Making the Steel Bridge

We built my son’s 3rd grade Steel Bridge project on the CNC router. First we made drawings of the Steel Bridge from photographs. With these drawings, we cut out the pieces of the bridge on the CNC router. We cut the pieces from ¼ inch birch plywood with an 1/8 inch router bit. We glued and pin nailed the pieces together to create the bridge. The model moves like the real bridge – the lower and upper decks can move independently out of the way of boats on the river.