Ray Rogers Handcrafted Knives




Designing the Blade



To design a folding knife blade you could use a French curve, a drafting kit with protractors and compass, a calculator and a book of trig tables, or a CAD system. But, all you really need is .....


...a nickle


Yes, a nickle...or a dime, or a quarter, or a bottle cap, or any other round object that happens to be the same height as the blade you want to design. Any method you have that will allow you to draw a circle with a diameter equal to the height of your blade will work fine.


Draw your circle


Next, draw a horizontal line across the top of the nickle, and a vertical line down the back, like this:



Notice that the vertical line at the right end of the picture does not touch the nickle, give it at least 1/16th" of space. The red area is the most important part of the blade in this design method so be sure there is extra material here. Blend the end of the line into the bottom of the circle - again, it doesn't have to be perfect.

Now, add a horizontal line across the bottom of the circle and another vertical line on the front side of the circle. Let the ends of these lines extend and cross over each other, like this:



These last two lines you drew should cross each other at about 90 degrees. If you drew it freehand, like I did, and its 92 degrees or 87 degrees, or whatever, it doesn't really matter at this point so don't lose any sleep over it.

If you are going to use a blade stop bar on your knife, there will need to be a small relief cut into the blade where the bar will sit when the knife is closed. Decide what the diameter of the stop bar will be and draw a tiny circle of that diameter where the last two lines crossed, like this:



Finally, draw a line from the bottom of the circle, over the lock bar circle, and back down to the horizontal line, like this:



That's it, you have designed the critical part of a folder blade. All that remains is to add on the actual blade:



You can design the blade shape to be anything that you like:



The shape of the blade will affect the shape of the handle but that is the only effect the blade shape will have. You can make the blade as long or as short as you wish, any style that you wish. When the blade gets so long or so short that the proportions no longer look good to you, just start over with a larger or a smaller circle.

You may be wondering why there are no holes in the blade. Be patient, it all works out as you progress through the tutorial....


Next Chapter

Back To Main Page


Comments? Send me a note at:
Ray Rogers Handcrafted Knives