Its well established on this insane thread that air is not going to make that much of a difference. However, I will offer up some tips from my experiences at competition on saving weight:
- go check your weight out at the inspection station as early as possible. The scales used at competition are of much higher caliber than what the average team has back at their shop, they are also calibrated specifically for the competition.
- Check your robot for bolts that aren't used, dust that has accumulated, random screwdrivers just sitting on it. You'll be surprised how many tools the field crew picks up over the course of 1 event. Most of that weighs more than air.
- My favorite weight reducer this year is high density foam, you can get it in 1" sheets and its mostly air. And does a much lighter job where people tend to use Lexan/Polycarb type materials. You can also find it easily a lot of places (just look up)
- After you do all of that, then try swaping out thinner pieces of metal/polycarb, you'll save more weight there than other places
- Now you can proceed to the art of swiss cheesing.
*results may vary