[sanddrag]

We replaced a 3/16 solid plate with 1/8 lasercut and sides bent down and it is 2 lbs lighter. It is still just as strong. We replaced another 3/16 solid plate with a 1/8 solid plate with sides bent down and saved 1.25 lbs there. We replaced the 1/2" di steel hook with a 3/8" di steel hook and saved about 2 lbs there. We replaced the .125 sheet metal pivoting arm with one made from .063 and there is only one place where it flexes where we just added a little .063 thick brace. Saved abotu 2 lbs on that. We chopped down our window motor/arm mounts and cut the $^#% out of the 3/16 mounting plates and saved about another 2 lbs there. We removed the van door motor mount completely and lightened the U-pillow block and saved about .5 lb there.

We also lightened everything we could from the start (axles, gears, sprockets, shaft collars) Without the hanger, our robot is basically the same as last year's, except about 35 lbs lighter. I'd say we did a good job with lightening. You will see strategically placed cutouts and bends and a well chosen material thickness, not a whole bunch of speed holes.

A lot of times in FIRST the strength of a component is largely underestimated and the forces applied to that component are largely underestimated. Sure it is cool to have a robot built like a tank but when it is 130lbs and all it does is drive, that is not cool.

You don't always need thick material to get the job done. Throw in a couple bends and it makes it a lot stronger.

Our battery/compressor tray is only .040 thick but it doesn't flex because it has bends.

Over the off-season, each team should really assess the strength of each component and try re-making it out of a thinner material or with more cutouts.