@Alex: When it comes to environmental stress cracking, there is not necessarily any advantage to making the plastic thicker or thinner. The key variables are stress and chemical exposure. If by making the plastic thicker, you can reduce the stress below the threshold, then it might be a solution. But often the threshold stress is so low that this is impractical. And if the internal stresses in the material are high enough, it doesn't matter what you do with the external stress.
Here is a good introduction to residual stress in plastics. At some risk of oversimplification, thin-wall sections are more likely to have flow-induced residual stresses, while thick-wall sections are more likely to have thermal-induced residual stresses. But either way, molded-in stresses can be significant.
I never realized the commonplace chemicals like oil and grease were precursors to stress cracking in plastics. Good to know. Also didn't realize there's some built-in prestress. It seems that, in consumer systems, the plastic always ends up cracking at some point. Is that because thin(ner) plastics are always prone to cracking (and on the other side of the design equation, making them thick enough to be more crack resistant doesn't comport with weight and cost requirements. Or are the thicker plastics just as stress-crack prone?)
The 100% solar-powered airplane Solar Impulse 2 is prepping for its upcoming flight, becoming the first plane to fly around the world without using fuel. It's able to do so because of above-average performance by all of the technologies that go into it, especially materials.
With major product releases coming from big names like Sony, Microsoft, and Samsung, and big investments by companies like Facebook, 2015 could be the year that virtual reality (VR) and augmented reality (AR) finally pop. Here's take a look back at some of the technologies that got us here (for better and worse).
Good engineering designs are those that work in the real world; bad designs are those that don’t. If we agree to set our egos aside and let the real world be our guide, we can resolve nearly any disagreement.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.