[s_forbes]

Cool stuff, thanks for uploading!

The motor reduction calculations and free body diagrams are things that I use all of the time when designing things (especially FIRST robots!), but it does seem like there are way to many teams that either don't have knowledgeable mentors or students on the subject or just don't bother doing the calculations.

They're not as hard as you would think!

The stress calculations on the other hand are a little more advanced, and I doubt that very many teams actually carry them out. I have done them for a few key components that we know will act a certain way (structural arm members and axles are good examples).

Lifetime calculations are one of those things I've never bothered to do, since there seem to be too many factors coming into play on a competition field. I generally would just make sure that key parts have a safety factor of around 3 or so, since that's about where the endurance limit is for most of the materials we use (as I recall, at least. I haven't checked up on this stuff in a while).

Is there any chance you could post the excel file that's shown in your powerpoint? I'd love to see which methods you used for all of your calculations, as they obviously have been working well for you.