1. On the high-quality core board (joinery board), dig out the skeleton according to the radian, stick two layers of three plywood on both sides of the core board, and then glue. When applying white latex, it must be uniform to ensure that the three splints are tightly bonded without leaving gaps.
2. Make a model with a large core board (joinery board) according to the radian, and fix the second and third layers of plywood on the model. Saw the high-quality twelve plywood into strips with a width of 20mm, nail them on the measured three plywood at a distance of 30mm, fix them on the large core board model, and nail another layer of three plywood.