Taylor Made: Feats and Fails of Engineering, Vol. 2
I’d like to start this off by discussing continuity in projects. Although generally not vital for the success of the design, continuity is nonetheless an important consideration in engineering. A simple example of this is using the same type of screws on a given part. I was recently looking at an RC Seamaster (an example Seamaster is shown) and I noticed that the screws holding the motor on the motor mount had varying heads. This meant that removing the motor required multiple types of screwdrivers.
In similar fashion, the cross bolt for an aftermarket rear motor mount I helped put on a Ford Focus ST needed a special sized Allen wrench instead of the typical socket. These observations struck me as good reminders that we need to consider and plan for efficient assembly in design, and continuity is a part of those considerations.
It is also important to actually test your design. The drill pictured has a lip at the bottom of the handle, presumably so that it can stand up on its own when you set it down. However, despite having this lip, the drill is still nose-heavy and will tip forward when set down, i.e. it CAN’T stand on its own like most other drills. The presence or lack of a drill bit does not change this flaw. A simple extension of the lip would have fixed this.
On the other side of the design spectrum, the RC boat shown has two gas motors on the back. A close look shows that they are actually airplane motors—each one has a spinner at the top, which can be manually cranked to start the motor.
On an airplane, the motor would produce thrust by driving a propeller located at the spinner. However, for the boat these have been converted so that power is directed to the marine propeller shafts instead of the spinners.
Switching to full-scale, take a look at the 1960s throttle mechanism from a straight six carbureted engine on a deep V speedboat. Instead of fuel being injected directly, it is mixed with air in the carburetor and then fed to the cylinders. The throttle mechanism shown is attached to the carburetor and is one of two valves that control how much fuel is added, with the other being the choke (handy for cold starts). This method, although dated, can still have great performance with proper maintenance.