If plotting out points for new templates, what do you find gives the best natural curve to bend around and meet those points? I used to use a piece of quarter round and later switched to a 10’ piece of aluminum from Home Depot. But I’ve heard of Brewer using the same thing all the time for his curves and having so many people call them “magic” curves. I’ve heard of people using a fishing pole blank to bend the curve, etc. I was recently told by a person that if you use the rule of thirds on the board (6’ board would get 9’ of curve from nose to tail) that it doesn’t matter where your wide point or nose and tail widths are… that it will work like a magic board. I like to make my own curves, but I have also enjoyed shaping boards from classic lines templated off of other boards. The question in my mind these days is, how did so and so come up with the method or idea for this curve or that curve? What was the purpose? Why did so and so think this? what did they use, and is there a right or correct way that works best??? So many thoughts… sorry for rambling…
When using battens how are you holding them in place to then run the pencil mark? I’ve tried holding battens with with both hands, both feet, holding pencil in teeth, hasn’t worked so good. I’ve read the boatbuilding folks tack down the battens, tried that, didn’t work so good either. Boatbuiding paper drafts are made with battens held in place with lead weights.
i use a strip of thin fiberglass(like a window shape strip) but i hold them in place with the long pins used in high school bio labs to hold the poor critters for dissection, they are about three inch long and have a T top . i got the idea from a book on designing sail boats back in the 1800’s
When using battens how are you holding them in place to then run the pencil mark? I’ve tried holding battens with with both hands, both feet, holding pencil in teeth, hasn’t worked so good. I’ve read the boatbuilding folks tack down the battens, tried that, didn’t work so good either. Boatbuiding paper drafts are made with battens held in place with lead weights.
It depends on the material I’m templating on; tiny nails work on masonite while pushpins are better on foam.
These are ‘‘stops’’ to either side of the batten, not through the batten itself. I’ve also done my share of holding
with both hands and feet (lol). Sometimes an extra pair of hands, if available, can be really helpful.
Good on you guys for learning to fair your own curves.
Basically, you are asking about splines. Sure… computers can be used to make splines, but that is not how they used to do it. Here is a snippet from a Wikipedia article about splines.
[indent]…Robin Forrest describes “lofting”, a technique used in the British aircraft industry during World War II to construct templates for airplanes by passing thin wooden strips (called “splines”) through points laid out on the floor of a large design loft, a technique borrowed from ship-hull design. For years the practice of ship design had employed models to design in the small. The successful design was then plotted on graph paper and the key points of the plot were re-plotted on larger graph paper to full size. The thin wooden strips provided an interpolation of the key points into smooth curves. The strips would be held in place at discrete points (called “ducks” by Forrest; Schoenberg used “dogs” or “rats”) and between these points would assume shapes of minimum strain energy. According to Forrest, one possible impetus for a mathematical model for this process was the potential loss of the critical design components for an entire aircraft should the loft be hit by an enemy bomb. This gave rise to “conic lofting”, which used conic sections to model the position of the curve between the ducks. Conic lofting was replaced by what we would call splines in the early 1960s based on work by J. C. Ferguson at Boeing and (somewhat later) by M.A. Sabin at British Aircraft Corporation.
The word “spline” was originally an East Anglian dialect word.[/indent] You can make your own spline curve by placing some long nails along a flat surface, and then weaving a long strip of wood between them. You will get a pretty boring looking shape if you only use three nails: one for the front, one for the back, and one for the widest point. As Kensurf suggested above… try adding a nail at 12 in. off the nose, and another at 12 in. off the tail.