Dose anyone know why vex change the steel parts to aluminum?
Vex didn’t replace steel with aluminum: you can buy both.
This gives you multiple options for robot material. They both have pros and cons.
VEX still sells both, but the starter kits changed from using steel to using aluminum.
VEX probably switched to aluminum in the kits because most teams prefer aluminum for most uses.
Steel is cheaper than aluminum (which is probably why VEX used it in the kits before), but it’s worth it to spend a little extra to get the aluminum.
Most teams only use steel when they need steel (such as when they want part of the robot to be heavy), or when they don’t have enough aluminum.
For the record, all the new V5 kits have been separated to be either “Classroom” or “Competition”. Classroom kits still use Steel, and contain a few more sensors, while Competition Kits contain Aluminum, and more High Strength Gears, Sprockets, etc.
Dude you should get a philosopher stone highly recommend!