Today, the 5th and 6th grades students made their sieves for diamond mining and this afternoon 7th and 8th grade students and 11th and 12th grade students team up to do special projects illustrating energy and mechanics. One group is making a windmill, another is attempting to make a model catamaran, and the third is making a model of one of Leonardo DaVinci's illustrations of a siege engine. I expect it to be fun.

As you can see in the photo above, the sieve is a simple thing. Cut the wood parts to length, sand them and nail them together. Then cut window screen and staple it in place on one side. To give strength to the window screen, an additional layer of 1/2" mesh hardware cloth is added.