Alternative Materials

[Cyberphil]

Well this year, we started with aluminum arms. In Trenton, all 3 sets we made got completely destroyed. We needed an alternative, and we thought titanium. So we made titanium ones that worked 10 times better.

[dtengineering]

And, I meant to add, if you are looking for inspriation for what can be done with wood (above and beyond the Mosquito, that is) check out http://www.joeharmondesign.com/ for a wooden car.

Not just any car... a 300mph exotic... that almost fits the new "no metal" rule. Wooden springs, spokes, supension... wow!

Jason

[vivek16]

lexan/polycarbonate

You can get the stuff in this green house building stuff. It's ribbed and is incredibly light. 525 will attest to this, they used it on their arm last year. Crazy stuff.

-Vivek

[FourPenguins]

One of my favorite materials of all time for small parts is Acetal resin (Delrin). It is a good bushing/spacer material and some teams have even used it for gearbox plates.
Polycarbonate has reached the point of almost being mainstream, so I won't go into detail. However, keep in mind that it comes in tubing as well as sheets.
One of MORT's cooler innovations has been polyurethane foam. It's a two-part mixture (like an epoxy) that expands to fill whatever you pour it into. It's good for adding rigidity to tubes.
Also available is solid polyurethane, which can be used to cast parts. For example, if you have a small, low stress part, machine one out of aluminum, and then make a mold from it and cast the rest.
Aluminum is not nearly as one-dimensional as one may think. Different alloys have different properties and a little research will go a long way. Look into the 7075 and 7068 alloys for high strength options.

[R.C.]

Originally Posted by FourPenguins

Look into the 7075 and 7068 alloys for high strength options.

My favorite, better if it is donated.