M.A.C.K.: What Are Machine Assisted Custom Knives?

M.A.C.K.: What Are Machine Assisted Custom Knives?
The Orochi folding knife by Princeton Wong is a complex task for both the machinist and the knifemaker. All these parts don’t program themselves to proper dimensions, and they don’t come finished, either.

Learn what the latest BLADE Show custom knife award is all about.

Some people are familiar with “Mack Daddy,” the 1992 Sir Mix-a-lot album with the smash hit “Baby Got Back.” On the other end of the cultural spectrum is the Mack truck, the reliable American long-haul vehicle revered by truckers and country songs. Knife enthusiasts may also be familiar with the Bobby Darin’s classic Mack the Knife: “O the shark, babe, has such teeth, dear …” Just now coming into the knife culture is the idea of a “M.A.C.K” knife, which stands for “machine assisted custom knife.”

Custom, Production And M.A.CKnives

Savvy BLADE® readers know the difference between a “custom” and a “production” knife. A custom knife is made by a craftsman using a combination of skill, experience and tools. The maker grinds the blade, polishes it, installs a handle and fittings, and so forth. Custom knives are often made one at a time or in small batches. Sometimes portions of the process are outsourced, such as waterjetting blade profiles or using a professional heat treater. In general, the maker’s name is prominently featured on the blade, such as Tom Overeynder, Gary Langley, etc. The price of custom knives can be quite high, particularly as the complexity of the knife and the magnitude of the maker’s reputation increases.

By contrast, a production knife is made in bulk using modern or traditional manufacturing techniques. Blades are made by the hundreds or thousands, ground and polished by machines, and assembled in a factory or large production shop. In general, the name of the company is prominently featured, like Case, Benchmade, White River Knife & Tool, etc. Sometimes a production knife will feature the name of the designer, such as the various CRKT production knives that have BLADE Magazine Cutlery Hall-Of-Fame® member Ken Onion’s name. Production knives may be expensive but are generally more affordable than custom knives of similar materials and construction.

Princteon Wong award-winning knife
Princeton Wong has a five-axis waterjet in his machine shop, so he makes everything but the screws. An example of his work is this award-winning knife from the 2021 International Custom Cutlery Exposition, now known as BLADE Show Texas. (Caleb Royer image)

In between custom and production is a vast world described by the umbrella term mid-tech. It describes knives that use both production and custom techniques or methods in varying proportions. Some would say that any knife that has production techniques like waterjet is a mid-tech, while others would argue that as long as a person does the final assembly and fit up, a knife can be called a custom.

It takes talent, practice, education and skill to make a knife by hand. Many makers of such knives have no problem with using machines like a band saw, 2×72 belt grinder, manual mill or pantograph. At some level, almost every modern handmade, aka custom, knife is “machine assisted.” At the same time, the industry recognizes that when it’s primarily the maker’s dexterity and artistic vision that makes the knife, the label of custom or even “handmade” applies.

It also takes talent, practice, education and skill to program a series of CNC (Computer Numerically Controlled) waterjets, grinders and mills to make a knife by machine. Custom guys often make “polished turds” and “boat anchors” at the beginning. Beginner machine guys break tooling and crash expensive machines. In neither case does a person wake up one Tuesday and immediately become a competent knifemaker.

Think about the amount of variability in custom/handmade knifemaking. Each steel, each belt, each grinder speed, each brand of sandpaper, and every variable changes the process. If you heat treat your own steel, you must master temperature control, soak time, quench speed, decarb, warpage and tempering, and must use a different formula for each steel. After dealing with all that, is making a knife by machine any easier?

Princeton Wong operates the CNC mill. It can cut complex 3D
Princeton Wong operates the CNC mill. It can cut complex 3D shapes in metal and handle material.

Not according to M.A.C.K. knifemaker Princeton Wong. In CNC you deal with the geometry and composition of various cutting tools, plus the speeds and feeds at which you apply them. You must figure out fixturing to hold your workpiece, and how to work the tool in a way that leaves the desired surface finish. “It’s the same idea as using different belts or different files for each task,” Princeton explains, “but the variables are infinitely more complex. And then on top of that, you still have to learn and master all of the different hand-finishing techniques.”

So how does the knife industry show respect to the skills and talent of the makers who artfully combine programming with handwork? How do you showcase the ability of a maker who can run both a HAAS CNC mill and a belt grinder?

Defining M.A.C.K. Knives

BLADE Show 2023 included for the first time an award category for M.A.C.K. knives. According to the category rules:

The knife must be of the folding/locking, non-slip-joint, EDC variety that is first and foremost a cutting tool. It must be functional, beautiful and have great ergonomics, yet still have practical applications and uses. It must consist of both at least one handmade feature—such as hand-ground blades, hand-contoured scales, manually machined parts, etc.—and of automated features such as waterjet-cut liners/scales, CNC’d handles, etc. The judges will assume that the knife’s parts that are not handmade are made through a machine-aided process.

What background education and experience does it take to make a quality M.A.C.K. knife? Just like with any other skill set, the path is quite diverse. Take Princeton for example. Knifemaking for him growing up was a passion.

“As an Asian kid into martial arts, I’ve always had a love for bladed implements,” he notes.

A waterjet machine uses a high-pressure stream of water and abrasives to cut profiles in flat stock.
A waterjet machine uses a high-pressure stream of water and abrasives to cut profiles in flat stock. Princeton Wong uses his waterjet here to cut Timascus™ for folder handles.

He bought a Sherline mill after high school that had been converted to CNC, and learned by trial and error from there.

