Monday, August 31, 2015

Shaping the Handle

I made a little progress on the "Panther" knife over the weekend that I thought I would share with you.  Most of my efforts were put into fitting, shaping, and polishing the handle of the knife.  Up until now, the knife still looks like a couple of blocks screwed together, but after the handle gets its shape, it really starts to look like a knife.  I also get a chance to see how the knife will feel when it's held in the hand.

The next step before final handle shaping is to fit the pivot pin so the blade can be attached.  In order to conceal the pivot screws, pockets need to be recessed into the backsides of the front bolsters.  With the bolsters attached to the liners, I use a black marker to indicate the location of the pockets.

This picture shows the backside of the bolsters where the pockets have been drilled into the steel.  It also shows the barrel pivot that will be used for this project.  The pivot pin has been ground to length as well.

As I shape the handle, I will also be establishing the fit of the blade in its open position.  Therefore, I need to adjust the spacer length so that the blade stops in the proper location.  To do this, I blacken the tip of the spacer with a black marker, set the blade in the desired open position, and scratch a mark with a razor blade.  I then grind the tip of the spacer back to the line.  Simple and easy.

The last thing I need to do before assembling the knife and shaping the handle is to add the thumb notch to the left bolster and scale.  Using the notch already cut into the liner, I use my spindle sander to grind the groove into the bolster and scale.  I also use the sander to shape a small contour around the groove for comfort.

Everything is assembled and I'm ready to grind the handle down to shape.  Remember that I left the bolsters and scales slightly over sized.  These parts will be ground down until they meet with the liners in a seamless fashion.

The handle has been ground down to its final profile and the surfaces of the scales have been ground down to meet in the same plane as the bolsters.  In the photo, I have laid the knife on the pattern to check everything out.  Seems to be a good fit with the lines right on the money.

I begin shaping the contours of the handle with an 80 grit belt on the grinder with a slack belt attachment.  This is when I can check to see how the finished knife will feel in the hand.  This one feels great.

Here's a view of the spine.  Everything gets rounded over for comfort.  Also, notice the complete absence of gaps between components.  Nice!

I progress up through the belt grits up through 3000 grit on the grinder and give the handle a final polish on the buffer to polish out any scratches.  I took this knife up to a full mirror polish.  I might add a hand-rubbed satin finish, but I haven't made up my mind yet.  Also, the Micarta polished up really nicely and looks great.

Since I am going to add some file work to this knife, the blade needs to be filed before it is hardened.  I color in the spine with a black marker and scratch reference lines at 1/8" intervals to help me keep the pattern regular.

For the blade and spacer, I chose a pattern I call the alternating twist.  It's a very attractive pattern that is comprised of four round grooves at 45 degrees, followed by four round grooves at 45 degrees in the other direction.  It's easier to see than to explain, unfortunately my phone doesn't take very good closeup photos.  The above shows the first four grooves filed into the spine of the blade.

This photo isn't too bad.  It shows the second set of groves in the spine.  The pattern will change directions again and proceed down the spine.  I think it's an attractive pattern that, when polished up, really catches the light from many different directions.

The spine of the blade is finished and the spacer gets the same file work pattern to match.

With the file work done on the blade, it's almost ready for heat treatment.  The last thing I do before gift wrapping it is to enlarge the pivot hole with a #14 bit.  After heat treatment, the hole will get reamed with a carbide reamer to 3/16" so that it will accept a 3/16" bushing.  This photo shows the blade wrapped in tool wrap and ready to get cooked.  I hope to get some time during the week to fire up the oven and get this blade hardened and tempered.

Thanks for following along with me on this knife adventure.  This knife is a fairly simple and classic design, but with the file work on the blade, spacer and liners, it should look really snazzy.  Stay tuned.  There is plenty more to come.  Have a great week.

-  Brandant Robinson

Tuesday, August 25, 2015

Let's Start a New Build

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

Monday, August 17, 2015

The Pride Knife Finished

In this post, the Pride knife gets its final touches.  This was a fun build and I gained a lot of experience that I will be able to implement in future knives.  Without further adieu, here are the finishing steps for the Pride knife.

This is where we left of from last time.  The contour lines have been cut in by first using a diamond wheel in a rotary tool and finished off by hand filing. 

After sitting on things and studying the knife for the last week, I made the determination that I was varying too far off my original intent of keeping this knife clean and simple.  After come to this conclusion, I made the determination to remove the intersecting lines and keep only a single curve through the center of the knife.  I have indicated the areas that will be removed in the above photo with a black marker.

Using a 1/2" sanding drum in my Dremel, I cut into the steel at the previously determined line.  At first, I am only trying to establish the depth of the cut at the curved line.  This process effectively "lifts" the curve off of the surface of the scale.

Here is what the handle looks like after making that initial pass.  I was actually quite surprised at how fast the steel was removed using this technique.

Next, using my diamond cut off wheel, I reestablish the curved line and smooth things back out.

This photo shows the progress after the lines have been smoothed out.

After spending some time with the 1/2" drum, I lower the entire surface of the section and even things out a little.
I repeat the same process on the front area of the scale until things are all evened out.

Now that the curve is raised and established, I can add some texture to the lowered areas.  I debated a bit on how to accomplish this.  I chose to make tiny cuts with the diamond wheel over stippling with a flame tip bit.  Stippling with a flame tip gives small, round dots, and the diamond wheel gives tiny little lines.  The reason for using the diamond wheel was to be able to orient the little cut lines with the curve to not only add texture, but to also continue the flowing look of the curve through the texture.  I think it really adds a lot to this piece.

The above photo shows the front area after it receives some texturing.  I also repeat the whole process for the right scale to complete the carving and texturing work.  At this point, the knife is practically done.  The only thing left to do now is to clean it up a bit and give it some hand-rubbed attention.

And here she is in all her glory!  Everything is finished up to 600 grit and hand rubbed until things flow together.  You might also notice that I smoothed out the indentation for the thumb stud ramp.  This little divot helps guide one's thumb to make opening the knife really comfortable.  The blade also got its edge put on.  Because of the thin edge geometry, sharpening went really fast.  I had fun making fine ribbons of cardstock paper as I checked the edge for any flaws.  Man, I tell you, it's sharp and seems to hold a great edge.
Here's a shot of the spine.  Not much to see here since I chose to keep things simple and not add any file work.  I'm glad I made that choice.  The knife is fairly thin, but is still really comfortable in the hand.

This is a look at the bottom of the knife.  Again, not much to see except to show a nice, early lockup.

This final pic shows the back side of the knife in the closed position.  You can just see the thumb stud screw head, which is the only visible hardware on this knife.  I've peen thumb studs into blades before for a seamless fit.  If I had to do it over again, I think I would have taken the time to do it with this one as well.  I'll make a mental note for the future if I decide to make another knife in this manner.

I have to say, I truly enjoyed this build, even more so that most.  It was a fun experiment into the unknown and I chalk this one up in the "win" category.  I think it turned out really nice.  It would say it has some simple elegance to it.  I will be posting it to my available knives page soon, so check back if you are interested in adding it to your collection.  

As always, thanks for following along with me on this knife-making adventure.  Now, back to my design notebook to decide on what to build next!

-  Brandant Robinson

Monday, August 10, 2015

"Pride" Gets a Thumb Stud and some Curves

I had a family reunion last weekend which kept me out of the shop for the most part.  But, even with the family frivolities, I did manage to make a little progress on the Pride knife.  Here's a look at the progress that was made.

The majority of my weekend shop time was spent in manufacturing a thumb stud for the knife.  I know that may will buy pre-made thumb studs, but I really like to make my own to my own design and standards.  As I have stated in the past, I do not have a metal lathe, so all of my turning work is done on my mini wood lathe using files and sandpaper to do the shaping.  Here you can see a piece of 3/16" round 416 stainless steel rod mounted in a Jacobs chuck on the lathe head.  I gave the rod a spin and flatten off the end with a flat file.

Because I am taking progress photos with my phone, this is about as close as I can get to the action before everything goes out of focus in a hurry.  You might be able to make out that I have painted the end of the rod with black marker and scratched the desired length of the thumb stud for reference.  Now that I have a flat spot on the end of the rod, I insert another Jacobs chuck into the tailstock of the lathe and clamp down on a #56 drill bit.  I expose enough of the drill bit to drill the hole as deep as possible without drilling beyond the overall length of the thumb stud.

After the hole is drilled, it gets threaded by hand with a 0-80 tap.

Here I've used a hack saw to cut into the rod at the top of the thumb stud so that I can see the material that I have to work with.  In the photo I'm checking the length once again with the end of my calipers.

Since there really isn't much to see at this resolution, I'll just explain what I have done in words.  Using a set of needle files, I have given some shape to the thumb stud until I'm pleased with the outcome.  I use mostly 1/8" round and three-corner files to do this work.  Once the shape has been cut into the rod, I give it a good sanding to knock off the sharp edges and polish up the piece.

If you squint really hard you might be able to see the screw threads sticking out of the end of the thumb stud.  This is a sacrificial 0-80 screw that has been threaded into the tapped hole and had its head cut off.  You'll see why in the next photo.  At this point, I part off the piece from the rest of the rod with a hack saw.

Now you can see the value of the sacrificial screw.  The threads get mounted into the Jacobs chuck so that I can spin it and finish up the head of the thumb stud.  Since I finished the blade up to 600 grit, the thumb stud will get the same treatment.

Here's a photo of the finished thumb stud.  I sometimes get a little elaborate with my thumb studs, but I elected to keep this one simple and sleek, keeping with the overall theme of the knife.

And here she is, mounted in the blade.  I use a small 0-80 button head screw to make the attachment.  The hard part is grinding down the length of the screw so that it's just the right length.  But, with a little perseverance, I got it done.

The knife is now at the point that it's time to begin work on the embellishments.  I have drawn on the scales a series of overlapping curves that I will use for the basis of my carving and texturing.  I sure hope this works out.  This is all new territory for me.  It would be a crying shame to mess things up at this point in the game.  Oh well, to the brave go the spoils I suppose.

Using a diamond cutoff wheel mounted in my rotary tool, I cut in the curves.  I was shaking like a dog passing razor blades as I tried to keep the curves smooth.  The cuts are a little jagged in places, but I'll clean those up in the next step.  After mopping off the sweat from my brow, I took a moment for my blood pressure to come back down to normal range.

With the basis of the lines cut in with the Dremel, I use a round needle file to start cleaning up the bottom and sides of the cuts.  This worked surprisingly well to even things out.

Here is a final photo of the weekend's work.  The lines are not as smooth as they need to be yet, but they are much better than they were before using the file.  I still have quite a bit of work left to do to get them completely cleaned up, but I can see that my methods are going to work.  My intention is to flute the spaces between the curves and to stipple texture the negative spaces between.  I think this will give the plain stainless scales some real style.

Thanks for following along with me on this build and for stopping by the Robinson Edge.

-  Brandant Robinson