Carving a one-piece wooden folding knife

[pallin]

Some forum members have expressed interest in how to carve a wooden folding knife from one piece of wood. This is in the category of whimsies because the knife is a novelty but unusable for cutting. Below are some photos of what we're talking about. The first photo shows an example of two bladed knives. The one we'll attempt in this tutorial will be the larger knife with a single blade as shown in the 2nd & 3rd photos: The material is basswood, 3/4" x 1" x 8" - the handle part is 4-1/2" long with the blade pivot 1/2" from the end. You can adapt the shape to your favorite folding knife.
In the 3rd photo, the dotted lines show the area in the body of the handle that will be removed to make space for the folded blade.
In the sample knives the pivots were 1/8" hardwood dowels. But in this tutorial project we're going to be purists and make the pivot from the one piece of wood. This means the grain of the pivot runs crossways to the forces on the blade, so it's a little delicate. We'll make it larger than 1/8".

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[pallin]

First we cut the outer shape. You can do this on a bandsaw or with a knife. As I said in the first post, the handle portion is 4-1/2" long and the ends half circles. You don't have to shape the blade at this stage, but it may help to keep from confusing the handle from the blade end.
Next we'll begin the shape the blade. I've divided the 3/4" thickness into three equal parts. We'll carve the blade down to just the middle 1/4". Of course it would be easier to saw down both sides of the blade, but we're being "purists" on this carving project. You will note that most of the carving is being done with gouges. In the first photo I have marked the edge to show the portions (crosshatched) that will be removed.

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[pallin]

Here we're continuing to shape the blade, cutting 1/4" off both sides of the wood. I'm using a #5-12mm gouge for both the stop cuts and the wood removal. The surface of the blade (at 1/4") is where we'll make the knife cuts to release the pivot pin, but that comes much later. The photos below are of the blade shaping.
Next, we'll put the knife in a vise and use a #7-6mm gouge to carve the slot in the handle.

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[pallin]

This might be a good time to take a close look at your real pocket knife. Open and close the blades. There is a step along the back side of the blade that forms a stop when the blade is opened. The base of the blade around the pivot pin is somewhat rounded, but has flat spots to hold the blade in the fully open or closed positions. The bottom of the knife has spring bars to put pressure on the flats. To replicate the spring bars in our wooden knife is difficult, so we'll just put some friction in the blade rotation.
I did some experimenting with the size of the pivot. I will be cutting the pivot with gouges. The #9 gouges make a full circle with two cuts. The #8 gouges make 1/3 of a circle with each cut. Using the #9-3mm or the #8-3mm makes a pivot that's about 1/8" in diameter, but that's too weak in basswood. So I'll probably use a 7mm wide gouge, which will make the pivot 5/16" in diameter. As you'll see later, we need to plunge the gouges 1/4" into each side of the handle at the pivot point. (It would be so much easier and stronger to use a 1/8" dowel!)

[mtngoat]

Nice work, looks good. I have been wanting to try one of these for a while, now I am motivated.

[pallin]

Next we want to precisely locate the center points for the pivot pin on both sides of the knife. Using a mechanic's square, mark the center points 1/2" from the end of the knife handle (blade end), and 3/8" from the bottom edge. Try to make them exactly in line with each other - the dimensions are not critical. See photos 1 & 2 below. Photo 2 shows the line for the blade stop.
Using the center points for alignment, lightly press the gouge you will use for cutting the pivot pin. The one I'm using is #8-7mm. See photo 3. We will not actually shape the pivot until after we've hollowed out the handle. In the process of cutting the pivot, we will plunge the gouge in about 1/4" on both sides. Then we will use a thin knife to cut parallel to the blade just deep enough to meet the sides of the pivot. See photo 4.

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[pallin]

Now we're going to remove the wood from the slot in the knife where the blade will fold in. I'm using a #7-6mm gouge. First, outline the slot with a knife cut. Then cut the middle out, maybe 1/8" at a time. Make a stop cut to limit the wood removal at the base of the blade. Check the depth often to make sure you don't go through the bottom - leave only about 1/8" at the point where the bottom touches the blade step.

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[pallin]

After carving the complete blade slot in the knife, we can begin to release the blade. Work very cautiously on this phase! The pivot is cross-grain and easily broken.
First cut the round plunge cuts on both side that outline the pivot pin. They must go in to the surface of the blade. I have cut this with a #8-7mm gouge. Perhaps it could be done with a very pointed knife - thinner the better.

Next, cut along the surface of the blade toward the pivot, try to just reach the plunge cuts from the sides.

Extend the gouge cuts along the bottom of the slot until they reach the step in the back edge of the blade. Proceed with each of these steps until the blade can be moved slightly. Do not try to close the blade until you've carefully shaped the curve at the base of the blade - (coming soon).

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[pallin]

As you work the blade free, don't force it! If it begins to bind against the back of the handle, shave a little more off the base of the blade and/or the bottom of the handle slot.
Now, I must admit this was a difficult part for me also. Even with 5/16" pivots the pins broke off. So I glued them back with crazy glue - not easy because the blade has to be in place when you glue the pins back on. Any oozing glue will lock the blade in place again. Also, the carved pins have a lot of "slop," so the blade moves around more than you would like. As I said at the beginning, an 1/8" dowel pin is much easier and stronger.

[pallin]

Once you are satisfied with the blade movement, it's time to put the finishing touches on the knife. Shave the blade to its approximate bevel (photo 1). Cut lines to separate the metal ends of the handle from the gripping part. Texture the body of the handle with shallow gouge cuts in a random pattern (photos 2 & 3). Sand lightly, if desired, and apply finish. I usually prefer leave the wood natural or with a clear finish so that viewers recognize immediately that it's WOOD.

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