By Horst Fiedler
I rented a plate compactor from Home Depot that uses the Honda GX160 gasoline engine. As part of the instructional demonstration they said to move the engine’s fuel valve lever to the position marked “ON” so gas could get from the fuel tank to the carburetor. After getting it home I started using it, and after a few seconds the engine quit. Nothing would get it to restart.
Getting on my hands and knees I soon spotted the problem. The fuel valve markings were obviously designed by monkeys.
There is a decal to the left of the choke and the fuel lever. The choke label is fairly clear since it lines up with the gray choke lever. The gas pump obviously has to do with fuel, but it is not aligned with the fuel lever and there is also a stud and bolt in the way.
The black fuel lever is hard to see against the black plastic cover. They should have made it red or yellow. The worst part is that if you don’t see the arrow pointing to the right, you assume “ON” is where the lever should be positioned. The “ON” position is actually OFF and you have to move the lever away from the ON marking. The actual ON position is unmarked.
It worked for the in-store demonstration because there is enough gas in the carburetor to run the engine for about a minute.
When designing a product, controls should be in a color that contrasts with the background. Selector levers should have both positions clearly marked, also in a contrasting color. Lastly, the control labels should be visible from the normal operating position.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.