On the Engineering of Swords...

We all love swords.

Shiny, slicy, stabby, sharpened (or unsharpened, as you prefer) pieces of steel are just our favorite things in the world.

However, for all of our love and adoration, there are many of us (myself included) who don't possess a firm understanding of the complex engineering (and there is a lot, rest assured) that goes into carefully crafting, and handling what ultimately comes down to (oversimplifying in the extreme) a long, thin piece of metal with a handle so someone can swing it.

But, among the many sword enthusiasts, smiths, HEMA practicioners, and others on Facebook's All Swords group, and throughout our steely microcosm, there is one man who has decided to shed some light on the things we reference so often when chatting about the various and proper qualities of a well-made, functional sword.

That man is Collin Miller of Miller Forge.

Stay A While & Listen...

"It's come to my attention that the handling of swords is something that isn't understood in any measurable way by what I would consider a significant percentage of the group. That's okay, I'm here to help try to educate, not start arguments.

Peter Johnsson has a different perspective than Gus Trim. These guys don't have the same approach, but they make some of the best-handing swords out there.

Now, I am qualified to talk about this, but this is MY perspective.  

Tobias Capwell once said, "A good sword should be light in the right ways, and heavy in the right ways."

That pretty well sums it up in a sentence. But in what ways should it be heavy? In what ways should it be light? How do you recognize this or measure it?

To explain that, there are some very basic principles I'm going to help you understand:

Sword Inertia
The first and one of the most important (in my opinion) is the principle of inertia. More specifically, the acceleration of mass.

I'll go ahead and let the cat out of the bag: I am NOT a physicist. I have no formal education in physics, and I can barely spell the word physicist. But I do have experience in how physics relates to swords.

To explain this, Peter Johnsson uses what I believe is called the "Dumbbell analogy:"

If you have a round piece of steel shaped like a dumbbell, and another piece of steel with the same weight and length, but is thickest in the center and tapered on both ends, which one takes more force to accelerate to a spin?

You guessed it, the dumbbell. This is because of inertia.

You have to set more mass into motion because of its shape. However, it will also take more force to stop spinning, because there is more mass.

This is one of the reasons we have distal taper. It is also the paradox of a sword being heavy in the right ways and light in the right ways.

Weight, Mass & Leverage
A sword with more mass in the tip will be less agile and require more energy to set into motion, but it will also hit harder because there is more mass set into motion. 

A good sword will balance these properties for its intended task so that the sword is easy to set into motion and hits hard enough to deliver a powerful attack.

What I just explained also has to do with leverage. Picking up a ten pound weight is easy, but picking up a ten pound weight on the end of a stick is less so.

Vibration Nodes, Pivot Points & The Pommels That Love Them
Now we will move onto pivot points and vibration nodes, and how a pommel tunes these. These are the terms I learned, so they're the ones I'll use in this post/article.

It was brought up in a recent post (on All Swords) that it is easy to cheat your way to what is considered a "good" point of balance by putting a big ass pommel on a clunky blade.

This is true, and a pommel is NOT to act as a counterweight and its primary function is not to change the point of balance (the pommel does change the POB, but that just is more collateral damage, not it's main function).   

The more weight you affix to the ass end of your blade, the farther away the pivot points in the blade get from the hand, and the closer they move to the tip. The vibration nodes get closer to the pommel end, with the hilt node usually resting somewhere in where you would place your hand on a grip. 

As a a general rule, the hilt node on a two-handed sword tends to feel best around where the heel and pinky finger of the front hand rest.

On a single-handed sword, it should usually be just behind the guard, where your index finger and thumb wrap around.

That is over-simplified, though.

What you really want is for your pivot points and vibration nodes to talk to each other and work in harmony. 

If you have a really well-balanced sword in your collection, you might test this for yourself.

The Test
Pinch with your finger and thumb the node in the grip and let the blade hang down. Now, smack the pommel.

Get your finger and thumb situated right in the middle of that hilt node. On the blade, you'll see a corresponding node somewhere hopefully near the 2/3 point in your blade. This is often called the COP or "center of percussion" (this varies greatly depending on the intended use of the sword).

Now with the sword vibrating, and you gently pinching the hilt node, waggle the hilt straight side to side, somewhat quickly (it takes a good bit of practice to get accurate and consistent results with this measurement).

When you waggle the hilt horizontally, you should be able to see something of a fulcrum point, where it looks like there is a nail through the blade that it is pivoting on.

On every well balanced sword I've handled, and on most originals I've seen measurements of, the vibration nodes and the pivot points that correspond with the location of these pivot points is very close. Often, they are sitting right on top of each other.

So when your blade has good mass distribution, you can adjust the pommel weight until these points correspond. Pivot points go forward and vibration nodes go backwards. There is a sweet spot or Goldilocks range (yes, it is a range) where they talk to each other.

The Importance of Mass Distribution
The mass distribution of the blade is what really determines how the sword feels. You cannot, I repeat cannot, make a blade with bad mass distribution handle well with a different pommel.

This is because the point of balance is not what makes a sword feel the way it feels, and the pommel is not a counterweight. The pommel is a device to fine tune the handling of the blade.

Too heavy of a pommel, and the sword feels weightless and dead. Too light, and the blade will feel sluggish and unresponsive."

About Collin Miller
What this young smith may lack in winters, he more than makes up for with fiery, hands-on experience at the forge. Creating various types of European blades (knives, swords, axes, and more) with mythological, and legendary influences, Collin is almost completely self-taught and always evolving in his capabilities.

Collin crafts his metallic creations at his home shop, Miller Forge, and can be seen doing what he does best on his YouTube Channel: