The Art of Making a GMP Diecast Model


 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.


The Concept
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!

The "Hunt"
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.

Documentation
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.

Prototype
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.

Tooling
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!

First Shot
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.

Pre-Production Runs
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.


Production
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.


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