photography and authentication. It usually takes 300-400 detailed pictures to fully document a car. Details specific to a make or model need extra attention. Detail picture of textures and patterns are also essential. This involves close-ups of seat patterns, grain textures, headliner detail, carpet textures, dash textures, engine metal textures such as those found on cast parts versus a polished part.
Details such as dash knob wording, radio and gauge faces also have to be photographed and scaled so they can be reproduced later as art film. If color selection has been determined, colors can be matched to color samples. Industry standards use, Munsell, Pantone or TOYO color match systems. Measurement is also very critical. Overall pictures will usually be shot with some sort of size gauge. This allows the model builder to scale his model appropriately.
GMP's China factory will send a staff member to accomplish this and sometimes the process itself becomes quite innovative. In order to properly document a chassis, the photographer will lie on a creeper and will systematically roll around under the car, which is on a lift, and shoot many pictures of the underside. Once the shots are developed they can then "assemble" the various prints and make a complete chassis. If certain parts prove difficult to photograph or interpret, a quick sketch with hard measurement is indicated. For instance, a complicated exhaust system may require more than just a photo.
Once all the information is gathered, it is reviewed and organized. Color selection may be finalized at this point, if it has not been made so far. A "product description" is drafted which tells the factory what features the model should have and what materials should be used, where. This will also determine a rough cost associated with the project. Once all of this is in place and approval are rendered, the project takes on legs.
Body Shape Model
The first step is the hand made body shape model or "body buck." This is a handmade model that depicts the outer shape of the car. Someone who will pick out any design flaws reviews the body shape model. He then will offer suggestions on corrections. A body shape model can cost anywhere in the neighborhood of $10,000. The size of a body shape model is roughly 1:12 scale.
As the body shape model is made a duplicate body is also made. This stage is the prototype stage or "pattern." This pattern has all the working features of the model and will be used in the making of the steel tool. The prototype is very important as most issues need to be resolved at this stage, otherwise later revisions can be more costly. It is important to note that every part of this model is hand made.
These models can cost up to and beyond $50,000 depending on the complexity. Once the review is complete, a booklet is put together with the comments and extra reference material and then shipped back to China. Careful selection needs to be made, as any error in this phase will require extensive repair. The prototype is then pantographed, which is a process that reduces the part into the appropriate scale. The model enters the tooling stage where steel for the tool is actually cut. During this stage the prototype is actually destroyed by the process required to make the tool.
Parts are precisely measured and tooling steel is cut. This hard tooling will become the mold that makes thousands of models. As you may recall, early on in the process a product description was written and a tool plan was made. This defined what parts would be die cast, plastic or PVC. Parts would then be grouped in the tool specific to the material being used. Tooling is the most expensive part of the die cast process. Tooling costs can go over $225,000!
A first shot is exactly what the name implies, a first shot of parts from the tool. Much like a model kit, parts emerge from the tool and are loosely assembled. Corrections need to be made at this stage and any fit issues need to be resolved. If the prototype review was extensive and thorough, many of these issues will be minimized. If not, there could be extensive reworking of the tool. Once refinements are made, a second shot is run. Textures and colors need to be finalized at this stage. Artfilms may also be submitted for review. These films will show gauge detail, and any interior, under hood or exterior art that the model will have. Once all details have been finalized on the tool, the steel is hardened. Now the models are ready to be mass- produced. During this stage, photos for ads and collateral booklets can be developed using a decent painted sample, collateral booklets are written, packaging and box art is completed.
Several additional shots may be run to fine tune the function of all features and the fit of all parts. Sometimes, using an old trick, models are painted white. White has a tendency to make all body panel gaps more evident. This is better demonstrated on models that are 1:24 or smaller.
Once all issues have been addressed, and this may take weeks of email exchanges, the tooling can be hardened and readied for production runs. Pre-production models are often painted and detailed. This stage also allows you to add and fine tune all mask spray operations.
This is what all the effort is about, the production run. Parts are cast, trimmed, buffed, primed and painted. Exterior artfilms are made into pad printing art and the bodies are tampo-printed. Tampo printing or pad printing is a process where a machine has a specific soft silicone pad. It dips into a plate with the design and paint, lifts and moves to a specially designed jig that holds a model precisely in place. The pad stamps the image onto the body. This is a quick operation and the machine's operator can move multiple car bodies or parts quickly through the process. Multiple colors will require multiple hits. Let's say you want to do a sponsor emblem that is red, white and blue. This will require three hits so that each component is correctly duplicated. This is the reason for the artfilm review. Each color is a layer of film and each color needs to be individually specified using the same color-coding system.
The Final Steps
The models are assembled, packaged and shipped to the USA via container ships. The trip could last a month. Sometimes factors like strikes and weather could delay the trip. Models are tested at the factory to withstand humidity and temperature. This helps them make the trip safely. One experience to share: once, at another company, a container ship hit a typhoon and containers were washed off the deck. Production had to be restarted to make up the lost shipment-especially since they were limited editions!
The models arrive at their GMP destination where they are either warehoused for later sales or immediately packaged for shipment to the collector. The die cast process is complex and long. It brings many people together so that a project can come alive in scale. For GMP, it's a true labor of love.