The day finally comes and you have your invention prototype in your hands and, well, you simply are not happy with the outcome. In fact, you are a bit disappointed.
The decision to have a prototype made before continuing into the manufacturing process proved to be the right choice. Why? You have a prototype that you have tested and now realize that it is incorrect as it does not fit or work as you originally intended or hoped. However, rather than spending money on parts and tools for manufacturing or larger scale production, you have gained valuable insight from your prototype to make the necessary modifications without wasting too much time or effort.
The cost of having a prototype made is minimal in comparison to the cost of having to restart the manufacturing process over with new tools, not to mention having to pay for potentially rejected production parts. The money adds up quickly and, as an inventor, every penny counts from conceptualization and design to production and marketing.
I generally suggest getting at least two sets of prototypes made per new product. The first set of prototypes should be developed during the concept phase of the design process. You do not need to have a final manufactured drawing to have a prototype made, nor do you need to have a finalized set of designs. The idea for this first prototype is to decide if the overall size, features and functions are what you want or intended as based in your original concept or idea. This first prototype serves is the initial prescreening process to determine any modifications that can be efficiently and effectively completed prior to completion of the design. Overall, the money that you spend on having a prototype made after the concept phase is marginal. Consider the alternative: what if you did not have a prototype made and you discover that, at the end of the design phase, the design is incorrect or unusable? A prototype is a necessary expense to ensure that your product meets your specifications in addition to ensuring its overall usability and design. Mistakes are far easier and more cost-effective to fix when they are caught early, rather than later, in the process.
Once your initial prototype is completed, if you are happy with the size, features and function, then continue with the design as planned. Always remember that it is vital to discuss all of your prototype requirements with the design company before the design process begins. The designer will need to spend some time saving files in a variety of formats and then send them to your suppliers, possibly making small modifications to the design to suit the prototype methods. This extra time for the designer may need to be included into the initial cost of the design so always discuss the prototype up front to ensure that the process and the budget reflects the plan accurately and completely.