What Can You Expect From Physical Prototypes
Understand what are some of the main limitations when using physical prototypes to build your product.
Often there is a misconception of what a physical prototype really is, and what are its limitations compared to a final product.
Some may assume is just an earlier version of the final product but with the same level of quality. Others might see it as a duct tape mock-up of an idea. Although at times it can be more like the latter, in general, it’s something in between.
It is important to understand what you can and can’t do with a prototype or at least have an understanding of some of the limitations so you know what to expect and you don’t get ugly surprises.
First, let’s clarify what the purpose of a prototype is. In fact, the goal of a prototype can be quite broad, from testing certain features, looking at aesthetics, or just checking ergonomics or usability.
No matter the goal, the reason why we use prototypes is to get an early representation of our product idea that can be fabricated quickly and cheaper than using complex production processes.
That obviously has some implications in terms of quality and it usually determines what we can do with the prototype. These are some of the main limitations of using prototypes based on the product you are building.
Softgoods
Softs-goods prototypes are probably the simplest to build and they can be done using final materials and even equivalent production processes (such as sewing and heat bonding).
If you are designing a backpack, wallet or Ipad cover, for example, you can order the actual materials or different alternatives that you want to use for the real product and just cut & sew the patterns to create your prototype or sample.
So, you will probably get something really similar to the final product in terms of aesthetics and performance. With soft-goods, it is the craftsmanship of the sample maker that matters most.
Consumer products
On the other hand, consumer products can be trickier to prototype since most use plastic or metal parts. Those parts usually require expensive tooling and equipment to produce so usually other methods are used for prototyping.
Traditionally, the method used to prototype plastic and metal parts was CNC machining, which essentially uses a block of material (plastic or metal) and carves the desired shape on it.
The good thing is that you can use actual final materials, although the variety is quite limited. The downside is cost since CNC is usually an expensive process. Another consideration is that CNC offers very limited flexibility in terms of design so not everything can be fabricated with a CNC machine. However, this is still a good option in some cases.
Nowadays, 3D printing is a much more flexible and affordable option. The problem is that the materials (plastic or metal) available in 3D printing are different from the ones used in mass production.
Materials & construction
3D printing materials might not have the same performance or finish, especially because 3d printing produces the part in layers of material which makes the part weaker in certain orientations.
Because of the layers, parts have rough surfaces and they are usually not airtight/watertight which can be an issue for some applications.
The mechanical properties of the materials available might not be as good in terms of the durability of the parts or the resistance to extreme temperatures or to certain chemicals. New materials are being constantly developed which could change all of this in the future (likely at a cost).
Fit between parts
The fit between components might also be an issue. The precision of certain 3D printing processes is not that great, CNC does a much better job at this (with the considerations explained before).
This is one of the main issues I see in prototypes, such as parts that can’t be assembled together or being too loose. If your parts require a tight fit, consider some additional sanding process of the parts or use CNC machining.
Overall dimensions
There are limitations in terms of the overall dimensions that can be prototyped depending on the actual method used. For example, 3D printers have a maximum size constraint, which means larger parts need to be made in sections and then glued together.
Product Finish
As mentioned above, 3D printing makes parts in layers so the surface finish is usually quite rough. If you need a smooth surface or the part to be transparent, they would need to be polished.
Also, if you need the part to be decorated in a specific color or finish, it could be painted or coated as well. The problem is that the cost of applying such processes can make the prototype quite expensive in the end.
Electronic products
In the case of electronic products, the limitations are more related to scalability. Standard electronic components, such as switches, connectors, sensors, batteries, …. are not so much of a problem, those are easy to find and usually cheap.
However, you need to consider that those standard components are not that “standard”, there are many manufacturers and they might have small differences between them. So, bear in mind that what you use in your prototype might be somewhat different from what you will use in your final product.
The main electronic component in such products is usually the PCBA. You can use existing development kits such as Arduino or Raspberry-Pi (very recommendable for earlier prototypes) or produce a custom PCBA specifically for the prototype, in a very manual way.
In both cases, dimensions will certainly be much larger than a production PCBA. Also, if you need several prototypes, you will need to make each one of them individually, which increases the time to fabricate the prototype by quite a lot.
In terms of performance, prototype PCBAs can actually deliver most of the functionalities of the final product. The way they are built might not withstand continuous use and might stop functioning after a few runs. Usually enough to move into the next prototype but don’t expect them to last forever.
There Are No Limits
Knowing what some limitations are when building the initial versions of your product will help you create better prototypes and help you make informed decisions about your final product.
There is always a way to fabricate your ideas so you should know which way is more suitable for your product.
There are no limits to what we can imagine, unfortunately, there are still physical limits to what we can make. That shouldn’t stop you to use what we have today to build your ideas. Today’s technologies allow you to build amazing ideas and evaluate concepts quicker than ever. Let’s start building!
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Abilista guides innovators to develop their product ideas from concept, prototyping and all the way to manufacturing following our own step by step framework. We are already helping many entrepreneurs and startups to build their ideas by giving them access to simple and agile tools and expertise on-demand.
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