What material would be best to build a bridge lowering arm?
 

My team is in the process of designing an arm that would lower the bridge and be able to do other task such as picking up balls. We where debating wheter we would use Alluminum 8020, regular Alluminum, or cast Iron. In terms of wieght we where wondering which would the most efficient

Re: What material would be best to build a bridge lowering arm?
 

I'd consider plywood, polycarbonate sheet (Lexan), aluminum sheet, tubular aluminum, etc. 80/20 and iron would not even be on my list.

Re: What material would be best to build a bridge lowering arm?
 

Certainly a solid. Gases, liquids and plasmas would cause problems.

Cast iron? Seriously? Aside from it being far too heavy, it is not very tough: It breaks easily.

Most teams will be using aluminum. Some will use wood, or perhaps Lexan. None will use Plexiglas (Acrylic) because it is dangerous.

Re: What material would be best to build a bridge lowering arm?
 

I'd say an aluminum tube. Our bridge lowering design is simply an aluminum tube connected at each end to two arms that lower and raise the tube.