The frames attach to the floors and provide structural support to the planks that will make up the hull of the dinghy. The frames are cut out of a larger piece of Douglas Fir with straight grain and quarter sawn annual growth rings. Care was taken to avoid any large knots in the wood while using the wood in the most efficient method possible.
The frames will guide the planks in flaring the top sides. The chine is located two full inches inboard of the sheer, and the frames need to embody this flare. To accomplish this task, careful measurements were made on a piece of lofting paper, where the final shape of the frames could be determined.
The top of the frames are 18 inches above the bottom of the floors, and extend 2 inches beyond the floors in an atwarthship dimension. Knowing that the floors are around 5 inches high, the frames only need to extend 13 inches upward. Some overlap was added to allow firm attachment between the frames and the floors.
15 inches of vertical height is decided to be the appropriate length for the frames. The next variable is the flare, 2 inches atwarthship. By using squares, I was able to plot the points that the frames needed to reach. Then it was simply a matter of connecting the dots.
The base of the frame shall be 1.5 inches and taper down to 0.75 inches. The bottom of the frame is set horizontally, serving as the reference point. The top outboard side is measured 15 inches up and 2 inches out. The upper inboard point is meaured 0.75 inches in from there. With the lines drawn to connect the dots, I had a diagram of the frames, now to bring them into real life!
The drawing was then cut out and laid on an appropriate board. Marking the corners and connecting the marks outlined the frames, ensuring that no knots are included and as little wood is wasted.
The frames were cut out on the bandsaw, converting the cluster of drawings into real life sticks that would become the frames of our dinghy.