BARR KNIVES

ESSAYS ON THE LEARNING PROCESS

• Metal Cutting
• Mistakes
• Machine Tools
• Grinders

Sometimes the lessons all pile on at once and build toward a climactic combination of mistakes that stops all further work in its tracks, at least for the day and sometimes longer. Sometimes I am immediately hopping around and cursing, other times I just sag, not only my shoulders, but my entire body sort of sags accompanied by a surreal calm, as a wave of defeat washes over me. Most recently it ends up as the latter since my shop is getting crowded enough to discourage flailing about.

It seems that the farther I go in any enjoyable field of endeavor, the risks are ever increasing. Not necessarily bodily risks although there certainly some physical risks. The best machines for doing some jobs are only capable of performing the most basic process, but with absolute accuracy. I try to aim the basic process at my part, often eyeballing the set-up and taking the chance that what I am doing will work. There is no operator's manual for my 1940s vintage milling machine, so I'm kinda shootin' in the dark sometimes.

I watched a 5-inch diameter metal-cutting saw bind and break from getting wedged into a piece of mokume-gane that I had painstakingly heat fused. The saw bound up because it was moving sideways in the work, which is a no-no for that type of saw. It moved laterally while I was making the cut enough to finally bind up the workpiece. Many lessons were learned, oh joy. The vortex of doom sucked up about $180 in tooling that morning. This kind of big screwup can sometimes be attributed to a state of mind, but I had thought my state of mind was okay at the time. It was morning and I felt rested and alert. I had no idea what the lesson ahead would entail.

My milling machine interfaces with the world with a Browne & Sharpe #9 tapered socket. It spins around with consummate authority adjacent to a 5x23inch table that is movable in three dimensions. I put sharp things in the tapered socket and then mount a workpiece to the table. The sharp things generally have straight shanks or otherwise need to be interfaced with the tapered spindle. I needed the sharp thing to be a sawblade this time.

Everything seemed so elegant and straightforward with these parts. The first was a toolholder with a tapered socket that fit into my mill. The toolholder would hold a precisely ¾ inch shaft.

The other, called a stub arbor, has a ¾ inch shaft on one end, the other end had hardware to accommodate saw blades with 1-inch diameter holes. The stub arbor fits into the toolholder. When I first put them together on my milling machine, their fit was almost airtight, and I giggled with delight because the fit was so perfect that as I pushed the arbor shaft into the toolholder the air trapped under it makes it squishy, like a little shock absorber. Things that fit together that well just really get me goin'.

This precision tapered shaft and socket fitting is common in machine tools and was probably used originally for simplicity and its sure grip. There are many taper standards and my milling machine uses a Brown & Sharpe #9 taper, my lathe a Morse #0. Neither of these is in common use anymore, my lathe is at least thirty years old, the milling machine at least fifty. Their age and semi-obsolescence of their tapers limits the variety of tooling which can be obtained for them, which in turn limits their utility, the milling machine to a greater extent. I can still do anything I need to do for knifemaking; I just have to learn how to use the machine.

METAL CUTTING

I can cut metal in any number of ways, from abrasive belts to slotting saws and broaches and each way has its advantages and disadvantages. Many types of blades even demand that the cutting path be a straight line. Saws and broaches can only travel in a straight line, and they make really nice straight cuts. Endmills have a structure that is all blades and they can change direction without undue stress to the tool. If you try to change the direction of a disc type cutter while in the cut, bad things happen. If you've ever done it with a skil-type wood saw then you know what I mean. All it takes is one saw tooth caught and the whole saw is jammed, the motor valiantly trying to free itself until you back off of the power switch or something breaks, whichever comes first.

In milling operations the novice (me) is always breaking tooling. The distinction between enough force to make a good cut and enough to break the cutter is sometimes very fine. I haven't escaped the rookie syndrome; I just have to pay for the stuff myself, instead of learning the hard lessons at an employer's expense.

The previous is just what happened to my mokume billet while I was slotting it for use on the knife. My nice new toolholder has a setscrew that engages a flat spot on the stub arbor and keeps the arbor from spinning inside the toolholder. Setscrews are nothing new to me; I have used them replaced them and made new ones all over my shop and even have a good supply of common spares. I also have all over my shop those little folding Allen wrench sets, because I always need them. The setscrew on my new toolholder is three eighths of an inch in diameter, half again as large as any other I own and uses the largest key on my little folding set-o-wrenches. Unfortunately I didn't tighten it down like it was the toughest tightening job the little wrench set might ever come across. I've stripped out a few screws in my life and I'm sure I tightened it a safe amount for a one-quarter inch diameter screw. I didn't go to German spec, gutentight and it loosened up.

