I don't know why it is, but as soon as I finish one knife, I simply can't wait to get started on the next. Since I just finished up the "Pride" knife build, it's time to start another. I decided to do something familiar, something with front and rear bolsters like I usually build, just to bring myself back to center. I chose a new design that I call "Panther" for this build that I think will look really handsome. It's similar to my "Cougar" design with a few aesthetic alterations. I thought with this build I would focus a little more on how I go about doing some of the small tasks that a knife build requires.
I have had many people over the last few years that I have been making knives ask me where I get the blades and other parts for my knives. When I tell them that I make everything from raw materials, i.e. bars of steel and chunks of scale material, they look at me like I have lobsters crawling out of my ears. They find it hard to believe that something so nice can be made completely by hand. Well, if you find yourself sharing sentiments with these skeptics, follow along with this build and you will see what I mean about my knives being "handmade".
The above photo shows the raw materials that will eventually become a working, functioning piece of art. The green paper pattern is a CAD drawing of what the final product will look like that I like to keep close by for reference during the build. Below the pattern you will see laid out a nice piece of maroon-colored Micarta that I will be using for the scales on this piece. To the right is a piece of 416 stainless steel that the bolsters will be cut from. Below that is a piece of CPM 154 that will be used for the blade, a thicker piece of 416 stainless that the spacer will be cut from, and at the bottom, a large sheet of 6AL4V titanium for the liners.
This photo shows all of the metal parts after they have been rough cut on the band saw. Nothing special or tricky here, I just cut outside the lines. The rest of the waste will be taken care of on the grinder.
As I just mentioned above, I do the final shaping on the belt grinder with the flat platen attachment. I still haven't gotten around to making a larger work rest, but this small one works fine for the time being. I use an 80 grit belt and take the shape down to the line.
Here are all of the parts after their initial shaping. I leave the bolsters a little large until they are properly fit to the scales. I'll show that process further on in this post.
At this point, I glue the patterns onto the pieces with good, old rubber cement, the kind you used to use in grade school. I also superglue the liners together as well as the bolsters so that they can be shaped together on the grinder. The patterns are also there to help locate the holes that will need to be drilled.
Here's a little side note. I got tired of chasing drill bits around the shop, trying to remember which size I needed for which task and which drawer or box I put that particular bit in. I took a scrap block of wood and organized all my usual bits, reamers, and countersinks and labeled what each is used for. Now, when I'm drilling a hole for a particular purpose, I just have to read the label and pull out the right bit for the job. I'm glad I took the time to make this little stand as it really helps to keep me organized.
After grinding all the parts down to their final shape, I begin the drilling process. I use a 1-2-3 block on the drill press for this process. It elevates the work off the table enough to give clearance for clamps and keeps everything square. All holes at this initial stage get spot drilled with a #56 bit to start with and drilled again with larger bits where the holes need to be bigger. I also use a drop of 3-in-1 oil for each hole to extend the life of my bits.
Here is the stack of liners after all the holes are spotted. Since this is a prototype, I have three liners in the stack. The third liner will become the future pattern. As holes are drilled through the liners, the super glue joint tends to split apart because that last burr on titanium bends instead of being cut off. That's why you see the three pins holding things together in the photo above. Everything needs to stay aligned or the holes from one side to the other will not line up right.
The screws that pass through the liners and spacer are hidden and have to be countersunk so the heads are concealed below the scales and bolsters. I use a standard countersink bit to cut these holes. The hardest part is figuring out which holes get countersunk. I mark each one with an "X" so that I don't get confused.
Here is the little jig that I use to set up the proper depth of countersink for the screw heads. It's simply a small piece of titanium scrap that has a countersink hole already cut in at the proper depth. I lower the drill press down until the countersink bottoms out in the hole and set the depth stop on the drill press. With everything set up, it's just the simple matter of spinning out the holes.
Here's a pic of the liner with the countersink holes cut in.
I like my pivots to be as precise as possible, so I use a 1/8" reamer to make the final hole through the liner where the 1/8" pivot will pass through.
I also like to countersink the backside of the blade where the thumb stud screw will go. This drops the head down below the blade surface to get it out of the way. I use a standard drill bit just a fraction larger than the screw head for this step. I also ream the pivot hole in the tang to 1/8". This hole will be enlarged to accept a 3/16" bushing later on, but for getting things aligned and shaped, I keep the hole at 1/8".
Here are the tools for tapping the threads into the liners. I tap all my threads by hand and always use a tapping lubricant. I broke a lot of taps in the beginning, but I've found that using this lubricant really helps. Also, knowing when to back the tap out as it binds, is essential and came from the experience of breaking a lot of taps! Yes, there are better ways to do this, but this works for me.
Because I needed both hands, I didn't get any photos of drilling the screw holes in the bolsters. To explain, I simply clamp the bolsters in position on the liners and drill them with a #56 bit. In the picture, I have the two bolsters pinned together with #56 pins. The purpose of this is to get the surface that will mate with the scales even. There is nothing worse than to have the bolsters a little off on the finished knife. Pinning and grinding them together ensures that both surfaces are exactly the same.
Here is a pic after the bolsters have been ground. Notice that the surfaces facing up are in exactly the same plane. Just what we are after. At this point, the screw hole alignment and the scale mating surface are the only things that matter. Everything else will be shaped once the handle is assembled.
Next, the surfaces of the bolsters that were just trued up get dovetailed. To do this, the inside surface gets ground at 30 degrees on the disk grinder just enough until grind reaches the other side. I've played around with different angles for dovetails, but find that 30 degrees best suits me.
After getting their dovetails ground in, the bolsters go back to the drill press. I don't have any photos of this step, but the holes get enlarged for the screw to pass through and a countersink is added for each screw head. I also cut out the Micarta scales on the band saw and grind the mating surfaces at the same 30 degrees as the bolster to complete the dovetail. The above photo shows the fit.
Again, I missed a few photos, but the scales get drilled and countersunk just like the bolsters. To do this, I fit the scales up tight against the bolsters and clamp them tight before drilling. This ensures a nice, tight fit. I keep using the word tight, but tight is exactly what I want. No daylight should be seen at the joint. The scales also get pinned together and the back end which will mate up with the rear bolsters get trued up as did the front bolsters and ground at 30 degrees to prepare for fitting the rear bolsters.
This picture shows the handles after the rear bolsters have been fitted, dovetailed, and screwed in place. This is done in the same manner as the front bolsters and the scales. I used to attach the front and rear bolsters and then try to fit the scale in the middle, but I find this front to back, one-joint-at-a-time, approach much quicker and the resulting joints much tighter. There's no measuring angles, test fitting, adjusting, . . . This method is just grind, clamp, drill, screw and move on to the next piece. It's really helped lower my blood pressure.
The final pic of the day shows all of the parts laid out. Everything has been shaped, drilled, countersunk, and tapped. The next step will be to get the pivot pin in place and profile the whole knife together to true everything up. But, that will have to wait until next week.
I hope you enjoy following along with me on this build. I'm looking forward to seeing how these Micarta scales work out. I've only used Micarta once before and was very pleased with how easy it is to work and how it looks as a finished product. Plus, Micarta has the added bonus of being completely stable. That means no moving, checking, cracking, or cupping. It's good stuff. Thanks for stopping by the Robinson Edge.
- Brandant Robinson
No comments:
Post a Comment