Children have a way of simplifying everything, whereas adults tend to do the opposite. Sometimes making things complicated is unavoidable, but more often than not we should view things from a child’s perspective and keep it simple. Adults even have an acronym for this: KISS, or Keep It Simple, Stupid.
Keeping it simple is the most important advice anyone can give you about mechanism design. Even mechanisms that require a lot of movement to achieve their desired results will work better if you find the simplest solution.
There are always multiple ways to solve a problem, of course, and sometimes the simple solution isn’t the most obvious solution. It can take time and effort to simplify things, but if you take the time and make the effort, you’ll end up with a better mechanism design.
At Creative Mechanisms, we consider any product with a moving part to be a mechanism. Even if the product has only a single piece flip-top lid with only a single living hinge, it’s still a mechanism. This product, although it is molded from one piece of plastic, is considered a mechanism because the lid moves; that is, opens and closes. And while it seems like it would be awfully easy to keep such a small project simple, you’d be surprised at how much engineering detail goes into that simple, one piece mechanism.
We have also made other products in which the goal of the mechanism was to get as many individual motions as possible out of a single motor. Projects like this require many moving parts, which makes it extremely easy to fall into the trap of over complication.
In engineering and mechanism design/creation, there are manufacturing and assembly tolerances for each part.
That is, every part you add to a product increases cost. Every part you add to a product increases assembly time. Every part you add to a product increases the chance of errors. Every part you add to a product increases the opportunity for problems throughout the life of the product. The more parts you start with, and the more parts you continue to add, the more chances there are for problems – problems during the development of the mechanism, problems during the manufacturing of the mechanism, and problems during the mechanism’s life with the consumer.
So the goal is always to make something with as few parts as possible. In fact, it requires more skill to create mechanisms with fewer parts and the most elegant mechanisms are those that achieve very complicated motions with just a few well-designed parts.
It doesn’t matter whether it’s a simple mechanism with only a single piece or a complex mechanism with 100 or more pieces – remember to KISS, or Keep It Simple, Stupid. Working toward finding the most elegant solution while not increasing your parts count will pay big dividends throughout the life of your product.