MISTAKES

When errors happen it's in the planning and setup of the cutting operation. The cutter removes metal precisely, completely and doesn't go backwards. If the work-piece gets too small once, no amount of cutting will make it right. For this reason the utmost care must be taken when setting up a cut in a milling machine or lathe. The path of the cutting tool must be considered to ensure it doesn't intersect with anything other than the workpiece. I don't want to cut big slots in my vise, no matter how nice and straight they are. There must also be adequate clearance around the table, vise, and cutter arbor, so that the major parts of the machine don't try to occupy the same space and time coordinates. That is known as crashing the machine and it has much greater consequences than crashing a computer. When you crash a lathe there is not only the possibility of major damage to the lathe, but the evidence of that damage is gonna be there forever. You can't just C:/format and start fresh. Everybody who comes and looks at your machine will be able to tell that you made a rookie mistake and crashed it.

My rookie mistake was not tightening a setscrew, which allowed the cutter to get out of alignment with respect to the workpiece. The cutter bound in the work-piece, and soon broke. "Rrr rrr rrr ching!" And I'm now looking at a broken five-inch diameter cutter and slightly mauled billet of mokume-gane. Ouch!

And worse, the stub arbor, while spinning in the toolholder in an unauthorized manner, got stuck in the toolholder. I mean really stuck. It took over an hour, a good sweat, and the aid of multiple wrenches, hammers and smooshed fingers to separate all of the pieces that had fit together so nicely and effortlessly only moments before.

With the exception of the loose setscrew, the only indication of trouble before the crash, was the sound. It was!. different, wrong somehow, and maybe I should have stopped the machine as soon as the sound of the cutter changed significantly. But I am still early on in the process of learn to use this kind of cutter. After picking up the carnage and receiving a new toolholder via mail order, I substantially changed the configuration of that cutting operation, modified my milling machine vise and tried again on a test piece of brass. This time I was able to slot the brass to fit the knife to a very close fit. Excellent, although the mokume-gane has had its ass kicked, and I will leave that challenge for another time. After all, the customer for this knife is me, and I am trying for optimum fit and finish, but the continued use of mokume-gane will make the project run overtime and cost me even more materials, which I cannot afford. So you guys are just gonna have to be impressed by my scrap pile.

I have plenty of brass ready to use, and it will show my fit and finish just as well as the mokume-gane, but will decrease the potential selling price of the piece by two hundred to four hundred dollars. I can live with that until the next time I get to try it. So if you want the knife, just leave $600 in the box.

MACHINE TOOLS

A great part of learning to produce art with machine tools is learning the particulars of the machine. I am a regular reader of the rec.crafts.metalworking newsgroup, which is populated by a wide variety of home shop machinists. The people on that newsgroup are always looking for deals on used machine tools. It's no surprise since most crafters cannot afford and do not need new, state-of-the-art equipment in order to fix the pool pump or turn their own brake drums. I decided I needed a milling machine to cut straight lines and slots in metal, and a mill is the best way to do that. When I talked to knifemaker Chris Reeve at the Oregon Knife Collectors Association show some years back he told me I needed a knee mill. I had no idea what he was talking about and thought it was niemil, but I remembered his words. He also gave me a few brand names Bridgeport and Lagun were quality machines, he said. It turned out that Bridgeport makes a machine that is universal in the machining industry and has been the source of clones produced in Europe, the U.S. and most recently Southeast Asia. The "knee" on a knee mill sticks out of the front of the machine and holds up the worktable, which holds the piece to be machined. The knee is on vertical bearings or "ways" and can move up and down relative to the main casting of the machine, which houses the spindle. The worktable is on similar horizontal ways, which allow it to move left and right, and fore and aft atop the knee, which moves the whole thing up and down relative to the spindle, which holds the cutting tool. The entire assembly is very rigid and allows anything mounted to the table to be moved across the cutter in a very straight line. This makes possible very straight, smooth-sided cuts in steel, which is not something I can do by hand. I can make curved cuts by using the radius of the cutting tool, or by using two of the axes at once, but the latter generally doesn't come out too well. It's kind of like using an etch-a-sketch to draw a curved line, it never works quite right, and you don't just turn your milling machine upside down and shake it to reset it.

I had called the Bridgeport Company and learned that a new Computer Numerically Controlled (CNC) mill would cost about $17,000 with only about $3,000 of that going for the electronics -- more than I wanted to pay for such a specialized tool, but I was considering it. Within a matter of days, my lovely wife surprised me with a very nice motorcycle of about that same price. With that purchase, my path of machine tool acquisition turned away from new machinery.

