The Art of Making a GMP Diecast Model
Go behind the scenes and learn what it takes to create someone's "dream" car
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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.