Quote:
Originally Posted by Chak
I keep hearing on CD that 6063 is awful for FRC and just bad in every way. So why is it so common, and why does it exist at all? Is there someplace where 6063 aluminum is a good choice?
|
Every material can be bad if it's used in the wrong application - materials selection can be an incredibly complex process because you'll always need to make some sort of trade-off depending on your objectives and constraints (cost, availability, appearance, machinability, strength, recyclability, the list goes on and on). The shape and thickness have an effect on the suitability of the material for the application as well. There is no universal material that is good for every application.
As others have said,
depending on the heat treatment, 6061 is stronger and harder and may seem like the better material for almost all applications. But, if you don't need or want that kind of strength, 6061 may be overkill and 6063 may be the better option because of the lower cost.
The reason why 6063 is so readily available at hardware stores is beacause it meets the needs of most people who shop there - people looking to do home improvement projects. 6063 is widely used in home applications where appearance is key and strength may not be necessary (windowframes, some furniture applications, etc). 6061, while still useful for some home applications, is more widely used in industry for things like machine parts and structural components, and most people looking for those parts will likely be going through another vendor that is not Home Depot.
Again - this is all very, very generally speaking and the exact choices you would need to make regarding the material are entirely dependent on the application.
Another good, very similar comparison of materials often used in FRC is polycarb (Lexan) vs acrylic (Plexiglas). Acrylic is cheap, shiny, and can crack easily upon impact. Yet, it is still used as glass for hockey rinks, because when it's thick enough, it can more easily handle the impact of a puck (though not always...and then things like
this happen). Lexan is stronger and more impact-resistant, but is more expensive and scratches easily. Which would you want to use for a panel on a robot? Which would you use for a panel that's part of a pit display or a trophy?