The route from line drawings on the lofting floor to actual parts is not always a simple one. Take the case of Cherokee's stem.
We're making the stem and fore keel as a single part made up of bent laminations. We'll steam the layers of wood, and bend them over a bending jig to get them into the proper shape. Once the wood has cooled and settled into its new bent shape, we'll glue the layers together in a sandwich, using the same jig to makes sure that the proper shape is retained.
So, the task at hand is to take the shape of the stem and fore keel that we've drawn on the lofting, and build the bending jig that will make that shape.
Here's the shape we're starting with. The batten on the right traces the top surface of the keel.
 You can see the lower edge of the keel drawn in ink on the lofting floor to the right of it. The trick now is to transfer this shape to pattern stock (i.e., thin plywood) that we can use to transfer the shape to the jig that we're building. If the lofting floor was very solid (say, made of 3/4" plywood), we could lay nails down on the floor with their heads aligned along the lines we're trying to copy, like this: This is the stem from a Whitehall pulling boat lofting that we made last year at IYRS. The nail heads are sharp along their sides, and you can tap them into the lofting along the lines that you want to copy. Now, to copy the pattern, lay some good plywood on top of the nails and press it down firmly. When you pick up your plywood, you'll have a series of little dashes pressed into it where the sides of the nail heads were. Voila! Trace those dashes and you've now transferred your lofting shape to a piece of plywood that you can now cut out and use as a pattern.
We didn't do that though, because our plywood lofting floor is too thin. It would just flex if we put another piece of plywood on it and pressed down. No fear, though, there's lots of ways to transfer a pattern.
In our case, we made up some wood fingers.
 These get screwed to the lofting floor so that the end of the finger just rests against the batten we want to copy. The batten is defining the shape of the upper surface of the keel. (by the way, you don't have to have a batten. You can copy a drawn line with this method too. Just put a little block of wood right on the line you want to copy and touch that with the finger) Notice the little gap under the finger? That's so you can slide a thin sheet of plywood under the finger. Now look, you can put a batten back along the ends of your fingers and trace your exact shape right on this new strip of plywood. Voila! You've got pattern stock! Cut along the line you just made and you've successfully copied a line from the lofting floor to a plywood pattern. You may have noticed that this is a very long pattern, about 16' in fact. We have to use two 8' sections of plywood to make it up. We hot glue a patch in the middle to hold the 2 lengths together. Next we take this pattern and lay it on top of 2 2x12's joined together to fit the curve of the pattern. There's the pattern on the left and the lumber on the right. The 2 sections of 2x12 are held together at the proper angle with that patch of blue plywood in the middle. We trace the shape from the pattern to the lumber next.Now we cut the lumber close to the line and clean it up with a plane to make sure the curve we've got is smooth. Glue up another 2 lengths of 2x12 just like the first one. clamp them together, and trace out the pattern of the first 2x12 onto the 2nd one. Take them apart, and cut close to the line you just made with a jig saw. Now screw them together so that the rough cut 2x12 sticks out just a little bit from the finished 2x12. Using a router with a straight bit and a guide bearing, you can now cut an exact copy of the curve of the first 2x12 into the 2nd one. Now you have 2 sturdy boards that are exactly the same shape and that accurately match the shape of the upper face of the keel. Almost there. Soon all will be clear.Now, while the 2x12's are still screwed together, cut out a series of notches along the top surface. This guarantees that the notches are exactly lined up on each 2x12. Now you can unscrew the 2x12's from each other.Here's why: Using a series of 2x4's cut to the same length, and cut to fit the notches you just made, you now create a curved clamping surface that mirrors the line you drew a while back on the lofting. These 2x4's are glued and screwed into the notches (there are some others also attached along the underside of the jig to stiffen it), and they make for a very solid jig. Now, we can finally steam bend some wana (the wood we're using for the stem and keel), and clamp it down to this jig to form it in the shape of the stem and fore keel.Whew. It's not a quick path from drawing to part, but you really don't want to mess around with the shape of your stem and keel now, do you?Meanwhile, the lofting continues. Here are a few of the diagonals going down. Now if those aren't fair lines, I don't know what a fair line is. We're getting very close to being done with the lofting. All the work Karl and Robin have been doing will pay off in the future as we'll be referring to these lines constantly as we're working out various bevels and part shapes.
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