Handles: Power vs. Speed

Well I've been watching this thread hoping it would die.:D

Not because it's not a good and interesting thread, but because I dont want to get involved. But, here I am.:confused:

I am not claiming to know it all about these knives. But, I have made several competition knives striving to get the most out of the size perameters. I think that if you go to extremes on any one design feature, you are going backwards. Too much handle drop, too much weight forward, etc.

Good design features done right and the technique to go along with it is what you want.

I'll check back and try to explain what I mean if you want me to. But it will be my opinion only and may not be the gospel.
Lin
 
Lin - I agree - striking a balance is key. Different makers will find that a different balance point (I don't mean that in the literal sense) works best for them.

I would certainly welcome your insight on this point.

Roger
 
Speed and power. What would you say If I said you can have both. To some degree.

I emphasize, to some degree. Because, I dont believe one knife can excell in both. It can have a nice balance of both and that is what I try to achieve. The rest is up to the cutter.

I ask myself where does power come from, besides your arm. Most would say weight. Where should the weight be concentrated? On the front part of the blade? I have thought that and made some knives with a lot of weight forward. They cut good, but not as good as I would have thought.

Weight forward usually has the side effect of drag. The drag counteracts the benefits of the weight forward. So, what if you were to put a moderate amout of thickness or weight somewhere else in the knife? Say the middle, ricasso, guard area. Would this give the knife power? I think it would. I do not believe the weight has to be forward for the knife to have power.

Now we have a knife with power without sacrificing slicing/cutting ability, because we can put a nice distal taper on the blade. This will help in the rope cut and things like that.

A knife that is 15 inches OAL still has a pivot, in my opinion. Control this pivot and you get speed.

Lin
 
In thinking about the original question, the only way I can get it to make sense (to me) is that they must have been referring to a fighting knife. The fact that a lot of the weight of a straight handled knife is more centralized in relation to the longitudinal axis of the knife than with a curved handle could be one reason it would feel quicker.

Another aspect (and I think the more relevant one) is in hand position and ergonomics. If you'll picture a straight handled knife in your hand held out in front of you in a typical saber grip and then compare that to a curved handle held in basically the same grip- wave them around a bit and you'll see that it is easier/quicker to change blade angles and direction with the straight grip. You can also see that a curved grip would give more power due to being able to push/pull on the the curved part of the handle.

This is all conjecture based on things I think I remember reading long ago. I think someone versed in swords would probably be able to help- think epee vs. rapier vs. sabre.
 
Hi Lin, is the pivot that you're referring to the wrist? Or somewhere along the length of the knife, like the hilt?
 
Lorien,
That's a good question and I will try to answer it from my view.

Someone mentioned before that some swords have a weight on the pommel to counter balance the blade's weight. The weight on the back of the sword brings the pivot back closer to the hand. With proper technique, the sword can develope much more speed. I'm not a sword person. It's just the way I think it works.

I'm not suggesting adding weight to the back, of course, but I am saying that on a one handed knife in cutting competition size or bowie size, I like to keep any extra weight in the middle of the knife. By being there, it does not hinder the speed of the blade. In my mind the speed is developed by combining the arm motion and the wrist snap. By having the pivot as close as possible to the index finger, the knife can snap. On a 10 inch blade, this takes some good forging/grinding, consideration of ricasso thickness, and handle material density.

In the competitions, the rules only apply to blade length, width, and OAL. This makes me wonder if there should be a range of weight. The maker would have to decide where he is going to concentrate the weight to the benefit of the knife's intended use.
Lin
 
lin,.....on your cutting comp knives are you saying that they have a distal taper to the middle....then get thicker and then taper again towards the tip?......ryan
 
Ryan - I don't know if Lin does it that way - but I have seen it done that way.

Roger
 
The thickest part of the blade is the Ricasso. From there it tapers to the tip. If it were a full tang knife, it would taper toward the butt too. This gets the weight in the middle of the knife. Near the index finger. The index finger and the pinkie finger along with the wrist, control the snap.

Again, this is just my opinion. Lin
 
Do you think that the design limits of the competition cutters is part of it. Mr Rhea mentioned a 'knife that is 15 inches OAL,' and 'on a 10 inch blade.' These are limits expressed in the rules, but there are also design considerations in the events. This limits useful blade profiles, so some handle shaping is in order, I would guess.
 
Any time limits are set on blade length, width, and OAL, makers have to put their thinkin caps on. :confused: The maker must consider all of the possible duties the knife may have to perform when considering weight distribution, angles, contour, texture, etc.

In the real world there are no limits, but for comparison purposes the limits give us a baseline. To me this is the only way to say for sure what design features are advantageous and what hinders.

The competitions have helped a lot of makers be better knifemakers.

Lin
 
Lin - a spin-off question arising from the limitation on dimensions.

If there were no such limitations, what do you think the dimensions of your ideal competition cutter would be? Put another way - how big does a knife get before the added size becomes a liability (within the context of the varied competition tasks)?

