I hope everyone enjoyed their weekend as much as I enjoyed mine. It was a good end to a long and stressful week. I find my time in the shop very restful and therapeutic, a nice diversion from the real troubles of life.
First off, I was able to get my little Glaucus knife completed, but I'm determined to take some good photographs of it before posting the final pics. I plan on making a good light box to take photos of my knifes in. I think that might be a big step for me in producing a good image of my work. But, since I didn't have all the materials on hand to build the light box, I made the decision to start on my next knife.
I decided to make another Bobcat design knife. So far I've made two knives of this design and have received some very positive feedback from their new owners. So, with that information, I made up my mind to make another Bobcat knife and make it something special. Without further adieu, let's get started.
Here is the starting point for all my knife builds, the raw materials. Even at this point in my knife-making adventures I am still amazed that these chunks of steel, titanium and wood are destined to become a beautiful and functional tool. The materials of choice are 6AL4V titanium for the liners, 416 stainless for the spacer, Damasteel "Dense Twist" for the bolsters, and stabilized buckeye burl for the scales. Not pictured is the CPM154 blade steel. I slipped out to my shop the night before and profiled, hardened, and cryo treated the blade. At the time of this photo, the blade was in my heat treat oven undergoing its second temper cycle.
The big chunks of material have all be cut into smaller chunks. The rough-cut parts are now ready to be refined and shaped into their respective components.
The liners have both been profiled and all the holes drilled in the appropriate locations for assembly. The spacer also has corresponding holes drilled through it. The scales have been rough cut, matched, and the dovetail ends have been ground at 30 degrees.
I decided to try fitting the bolsters and scales a little bit different this time. I thought I would start with the scales in the middle and work outward. This photo shows the scale of one liner pinned in place.
I left the bolsters unshaped so I would have a little wiggle room for fitting. the mating face of both bolsters have been dovetail ground at 30 degrees to match the scale and set in place. Each bolster will get clamped to the liner and drilled to locate the screw holes in the right places.
All the parts have been drilled, countersunk where appropriate, and tapped to accept 0-80 machine screws. The blade is also done tempering and gets its photo debut.
The bolsters and scales are all fastened together with screws and ready to be profile ground. Assembling the handles in this manner gave me some extremely tight joints. There is no daylight in the joints of this fit. Awesome!
After a few minutes on the grinder, the handles have each been profile ground.
Time to build the pivot mechanism. The photo above shows the parts and necessary tools to perform this step. The parts that make up the pivot are the pivot pin and screws, a stainless steel bushing, and two washers. The essential tools are the pivot lap for refining the length of the pin and bushing, and the micrometer for getting the lengths exact. I didn't take progress photos, but the process for building the pivot goes something like this:
1. polish the washers all bright and shiny. 2. stack the washers on the blade and take a measurement of the thickness. 3. lap the bushing to the thickness of the blade plus the two washers. I usually add about 1 to 2 thousands of an inch to this measurement for clearance. 4. lap the spacer to the same thickness as the bushing. 5. lap the pin length down to fit the width of the pivot plus the thickness of the liners.
That's basically the process I follow for pivot assembly. It's absolutely necessary to "nail the numbers" when building the pivot system if you want a smooth action. A few thousands too few or too many lead to a tight action or one that is lose. It's a little fussy, but definitely worth taking one's time to get it right.
Here's a shot of the parts waiting for their first assembly. With the exception of a thumb stud and screw, this is essentially the whole knife. A lot of refinement and detail happens from here, but at this point all of the pieces of the puzzle are on the table.
The knife is put together for the first time. I did dialed in the open and closed position of the blade before assembly, but didn't get any photos of that. It's easy enough, just grind off the front of the spacer until the blade opens to the right position and drill and install the stop pin to keep the blade edge from contacting the spacer in the closed position. The action of this knife is silky smooth and will only get better as the blade tang gets polished up.
With the knife assembled, I can start working on the overall shape of the handle. I round over the sides of the knife to give the knife a nice appearance, but most importantly a comfortable feel in the hand. Here is the knife after grinding up to 220 grit. It's hand sanding from here on out. I will take it up to 1500 grit and give the bolsters a quick buff to get the Damasteel ready for etching.
Here is a look at the spine of the knife. Everything fits nice and tight. Zero gaps is the goal. I don't worry about polishing up the edges of the liners or the spacer at this point. Those parts will get fileworked soon, so no need to get a high finish until that work is accomplished.
Well, that about does it for this week. Tune in next week when I should be able to get the blade finished and begin the detail work. Thanks for following along with me on this knife-making adventure.
- Brandant Robinson
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