The True Cost of Prototypes

2018-09-27 | By Maker.io Staff

Whether you are creating a prototype for a project or a product, there are many hidden costs that you may not have taken into account. These range from all things software-related to all possible laws and regulations. In this post, we will take a look at a few of the different costs that may surprise/creep up on you!

Software

Most projects and products these days integrate some kind of microcontroller, and this nearly always results in programming. While most microcontroller manufacturers offer free versions of their IDEs and compilers, they may not be suitable for commercial applications. Microchip, for example, offers paid versions of their compilers, which provide better code compilation and faster execution. In turn, this can be used to improve the prototype under test.

When turning a concept into a product prototype, the software may need to be completely redesigned. This is especially true in situations where a development platform such as an Arduino is chosen instead of a dedicated microcontroller. The final product will almost not contain a premade development board. Arduino code (typically written in C and C++), can be partly ported to other micros, but there will be functions and commands unique to the Arduino that will need rewriting.

Hardware

Of course, it’s not just software packages that cost money; so does your time. A system that is initially prototyped with modules and prototyping dev kits (such as the Arduino platform or click boards from MikroElektronika) will almost always not be involved with the final project. Thus, a custom piece of hardware needs to be designed (this includes custom PCBs, redesigned schematics, and generating a bill of materials).

Redesigning schematics can be time-consuming, especially if the first prototype product was built using premade modules and development kits, and this will result in a heavy cost to you, the designer. The cost to you is not necessarily monetary. Rather, the time needed to make the schematic and check for errors will really start to add up. While Arduinos can be great for getting a prototype working fast, they can result in longer schematic design stages, as the designer either needs to decide if they will use a different microcontroller entirely.

Creating custom PCBs is one of the largest challenges, as it often requires years of experience, time, and arranging for manufacturing. Those who have never designed PCBs for production before will fall into many traps, including wrong hole sizes, board cut-out distances, trace widths, mislabeled components, incorrect PCB dimensions, incorrect trace widths (current handling for example), and even legal reasons.

Since prototypes are incredibly similar to the end product, they will often be built with custom circuits—and therefore built using discrete, individual components (try out our KiCad library to assist) While the advantage of dev kits and modules is that all the parts needed for them to work are integrated, they are often sold at a much higher price than their manufacturing cost.

Legal

Electronic products on the market need to pass regulations, including FCC and CE, and one regulation that is particularly difficult to solve is Electromagnetic Compatibility, or EMC. Traces on PCBs have a habit of emitting radio waves when high-speed pulses are sent down them (such as an SPI bus), and it is required by law to keep these emissions below a defined value. But it's not just EMC that needs to be considered; the product itself must be safe for consumers. Elements such as lead and cadmium must not be found in the end product (due to RoHS and REACH Standards). The product must not cause harm to the user (such as electrocution), and the product may even need to be safe for children and animals too.

Conclusion

Hidden costs can quickly pile up and add to the final cost of the project when you’re trying to determine if your project is viable as a product for the market. Even though many different areas have been touched on in this post, there are still many unknown variables that can catch you if you are not careful. So, when determining the cost of your project, you should always add a little extra on top to cover additional costs that you may have missed out on. And remember, there is one enormous cost that is nearly always overlooked: your time.

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