The strength of the carbon-fiber frames is literally woven in before they are molded, as Nate is doing here. A sheet of thin cured unidirectional carbon fiber is cut into strips which are then stacked and interwoven in the mold to provide adequate strength to junction points and corners. After the fiber strips layup, the mold cavity is filled with black epoxy and left to cure overnight. The large surface area of the mold requires that the mold lid be held down in the middle of the mold in addition to the outer perimeter. Threaded ¼-20 wing-nuts are used to hold the lid down rather than an array of clamps around the edge. Clamps are used to secure the near long side of the mold, which serves as a separate “action” required by the presence of undercut features along the inner face of the frame.

When the mold is opened the next day, this side, which is hinged, is opened first, which frees up the frame to be lifted vertically out of the mold.