Densest Building Materials

[Andy Baker]

Originally Posted by Gary Dillard

I use Andy Baker to build my drive trains. He's pretty dense

My weight is about 225 pounds. My volume is somewhere between 10,000-15,000 cubic inches (rough guess). If we assume the smallest volume of that range and divide 225/10,000 that equals 0.0225 lbs/in^3.

Considering these commonly used robot-construction materials:

• Aluminum = 0.1 lbs/in^3
• Plastic = 0.05 lbs/in^3
• Steel = 0.28 lbs/in^3

... and comparing them to my meager density of 0.0225, then I would strongly suggest not to put me on your robot.

Originally Posted by Richard

Back to FTC ballast -- I recommend U.S. Pennies. You get 100 for only a dollar. They are 0.75 inch in diameter, 0.061 inch thick, and made almost entirely of zinc. A stack of 182 is just over 11 inches long and weighs about one pound.

If you have a bigger budget, try U.S. Nickels. They are slightly larger in diameter (0.835 inch) and made mostly of copper, which is denser than zinc. Their larger diameter and density means you only need a 7 inch stack (91 coins, or $4.55 worth) to make one pound of ballast. This is 2.5 times the cost of Penny ballast, at 1.282 times the density.

Originally Posted by JesseK

I just knew that one of these days someone would suggest a feasible way to throw more money at a problem. Mo' money? Problem solved!

You may as well just pull out the big guns and use a stack of these!

Andy B.