pic: Prototype Drivetrain

[JamesCH95]

Originally Posted by AdamHeard

If a designer knows and understands the limits of a welded 6061 frame, this is not a downside. We've been running welded 6061 frames for years, and the one broken weld we had was just horrible, awful, horrible design. Please stop saying how awful welded 6061 is every chance you get. There are a lot of advantages to teams only having to stock primarily one type of aluminum (we still stock a lot fo 2024, 7068 and 7075 for shafts however).

Clearly welded 6061 can be used with great results, many teams (like yours) have. I am merely suggesting that there could be a more optimal design. There are very few deviations from bolted aluminum chassis, welded aluminum chassis, and folded sheet aluminum chassis. I am just trying to encourage students and mentors to re-evaluate how they make their robots. Of course there are other factors like material cost and availability, and those do matter.

I have a suspicion that many teams just "make the chassis like we always do" without ever trying to optimize it or even try something different (if only on paper as a theoretical exercise). A CAD model is great for that, the model could made with different configurations: one with aluminum tubing, one with steel tubing. Pick a few load cases that you know the aluminum one will pass, then optimize the steel one until you have the same factor of safety and see what the weights are. It'd be a reasonably in-depth undertaking, but excellent practice for anyone who wanted to do it. I know SolidWorks has multi-configuration support, and some of the simulation packages even have built-in optimization function that are very easy to use. In the past SolidWorks has donated free copies to FIRST teams.