Thank you all for the feedback and encouragement!
Feedback Incorporated
I've added VexPro as a supplier and changed the research page to say, "#25 chain is very common in FRC applications, and roughly the same strength as 15mm belt but only half as wide." Originally I used the rated working loads for OEM chain suppliers (up to 154 lbs) instead of the McMaster-Carr chain (88 lbs) teams are more likely to buy.
Robot Speed
The design supports a variety of speeds if you swap out the Stage 2 sprockets. The current sprockets (34/22 = 1.55:1) give 12.6 ft/s, but you could easily go as high as (42/16 =) 2.625:1 for 21.4 ft/s, or as low as (32/22 =) 1.45:1 for 11.9 ft/s. We could also make tank mode faster (but at the expense of pushing force, obviously).
The main reason I lean towards 10-13 ft/s is that my team got burned in Aerial Assist by a 22 ft/s robot with HORRIBLE acceleration. Now I completely agree with the statement "The true measure of speed is the time it takes to go from A to B including acceleration". For reference, I've calculated that a 10 ft/s robot is actually FASTER than a 16 ft/s robot for distances less than 10 ft. Every distance has a different sweet spot for gearing.
Level of Documentation Detail
While documenting our work is important, it obviously takes a lot longer: I think it's taken me about 3X longer - starting from scratch - than it would have taken with bare-bones documentation. So creating tutorials like this is probably more appropriate during pre-season than the 45-day build season.
The counter-argument to that - which I'm VERY excited about - is the Wikipedia model: no one sits down (by themselves) and writes a high-quality Wikipedia article from scratch - it's a collaborative effort that benefits from a lot of eyeballs, and each of the 100-odd edits takes far less time than building an article from scratch.
I can definitely see a team refining a tutorial like this (or adapting it to a different robot module) during the build season.
Thanks again and I look forward to working with you guys! Please email me at
alecmuller@gmail.com if you'd like edit access to this tutorial.