As a designer of a part that will be die cast, you must switch gears mentally when it comes to prototype casting. Do not assume that everything will be accomplished in the casting process. The question that isn’t asked may be the one that trips up the project.
Cost is always a factor when it comes to prototyping. You know you need to produce a certain number of prototypes to test your design. Where do you draw the line on quantity? Is ten castings the right number or should you consider ordering fifteen or twenty just to be safe? Sometimes the limitation on quantity is drawn so tight that there aren’t enough parts to go around for proper testing and evaluation.
Sometimes people make choices that appear to be right but in retrospect find that the choice was made for the wrong reason. Over the years I have witnessed people choosing the wrong prototyping technology in an attempt to shorten their prototype lead-time.
Let us assume that the decision has been made that a prototype will be needed before releasing a part for production. So the next question is what type of prototype will you need? Or to phrase the question another way, What is the primary reason for creating a prototype?
A hog-out may, in certain situations, be a quicker way to create a prototype that will ultimately be die cast. But, like any other metal prototyping process hog-outs offer distinct advantages in certain cases and disadvantages in others. The following are simply guidelines to help the designer make a decision as to which process to choose for his specific situation.
There is no single prototyping process that is right for every application. But for every application there is a prototyping processes that is the most optimum solution. The critical question to ask yourself is: “What is the primary purpose or use of my prototype?”
Virtually all prototypes are exceedingly time sensitive, some more so than others. It is important for the prototype supplier and design engineer to talk about time lines early in the developmental process. Holding back releasing the prototype build until the last minute, for whatever reason, is not beneficial to a successful prototyping process. The earlier you can bring the prototype supplier into your confidence the better for everyone.
You are approaching your prototype build and your casting design is not complete. How many of you have been in this situation?
Is your prototype quantity requirement 10 pieces or is it 250 pieces? Is it 10, and then 250? Is it 10 and then maybe 250? It is helpful for you to try to determine this, and to share this information with your prototype supplier at the quoting stage.
An example might be the designer of a structural component who went through a prototype program and initial prototypes failed in mechanical testing. A subsequent redesign yielded parts that performed well. The designer however, had prototyped the initial parts in an alloy and process that was not representative of the eventual production process.
