We talk a lot about iteration here at Fictiv because it’s the foundation for lean hardware development and lean hardware development is the key to bringing successful hardware products to market.
Iteration refers to the cyclic process of refining a design until you’ve achieved the established product requirements, outlined in your PRD (product requirements document). While the process of hardware design has been historically sluggish, by leveraging both digital and physical tools as part of an iterative prototyping strategy, you can in fact achieve lean and efficient hardware development.
In this article we’re going to review the basic principles of iterative hardware design between digitial and physical mediums to help you develop better products, faster.
Digital Informs the Physical, and Vice-Versa
Throughout the process of moving between digital and physical mediums, each step informs the other.
For example, when a structural analysis concludes that a certain feature is unfit for the amount of bending anticipated during use, this information is fed back into the CAD design, and the feature is made stronger until analysis can validate its structural integrity.
Rapid prototyping using different fabrication tools is a part of this cyclic design process and the information gained from a physical model is essential to the development of a well-designed product.
Here are just a few reasons why physical prototyping is a key element in the hardware design process:
Spatial relationships - Designing with digital tools has immense value, but it’s difficult to truly visualize how large an object is on a computer screen; holding it in your hand makes it easy.
Physical = tactile - After visually designing a product with digital tools, adding the ability to touch or even smell the product further informs the design process. Textures and grips, for instance, are designed for the tactile nature of consumers, so actually feeling these features is important.
Assessing functionality - Do the parts fit together? Does it perform how you expect it to? Beyond designing the form of a product, functionality is equally as important and requires a physical model for testing.
Steps to Go from Digital to Physical
Here are the basic steps involved in moving from a digital model to physical prototype:
1. Prepare Your Digital Model
Depending on the type of fabrication, your model will need to be exported as a certain type of file. Parts will need to be exported separately if your design contains assemblies.
STEP files are most common for manufacturing because they contain a great deal of information while maintaining a relatively small file size. STL is the filetype commonly associated with 3D printing and is used solely for that purpose.
If you’re going to export your digital model as an STL file for 3D printing, make sure you take the steps for proper exportation.
Most people cringe at the very thought of documentation, but it’s a vital part of any vigilant design process. Being able to clearly see what was changed from previous versions, not to mention the ability to actually open any previous versions, is important if you ever need to compare designs.
Here’s a simple rule to use when documenting versions:
Whenever the design crosses the door (i.e. when the file is emailed to someone for quote, collaboration, fabrication, etc), the version number (or letter) is increased and at least one sentence is written about what was changed from the previous version. The more info, the better, if not for the current design then for lessons learned and future designs!
We’ll go into more detail later on in the Hardware Guide around key principles for testing your prototypes, but keep in mind that this is the final step before returning back to digital from physical.
During the testing phase, you might be assessing the functionality of your snap fit designs or other tightly toleranced components, for example. Or you could be testing the strength or stiffness of a component to see if it can withstand a certain amount of weight.
In this part of the iterative process, you test, assess, document, and then implement the necessary changes back in your digital model.
In order to iterate most efficiently on your hardware designs, you need to go from digital to physical as quickly as possible.
Both digital and physical tools are equally important in the hardware design process, so use each tool according to its strengths, and create a plan early on to schedule your design iterations between the two mediums.