Since there really wasn't another $17,000 lying around, I had to figure some way to get good machinery other than buying it new. And a brand new motorcycle did provide some distraction from my suffering...

I began to scour the classifieds for used machinery and found a lathe. It's a small Sears Craftsman lathe, probably from the 1960s. It was basically a one-owner machine and it showed little wear, just a bit of neglect. It needed a motor and a few other things, but was good enough for $500 and I brought it home. After mounting it to a thick steel plate and getting a motor for it, it has served me well -- the manual that came with it has proven invaluable, despite its being older than I am. I have since used it for countless home repair and knifemaking tasks. It has been surprising how useful the lathe really is and my only regret is that I didn't get a bigger one.

Here is my little lathe in the process of turning an improbably large piece of steel.

The milling machine came later. I couldn't find anything for less than $2,000, which is what I was willing to spend on the initial purchase. One rule of thumb for buying machine tools is that you will likely spend the cost of the machine in accessories or "tooling", so I also had to consider the cost of accessories. I found my mill in the corner of a friend's shop. He has his metalwork business in a big shop and is constantly buying and selling machine tools. In a lonely corner was this Vernon #0 horizontal mill. If exclusivity were a goal, this machine would probably be the rarest of the rare. That wasn't why I bought it, though. I bought it because there was an identical machine in J.P. Moss's shop where I spent a week learning the rudiments of machining. I called J.P. and to ask him if this was a good buy at $500. He said, "Buy it!" I brought it home and put it into a corner of my garage. It is a stout little machine of WWII vintage and had most recently been used in a college metal shop.

Bringing the mill home was of course not enough. Before it could be run it needed some repair. The drive motor in it also required three-phase power, which is unavailable at my house. Three phase power is used in industrial machinery because more power can be transmitted through the same size wire using three-phase than household single-phase. Three-phase motors are also reported to run smoother at high power outputs as in heavy milling or turning. This prompted research on how best to tackle the machines' requirements. I chose to make my own power converter from a three-phase motor, switches and capacitors. Mostly because I didn't know how, and I wanted to be able to do it, and being a cheapskate is somewhere in there too. I found an electrical schematic on the web and found the parts I needed. About one hundred sixty dollars and a few hours later it was completed, and the mill would run. My mill and lathe were working just great in the garage.

One of the next things I learned that is characteristic of horizontal milling machines is that when they are cutting, they throw a rooster tail of metal chips about four feet long from where the cutting is happening. While under most circumstances this is reason to hoist a celebratory brewski and belch one's appreciation, it wasn't quite right just yet.

We use the garage as our main household entrance. I had to move the machines into the basement, since my wife didn't appreciate the little razor sharp bits of metal being carried into the house on the bottom of all our shoes. Sure, no problem. We had the local sign company bring out their boom truck and lower the mill down the outside stairwell. It weighs 800 pounds and would have crushed any household wooden stairs trying to move it. Well, it seemed easy because I wasn't home for it, but it got done and everything works fine downstairs now.

Of course, the mill is working fine with some qualifications. Now that I could plug in the machine, I could begin to familiarize myself with it and figure out some ways to get work done with it. The more I use it, the more useful it becomes.

The lathe is fairly well set up to do some work. I just needed to learn what it is capable of, which I'm still learning and probably will be for a long time.

A lathe works opposite the way a milling machine does: the lathe moves a semi-fixed cutting tool about a spinning workpiece, while the milling machine moves the workpiece in relation to a spinning cutter. The shape and composition of the workpiece determine the optimum rotational speed and the cutting tool geometry. The correct speed and feed will help tools stay sharp longer. The lathe came with three and four jaw chucks, a faceplate, and drill type Jacobs chuck, and was prepared to hold onto many different types of workpieces. Cutting tools for the lathe were also easily found. Forty-five dollars on an EBay auction netted me several toolholders and some of the hardened steel bits used for cutting, plus a few other hunks of metal that have proven useful at one time or another. Those hardened steel bits are ground to the shape needed for the job, so as long as they fit in the toolholder, I can make them work by grinding them how I want them, as suggested by the Manual of Lathe Operation that came with my lathe. Not a lot of forty-year-old things that you buy come with an owner's manual as good as this one, but I just got lucky.

The milling machine has been a much greater challenge, even though I believe my mill to be particularly versatile for its size. It has a very small footprint: it only takes up two-by-three feet of floor space, is five feet tall and weighs 800 pounds. I can envision it doing some pretty large work because of the simplicity, strength, and the openness of its design.