“After years of fiddling with stuff, breaking endmills and crappy software, I finally started figuring it out,” he observes. But for Princeton, learning wasn’t all trial and error. He studied mechanical engineering and graphic design in college. He had jobs in print, web, graphics and fabrication. Eventually, he started his own machine shop serving automotive and architectural clients. In 2018 he decided to use his machining skills to make knives.

“I didn’t know the knife industry or knife people but had a machine shop, so I gave it a shot,” he recalls. “I didn’t own a ‘real’ belt grinder until I was two years into making knives. I had a 4×36 from Lowe’s but was able to do very close work on the CNCs. By focusing on an intentionally machined look, I was able to get by.”

Princeton has a five-axis waterjet in his machine shop, so he makes “everything but the screws.” Earlier in his progress, he would bandsaw blanks and then fixture them in his CNC mill.

“I never had a need to outsource, but most people don’t have 70 amps of 480-volt three-phase electricity to run a $100,000 waterjet,” he says.

A waterjet cuts steel and other plates into shapes, “but it doesn’t make knives.” It’s a highly efficient profile-cutting tool.

Bridging The Gap Between Custom And Production

Most people don’t take Wong’s path and start out as fully equipped and capable machinists when they begin making knives.

Consider the precise fitting and complex geometry of the joints on Jared Oeser’s “Tachi” folder.
Consider the precise fitting and complex geometry of the joints on Jared Oeser’s “Tachi” folder. Integral bolsters and Westinghouse Micarta® come together quite well.

M.A.C.K. knifemaker Jared Oeser started like many makers, with a mentor, a few tools and a new hobby. As a homebuilder, his business took a hit in the 2011 recession. Faced with spare time, he took up knifemaking. After a few fixed blades he moved fairly quickly into slip joints, merging modern materials into traditional designs at a time when that was a new thing. He continues to push the limits and bridge the gap between traditional designs and the “modern” folding knives.

About five years ago a friend needed a place to store a CNC mill. Oeser agreed to store it in exchange for lessons and use of the machine in the meantime. By the time the friend needed the machine back Oeser was hooked and bought his machine shortly thereafter.

After five years, he considers himself not good enough to make a knife completely on the machine. Coding for CNC is quite a different skill set, far beyond traditional knifemaking.

“I don’t want to go 100 percent machine,” Jared says. “I like the hand work, and I’ve gone about as far as I want toward machine-made. Everybody kind of finds their ‘spot,’ but the key is to disclose it, to say it. Don’t say ‘mine’s handmade’ if you’re afraid to say how you did it. At the end of the day, you’ve got to be good at hand work and have a skill set to make a quality knife.”

Handmade Vs Machine Assisted Knives

So what’s the difference between a “custom/handmade” and a “machine assisted” knife?

Wong suggested that a machine assisted knife should have a bit more precision than the typical custom knife. Because you can machine to exact tolerances and fit, there’s less room for error. He also suggested that the maker should try to push the boundaries of the machine’s capabilities. Just like there are a few knifemaking operations that can only be done by hand, such as Wolfgang Loerchner’s amazing hand-filed creations, there are also machinable features that people wouldn’t realistically try by hand. Creativity isn’t limited to hand tools.

Jared Oeser’s “Eagle” is a four-blade slip joint
Jared Oeser’s “Eagle” is a four-blade slip joint. This one has mammoth ivory handles and a 14k-gold shield, combining modern techniques with traditional materials.

According to Oeser, “Among the makers and collectors I know, we’re OK with whatever a knife is, as long as you honestly disclose how you built the knife.”

He considers his knives machine assisted. On a slip joint, he uses a HAAS CNC mill to cut out the shapes of the liners, the shield inlay pocket, and to profile the blade and spring. Even though he uses a CNC mill that is squarely in the “machine assisted” category, using it primarily to cut profiles is pretty much the same thing as a waterjet.

Taking The Plunge Into M.A.C.K.

As a mostly one-off knifemaker myself, I was curious what it takes to build a knife that falls squarely into the M.A.C.K. category.

After talking with some M.A.C.K. makers, I found the process seems to typically begin with waterjet cutting. Either the maker has used a waterjet before and has his or her own CAD (Computer Aided Design) files, or the contracted machine shop will have a CAD expert on staff. Experienced CAD folks can work from a drawing or PDF for things as simple as profiles, and may use modeling software for contours and handles.

Princeton Wong checks the tooling on a CNC lathe.
Princeton Wong checks the tooling on a CNC lathe. The lathe cuts precise round stock, such as screws and folder pivots.

Typically the liners are cut and the holes spotted, or are occasionally fully drilled and tapped. Pocket clips and backspacers come pre-cut. Handle profiles and contours are cut with a ball end mill, leaving a fairly clean finish. Sometimes this finish by itself is sufficient, while other times more hand polishing is necessary to achieve the final effect. Blades are typically delivered cut to contour, and the maker often does the bevel grinding by jig or by hand on a traditional belt grinder. Other times the blades come with machined bevels at varying degrees of surface finish. Once again, it’s up to the maker to decide if the machined finish is sufficient or if further hand work is necessary.

If you’ve ever used waterjet or milled parts, you know that the edge finishes are not precise. If you’ve had holes spotted but not drilled, you still have to drill and tap the holes. All in all, even in a knife that comes to you in a bag from a machine shop, there’s more to a cleanly finished M.A.C.K. knife than just assembly. If you want to be a winner in the M.A.C.K. category, you’ve got to have the hand finishing techniques down pat.

If you want a firsthand look at a quality M.A.C.K. knife, check out the applicable tables at a BLADE Show. Whether you prefer the events in Atlanta, Texas or Utah, there’s no doubt that “M.A.C.K. is back in town.”

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