Add to Wishlist Add to cart Quick view Add to Compare Simple Machines Block & Tackle $24.99 One pulley can be used to change the direction of the force applied by a cord several pulleys can be used to make this simple...
Add to Wishlist Add to cart Quick view Add to Compare Simple Machines Gear Train $39.99 This device illustrates the workings of a system of gears. When you turn one gear, the meshed teeth cause the other gears to ...