The peak frustration moment with any given tool, like with the mokume-gane, is inexplicably followed by a dramatic increase in my ability to utilize the tool and the tool begins to fade into the background. It just happened with my milling machine, very dramatically and it has happened with all of my other machines as well. The first real machine tool I bought was a small, bench-top type drill press. Its little table shows the scars from when I drilled into it instead of orienting the table so the drill would pass through the hole in the table. It was ten years ago, and I'll bet I hopped around and cursed a bit then.

GRINDERS

It doesn't always happen in one drilling, cutting, crashing moment. I have three abrasive grinders, two of which I paid top dollar for because they are professional-quality machines. They were my second and third grinders and I learned that professional quality machines do very little by themselves toward producing a quality product. I made a few knives shortly after I got the machines and was very disappointed with the results. My work still looked pretty badly (to me), compared to what I have seen produced by people with lesser machinery. I tried many different things to get the machines to do what I wanted them to do, but I kept getting poor results. After my week with J.P. Moss, I found a million uses for each of them and can no longer imagine living without a variable-speed adjustable-table vertical disc grinder. I just didn't know what I was missing.

I have 2 vintage motorcycles that always need some attention. I also repair all the home appliances and do much of our auto repair. I have found that having all the tools and skills for knifemaking has made me much handier at repair as well as improving the things that I have. Before I was handy, now I'm Captain Handy. And I would hate to be without either of my grinders, or lathe, or the milling machine, or the drill press, or the band saw, or the furnace or that big Kennedy toolbox of neat measuring and layout tools. I'm not even going to go into the big red rollaway toolbox that I have in order to keep my two quarter-century-old Italian motorcycles on the road.

There are also times when I learn that getting equipment to do a job myself can actually be a detriment to getting the job done. Such was the case when I bought myself a drill-sharpening machine. Before I got my furnace, I had no place to soften blade steel for drilling. That meant drilling any needed holes in the knife in whatever state of hardness the blade steel came in. For some steels it was no problem, but for others the drilling process was murdering my drill bits. When I last made a batch of knives from 1084 spring steel, I had to go to elaborate means to get the job done without using a new drill bit for every third hole. I bought a mist coolant system and a special 2-flute, extremely hard, fifteen-dollar drill bit. The drill sharpener was supposed to save me from all this and allow me to sharpen my own drill bits, thus saving the entire purchase cost within a year, or about 25 knives, at that rate. Opening the box revealed a blue plastic contrivance with adjustable receptacles for different size drill bits. I followed the instructions and when I turned it on I was greeted by a shrieking noise that surely originated in the bowels of hell. No, that's the normal noise of the little diamond wheel spinning around at what must be 600,000 rpms. And when I pushed on the little receptacle to engage the drill point against the wheel the noise somehow managed to get even worse, as though hell were having problems with air in the pipes. I followed the directions and was mercifully allowed to turn off the drill sharpener when the sharpening process was complete.

The point of the drill bit was hideously disfigured and would no longer center itself in a hole, and was in fact useless for drilling in anything but wood or anything else soft that can be drilled using only friction.

It's pretty important to have a symmetrical drill point when trying to drill holes in steel. First of all, the drill bit has to be harder than the substance to be drilled if it is going to actually cut its way through the material. If an off-center 1/16th-inch drill bit manages to make anything like a hole in steel, the asymmetrical loading of the point will wedge one side of it into the side of the hole. Once there, driven by plenty of power from the drill press motor, it cheerfully snaps off in the hole, leaving a tiny shard of drill bit material protruding from the hole. The drill will sometimes manage to make enough headway into the steel so that when the bit breaks, the broken-off tip stays wedged tight in the now oddly shaped hole. Trying to remove it with pliers just breaks it off almost flush with the surface and leaves a little irregularly shaped piece of hardened steel which would grab and break even a new drill bit, right where I wanted there to be a hole. What I do now when my drill bits get dull is that I take the recalcitrant little bore over to my faithful variable-speed, adjustable table, vertical-disc grinder and hold it just so against the abrasive, and poof, a sharp drill. I'm not sure exactly when it happened, but I can now sharpen drill bits by hand, and then use them to drill deep holes in steel, which makes my off-hand grinding skills considerably better than the drill sharpener. And I'm a lot quieter about it too. I must admit that the manufacturer did cheerfully refund my money on the drill sharpener as advertised.

I still can't put my finger exactly on where the learning begins and ends with this avocation. It just seems to happen naturally and almost constantly. Even after ten years I still have knives and knifemaking on the brain. I do try to pay attention to other things in my life, but few things have the power to draw me so completely into their study. I have read everything I could find even remotely connected to the subject for the last ten years, and my interest in the subject has kept it all at a constant boil.