Turning Ideas into Products: Expert Tips for Invention Prototypes Part 4: Production Prototypes

During the last installment of this series (see Part 1 here), I talked about the use of proof of concept models to demonstrate the feasibility of an invention before the inventor takes on the expense and effort of creating more realistic prototypes called production prototypes. Once the feasibility is proven, the next task is to transform the invention from concept into a real product. This final product would need to look good on store shelves, engage end users, and hopefully be manufactured and sold for an attractive price.


As we get closer to the desired end result, we are looking for an accurate replica of the final concept that we intend to produce. We call this product replica a reference prototype.  At this stage we need to show the function, aesthetic design and manufacturing method (including all components) of the final device. We need to be as close as possible to the real thing in order to clearly define what is going to be produced. We need to give the developer the confidence to make the capital investment to bring the product to market. This goal is achieved through an iterative process of refinement –with the creation of progressively more refined prototypes next on tap.
Production prototypes are made through small-scale prototype production methods (detailed in Part 2 of this series) as opposed to large-scale mass production methods. The key here is that setting up large-scale production almost always involves an upfront capital investment in equipment, such as injection molds, which can be very expensive. Once this equipment, generically called “tooling,” is created, it can be very expensive and time consuming to modify. This is why it is so important to get the design as close to correct as possible before making the tooling. Depending on the complexity and size, prototypes can cost tens of thousands of dollars. In the world of non-electric consumer products (like kitchen gadgets and hand tools), many items end up costing under $3,000 to prototype, with some pieces even in the low hundreds.

There are three key aspects of the product design process that will be refined through iterative prototyping: function, aesthetics and manufacturability. These are listed in the order that they should be addressed. However, many times it makes sense to develop all three examples simultaneously since the process of resolving one aspect is directly linked to the others. You want to get as close as possible with each prototype in order to minimize the number of prototypes that need to be made in order to keep costs and timeframes under control. To make this level of prototype (assuming we are talking about a typical plastic and/or metal consumer product) you will need 3-D CAD files of the design. These files are created through an industrial design process in CAD software.

During this phase of the design process, each of the components that make up the final device will need to be worked out. It’s time to consider final shapes, how they all connect to each other, what they should be made of, what they look like, and how they will work together as a final product. At this stage it is also important to make sure that you have created the desired functionality and look for your product while taking into consideration that you must achieve a final price point that customers are willing to pay.

The pieces you’ll need as it relates to producing mechanical components are the digital files that can be loaded into either a CNC mill or 3-D printer in order to create each component. Once you have these files, you can send them to a prototype fabricator (like Trident) to get the parts made by the appropriate method. Once the parts are produced, the prototype will need to be assembled and tweaked until it works as well as possible. Remember that it is extremely important to note each little tweak you have to make to get the prototype to work so that the next prototype can include that learning.  If the device is electronic, of course the circuitry will need to be developed too.
In some instances, certain aspects of your design can be prototyped separately as it might be cost prohibitive to have a so-called “works-like/looks-like” prototype. This is especially true when dealing with material strength issues, because sometimes it is easy to prototype the way something will look, come together and work, but not with the strength of production materials. Therefore, it is common to finish with a prototype that is close to perfect in every respect except that which can be proven either through simple functional models or engineering math.
Another example where this is often true is with electronics. It is often much easier to prototype circuitry at a larger size (on breadboards) and then move directly into production at the final size. This is especially beneficial when dealing with simpler devices.  An inverted example of this could be with larger items like transportation and massive structures, where scale models can play an important role.
Production prototypes play a central role in the product development process.  Proof of concept models may show that an idea is feasible in the general sense, but no one would ever buy one at a store. The concept has to be turned into a product and that process usually takes a number of iterations and rounds of tweaking (typically at least 3). In the next installment in this series, I will discuss how to use the prototypes you create to learn as much as possible in order to optimize the outcomes for the prototyping process.


Part 1 - Expert Tips For Invention Prototypes - Part 1: Terminology
Part 2 - Expert Tips For Invention Prototypes - Part 2: Prototyping Methods
Part 3 - Expert Tips For Invention Prototypes - Part 3: Proof-of-Concept Prototypes
Part 4 - Expert Tips For Invention Prototypes - Part 4: Production Prototypes
Part 5 - Expert Tips For Invention Prototypes - Part 5: The Iterative Process
Part 6 - Expert Tips For Invention Prototypes - Part 6: Making A Million Dollar Product

Also, check our our Inventor Information Section on Prototyping Your Product or Invention


Chris Hawker
Trident Design LLC
Advice for Inventors Blog
- InventorSpot.com

Chris Hawker, Founder of Trident Design, LLC is an idea guy. Chris has spent the last 20 years inventing, developing and selling innovative consumer products in a variety of industries. Chris has brought numerous products to market through a variety of business models including licensing, private label manufacturing, marketing, distribution and more. To date, Chris is probably most well known for the PowerSquid, licensed to Philips—an innovative, award-winning, and commercially successful power strip.