Roger
 
Roger,
I believe it depends on the intended use of the knife. I hate to be vague.
I believe no matter what OAL you make a knife you have to consider all of the factors discussed above tailoring the completed knife to it's intended duty. I do think the more VARIETY of duties you expect from a knife of a given size, the more the maker has to incorporate the proper design features and to a more exacting degree.

We had an interesting competition a bout a year ago in Old Washington. That year there were no limits on size or style of knife. Some had 11 inch blade, some 12, some had small swords. If I remember right the winner won with a 10 inch blade, of a style and design we would normally have used. Over all, it performed pretty well for all duties.
The longer blades did well on the gallon milk jug although some of the 10 inch blades were successful.
Lin
 
lwrhea said:
Roger,
I believe it depends on the intended use of the knife. I hate to be vague.
I believe no matter what OAL you make a knife you have to consider all of the factors discussed above tailoring the completed knife to it's intended duty. I do think the more VARIETY of duties you expect from a knife of a given size, the more the maker has to incorporate the proper design features and to a more exacting degree.

We had an interesting competition a bout a year ago in Old Washington. That year there were no limits on size or style of knife. Some had 11 inch blade, some 12, some had small swords. If I remember right the winner won with a 10 inch blade, of a style and design we would normally have used. Over all, it performed pretty well for all duties.
The longer blades did well on the gallon milk jug although some of the 10 inch blades were successful.
Lin
Click to expand...

Hi Lin,

Intended use in a cutting competition is what I had in mind, so your account of the open competition is most informative.

I have heard one maker opine that given absolute freedom to build a competition knife of any size, he probably wouldn't go much over 11" of blade length. This accords with my own personal preference in the bowie category for blades in the 10 - 12" range.

Roger
 
Lin-
Though we're straying from the handle topic, I always love discussing this stuff too. I'm curious to hear where the dynamic balance point ends up on your (or generalized) comp blades. I.E., the forward pivot point corresponding to the crossguard. Is it around 1/3 of the way back from the tip or so? Have you played with pommel weights to move it around? Or are the blades just too massive for a pommel to really do anything? Would like to handle a few comp blades someday. I thought we got Scott DeVanna interested in this some time ago, but I never heard whether he experimented with it or not; don't suppose he's ever mentioned anything to you about it? I'm just wondering if the mass distribution I prefer in my own big blades (for my own specialized purposes) is similar to what the comp guys like.

I feel the sword guys do have a lot of knowledge to offer on this topic. For those interested in the pivot points principles, see here: Sword Impacts & Motions
 
I know that the handle plays a part in power and speed. All of the work put in the blade and a handle that wont suit the purpose would be pointless. I guess I have a hard time seperating the two. In fact, when I forge a blade, I'm thinking of the handle too. That's how I know how to shape the tang.

I usually work from a sketch, so by the time I forge, I already have a pattern to go by. This takes so much guess work out of it, because as long as I refer to the sketch, I know what the results will be as far as how it will look.

I'm not sure where the dynamic balance point is. I suspect it is at least close to the actual balance point. In either case, I like mine as near the index finger as possible, considering the blade's length. Yes, I believe a butt cap would/could help on longer blades.

I'm working in my shop today. Lin
 
lwrhea said:
I'm not sure where the dynamic balance point is. I suspect it is at least close to the actual balance point. In either case, I like mine as near the index finger as possible, considering the blade's length. Yes, I believe a butt cap would/could help on longer blades.
Click to expand...

Wish I was working in the shop today. :)

I think we're talking about different things here. The pivot points are direct result of the moments of inertia, and there are infinite pairs of corresponding ones through the blade and handle. (which is why I find it easiest to just talk about one pair- the one at or just behind the guard and its corresponding point out on the blade) In practical terms none will lie exactly on the (static) balance point aka center of mass- they occur on either side of it. I make no attempt to move the center of mass to the index finger on my big blades; once you see what happens to the pivot points when this is done, it should become clear why.
 
I see what your saying about two opposing and corresponding points. Good point. It's a new thought to me. They would naturally apply only while the knife is in motion. That would explain your comment about 1/3 distance from the tip. I dont consider those points pivots, but I do see that they are critical points and I agree with you.

Even if I wanted to, I dont think I could move enough mass to the index finger to negate the dynamics of the other two points. That would be going to an extreme, which would in turn hinder performance somehow. I'm merely saying that if I want more weight/mass, I have to find a place to put it. To me, the ricasso is the logical place. Again, this applies only in moderation.

I do think that the handle's shape would enter greatly concerning the point you raise. To make full use of the dynamic pivots, the handle has to allow the full range of motion, while the hand keeps it's grip. That's another can of worms.

Lin
 
Lin,
Can i ask, your opinion about the "lopped off" tip style for these competition cutters, whether its experimental in nature, or do you think it has staying power?

..(woops, you already answered my balance question).
Thanks,
David
 
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