Saturday, May 23, 2015

More Progress

I was able to squeeze in a couple of hours worth of work on these two "Virtue" knives.  I managed to make some pretty good progress too.  There is still a whole lot of work left to do on them, but every step gets me closer to the finished knives.  Here's what I was able to accomplish today.
These are the two back spacer for the knives shown above.  You can see that I have drilled several holes through them.  The reasons for this are to reduce the weight of the knife and to make surface grinding them to final thickness a little easier.  I don't have a surface grinder, so this gets done on my horizontal disc grinder and finished up on a surface plate with sandpaper glued to it.

Next, it's time to set the stop position of the blades while in the closed position.  In the photo above, you can see the stop pins and the blades in place on the two knives.  If you look closely, you can see that the blade tips are not set into the handles far enough to keep the blade tucked safely away when closed, and that's not good.

In order to seat the blades in deeper, the tang needs to be ground a little more on each blade.  This is done with a 1/4" grinding drum mounted in a rotary tool.  It's kind of a slow process and requires several cycles of grinding and fitting to get the blade to close just right.

There, now that's better.  The tip is now concealed inside the handle and the blade stops before making contact with the spacer.

With the open and closed positions dialed in, it's time to get started on shaping the handle on the bolstered knife.  To begin, I like to start by chamfering the outside edge of the handle at 45 degrees.  The chamfer helps me keep the shape consistent as I round off the edges.

Here's the handle after the bolsters and scales have been rounded off on the grinder.  I use a slack belt to work the edges and the flat platen to smooth off the sides.  I finished the handle up to 400 grit on the grinder, the remainder will be done by hand.

Here's a shot of the spine of the knife.  I must admit, I've never really liked the looks of colored liners underneath scales.  That said, I think these actually look kind of classy.  And check out the fit of those dovetailed bolsters.  Nice!

That's about as far as I was able to get today.  The next steps will be to shape the other knife and to add any file work to the blades before they get heat treated.  If everything goes right, I hope to get that done and the blades heat treated on Memorial day.  I think these knives are coming together nicely and I can't wait to get started on the detail work.

Thanks for stopping by the Robinson Edge.

-  Brandant Robinson

Saturday, May 16, 2015

Building the Pivot

This weekend was filled with fatherly duties, so the time I was able to spend out in my little shop was quite limited.  In spite of that, I was able to make a little progress on the two knives that I'm working on.  Since I haven't shown how I build my pivots, I took some progress photos of how I achieve this, the most important part of a folding knife.  After all, if the pivot doesn't work right, you don't have a folder.

This is where we begin, with enough parts to complete two pivot systems.  My pivots are composed of a 3/16" bushing, two 1/2" washers and a 1/8" pivot pin and screws.

Here is what the system looks like.  The blade has a 3/16" hole drilled through the tang.  The bushing fits perfectly in the tang hole and will be lapped until it is the exact width of the tang plus the washers.  The pivot pin then passes through the bushing and will be trimmed to length and tightened down with the screws to hold the assembly together.

First, we need to determine the thickness of the blade tang and the washers in order to know the needed length of the bushing.  I use a pair of digital calipers to take this measurement.

Here is the little gizmo that makes lapping the bushing to length easy.  I bought this pivot lap from USA Knifemakers.  The bushing fits into the bottom of the puck and the plunger is pushed down as the whole thing is rubbed on some abrasive.  It works pretty slick.

To hog off long sections of bushings, I used the pivot lap on my shop-built horizontal disk grinder.  I check the length of the bushing often, and when it gets close to the desired length, I switch off the grinder and hand sand the bushing to final size.


Next, the blade tang needs to be fitted to the back spacer so it is in the correct open position.  I leave the spacer long so that it can be adjusted to the correct length.  To do this, I black out the tip with a black marker and use an Exacto knife to mark where the spacer needs to be trimmed to.

After a little grinding, the blade stops in the correct open position.  Check another step off the list.

The screws of the pivot come from the supplier much too long.  I developed this little jig to shorten screws in a short time.  It's just a square piece of titanium that has a tapped hole in it.  I screw the pivot screw through the jig to just the right length that I need.

On the back side, I use a pair of wire cutters to nip off the end.

The screw gets lapped on the disk grinder, giving me a screw of the perfect length.

Next, it's time to get the pivot pin trimmed to correct length.  To do this, I assemble the knife with the pivot system in place as shown above.

A quick spin on the disk grinder takes the excess off of the pivot pin.

The last step to complete the pivot assembly is to deal with the pivot screw heads.  For the bolstered knife, pockets get drilled in the back sides of the bolsters which will allow the screw heads to be concealed below.  The titanium scales get a through hole that the screw heads will fit into.  The above shows the end of this step.

Well, not a lot of progress made this weekend, but that's alright.  Next week should bring about a lot more progress.  I look forward to seeing how these two knives turn out.

Thanks for stopping by the Robinson Edge.

-  Brandant Robinson

Saturday, May 9, 2015

The Beginning of Two "Virtue" Knives

Well, it's about time that I got out to my shop and made some sparks.  I've been overwhelmed with spring chores for the last few weeks, not to mention suffering through the flu for two full weeks.  That was no fun at all.  Being sick does make one grateful for his health when it returns.

My next endeavor is to build two knives which I intend to make available for purchase.  I still need to recoup some funds from my grinder build.  By the way, I don't know how I ever got by without a 2"x72" grinder.  It really makes many of the jobs a breeze and has truly sped up my build process. 

I usually like to make one knife at a time in order to focus on the details of that knife.  This time around though, I decided to make two knives at the same time.  I wanted to make another knife like the one I've been carrying for the last year, a design that I call "Virtue," and make it available for sale.  I had two ideas for the same design kicking around in my brain, and since I couldn't decide on which one to make, I elected to make them both.  I hope I can keep all the parts separate since they are both very similar.

Here's the beginning of the two knives.  At the top of the photo you can see a picture of the shape of the "Virtue" design.  I really like this little knife for its utility and comfort in the hand.  It fits perfectly in your pocket too.  You can see the two blades have both been profiled from CPM 154 steel.  The other three items in the photo are two sets of liners and a set of scales that have been temporarily super glued together for profiling.  These are all cut out of 6AL4V titanium.  The first knife design will have these titanium scales which will be textured and carved.  This should make for a very light weight and slim design.  It will also have a lanyard hole at the back for a leather thong.  The second design will have both front and rear bolsters with scales between.  It will also be fitted with a pocket clip like the one I carry everyday.
I tried something a little different than I normally do when it comes to profiling.  This time I elected to glue the paper patterns onto the pieces instead of tracing the pattern onto them with a Sharpie.  I've seen many other makers do this and thought I would give it a try too.  It worked pretty well, except for the fact that I couldn't dunk them in water to cool them off while grinding.  The jury is still out on whether or not I will add this step to my future builds.

After much toil and labor most of the parts are ready to be fitted.  I didn't take any action photos along the way (I should probably do a better job of taking pics) but there was a lot of drilling, tapping, counter sinking, grinding, and fitting screws.  You can see in the top, right corner of the above photo two scales for knife #2.  I've had a set of mammoth ivory scales for some time now that have been waiting for the right knife.  I really love the looks of this mammoth, but they were really thin.  I decided that this knife was the place they needed to be, so I glued some dark red spacer material to the backs to make the scales thick enough to use.  I think they will look great when they are done.

Above you can see the liners have been fitted to their scales and bolsters.  I grind the profiles of each piece down very close to the finished shape at this point.  I still leave just a tiny bit extra for final fitting once they are assembled with the spacers in between the liners.  You can't see it in the photo, but the bolsters and scales on the left knife have been dovetailed into each other.  I dovetail at about 30 degrees, which gives it just the right look in my humble opinion.  Don't you just love that mammoth?

At this stage, the handles are completely assembled and the final shape has been established.  I think you can see how both are of the same design, but the final products should be truly unique.  The blades have been places loose in the handles just to see what the finished knives will look like.  Looking good!

Here is where I ended for the week.  Lots of work equals lots of parts.  The next step will be to do any file work on the blades before they get heat treated.  I plan to embellish the bolstered knife with lots of file work, but I'm thinking about leaving the titanium scaled knife "Au Naturel".  I think it will look really sleek with everything all smooth, but I haven't made up my mind yet.

I hope you enjoy following along with these builds.  By the way, these are knives #23 and 24 if you are interested in knowing.  I think I've finally fallen into my own style of building a folder.  Most of what I have learned about folder building I have skimmed off the internet and adapted to my tools and my own style.  Some day I'm going to have to find another maker and visit his shop and compare notes.  Thanks for stopping by the Robinson Edge.

-  Brandant Robinson