Quote:
Originally Posted by nuclearnerd
Yeah, I'm still *really* surprised at the things FRC people use 7075 for. It's aluminum trying to be steel - same strength as (mild) steel, but way less stiffness, way less toughness and way less hardness. (The latter can sorta be overcome with hard anodizing, as long as you don't actually stress the coating too much.)
7075 could maybe find use in highly stressed structural plates, where you want to save weight on a big piece. But for small shafts & gears, don't be silly - just use steel!
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Isn't that almost the goal of 7075 for most teams? We want something kinda like steel but at 1/3 the weight? Since its engineering there is going to be a tradeoff...
It just doens't make sense to use steel on most of the robots, teams would almost NEVER make weight.
Common examples and weight differences:
3 Foot piece of Hex: AL .79 lbs steel would be closer to 2.37 lbs!
84T @ 1/2" Hex: AL: .53 lbs steel would be closer to 1.5 lbs!
In FRC using steel over aluminum in a many applications just doesn't make sense, especially not to our team and a whole lot of others. Also the run time is so short on the FRC robots that we really don't see failure.