Now it was time to build the counterweight. This is the container that holds the heavy weights that cause the arm to swing. The counterweight was built from complex curved parts that interlock to form a very strong framework. Inside the framework are rocks, sand, and lead shot. I can put up to about 500 pounds of ballast in it, although that is a lot to handle. So, I only keep about 300 pounds in it. The counterweight swings from a pivot.

Because the counterweight looked like a portion of a wheel, we decided to use wheelwrights' terms to describe the parts.The straight pieces radiating out from the central hub are called SPOKES. The curved pieces forming the outer radial surface are called FELLOES. It all revolves around a HUB.

This is the frame of the counterweight. Sometimes it is called "the counterpoise," "ballast," or simply "the weight." In any case, it must be sturdy to hold the rocks and lead.