Stabby Kukri (work in progress, help appreciated)

[Jens Schuetz]

Hi,
I've seen a bunch of Kukris which had nice fighting blades but then they were to thin for real work, which feels like a waste to me. If I go into the woods (Appalachian Trail for example), then with only one blade, and maybe two very tiny ones
Some blades are too long for me and others too heavy. The normal working Kukri which I like the most is the 15 Inch Ang Khola from HI. Its length, weight and balance make it feel like that I could swing it for hours without blisters or fatigue. Its excellent for chopping and slicing and so thick that it will most likely never break. Its awesome for heavy and prolonged work. It will also do well in a fight were I get the opportunity and room to swing the knife and hit the opponent. But what if the guy or bear is already too close or I have limited space? There I would prefer a stabbing weapon, which needs no swinging and offers good penetration with less momentum. Spear point blades like on my 90s HK Bayonet from Eickhorn would do very well. Needless to say it couldn't chop any wood or limbs and is very bad at slicing too.
There were solutions to Kukris to make them more suited for stabbing. the HI Ultimate Fighter, Uncle Bill Especial and a few more. Some have a spine which is too sharp for batoning and all of their tips are pointed straight forward.
I prefer a slight downward angle which follows the Kukris curve and feels more ergonomic to me. It allows me to add my wrist movement to a forwards thrust of my arm thus flowing more smoothly and with greater power. Its like hitting somebody with an escrima stick with speed and control (can be pulled back very easily) It can also be described like the snapping of a whip which also adds arm and wrist movements together.
Is it possible to equip a working Kukri with a slight downward spear point tip without compromising its excellent balance and functionality?
I think I have found a way. I started from an 15 inch and ~18 ounce Ang Khola and came up with this.

The new tip is more pointed and sharp on both sides. The reduced amount of metal from a thinner tip should shift the balance towards the handle but is being compensated by the tips increased length. Even if its a bit longer it should still balance well like the Ang Khola, which I like the most.
The top swedge is not too long, which leaves enough spine for batoning. The spear point is still long enough to break through tough outer layers (thick cloths, skin, muscles). Once they are pierced the blade has to go through only soft tissue anyways. Also I left the top swedge at a length which is legal in my home country which considers anything with a second blade longer than 6cm a weapon. Being a "weapon" would severely limit the ability of carrying it. Private property would be ok, but survival training in a public forest not.
In addition to the enhanced tip I added a guard which prevents the user from sliding into the blade and could also stop an opponents blade from sliding down the blade, into the users hand. (Its a common technique in sword play and stick fighting where it hurts a lot even without any edges involved)
The tang is extended to form a so called "skull crusher". I angled it so that it doesn't mess up the users leg when missing a swing at a tree but can still be useful in a fight or against a mean coconut.

Does this all sound like to much change for a blade which has already been refined for many years?
First of all, I'm no Ghurka and surprising my enemies is impossible. If at all they will be surprising me, the victim. I might have no time for big swings or silently cutting throats in the night. For defense I need something which can thrust a bit better and work in small spaces.
Still, the changes are minor if you look at the second picture you can see 97% of the original Ang Khola within the new shape. Its really mostly a longer more pointy and sharper tip

The belly and sweetspot are unchanged and battoning is almost not compromised at all. I think the result is a Kukri which can still do heavy work and is at the same time better suited for defensive fighting situations.

From here on I plan to crunch some numbers and make more drawings before I make a mockup or two to confirm balance points on original and new blade as well as the change in penetration capability.


Please let me know what you think, where my thoughts might be off or what could be even better for my needs.
Thank you.

 

[-KJ-]

My mods are in blue. I moved the tip up a hair, but i don't know if that compromises your "pecking bird" stab. If you tried that with either mod I think you'd get a small cut with a gigantic knife ready to actually thrust. Both mods would do that quite well.

 

[ndoghouse]

Nice Jens! You would definitely be compromising a chopper by removing that much meat from behind the tip. Seems it would be vulnerable in camping situations where you might want to say pry bark off a tree or other lateral forces you get used to with an AK. I know i put lateral forces on the tip of mine probably even more than I realize but for camping i know I would bend that tip. Maybe using a more obtuse swedge and not extending it all the way to the other edge would give you a bit more meat to the tip and still give you the penetration you are looking for. Looks like a mean slasher and stabber in the works! The tang and guard is cool idea!

 

[Jens Schuetz]

KJ
Thanks for uploading your mods. Pictures really help a lot. Your version balances edge and swedge more. It looks very elegant. I will try both shapes to see what works best for me. "pecking bird" sounds fitting Thank you for your help.

Ndoghouse
Thank you. The tip isn't really the sweetspot according to this link we should chop more with the middle to back portion of the belly which is still supported by a full spine in this mod.
http://www.bladeforums.com/forums/showthread.php/720287-(WiP)-A-kukri-s-quot-working-edges-quot
You are 100% right about prying. That will be compromised. Adding a little ridge between the two edges and which becomes smaller towards the tip sounds like a great idea for more stability. Basically extending the curve at the back of the swede towards the front where it meets the other line. Will incorporate this tonight and upload it here.

Thank you guys, I like where this is going.

 

[-KJ-]

I'd also throw a second guard up top. Don't bother with anything fancy like a blade trap or basket hilt, but if you can block along the spine its another tool in the toolbox. EDIT: Top guard should be 90 degrees from the spine, not the hilt. That way blades don't just bounce off and mess up your forearm.

 

[Jens Schuetz]

Thanks again KJ
What shape would you suggest? A mirror of the bottom guard or something shorter? Will also look at my collection and the web.
Trapping blades isn't my style too especially with an 18oz wide bladed knife. A basket or trench knife guard feels quite safe but then changing my own hands position will be impossible. I think your double guard works best without compromising anything.

 

[-KJ-]

Go ahead and mirror the bottom guard length. A shorter top guard would compromise functionality and a longer one would just be weird. I think the only difference between your ideal fighting camp knife and mine is that yours is on a AK and mine is on a GS. Most wood you'll process in a long-term camping situation is going to be wrist sized and under, so the AK might be overkill.

 

[Jens Schuetz]

Thanks -KJ-
The GS looks great, no question. I admire the shape of the one made by Tirtha which was being offered here a few days back.http://www.bladeforums.com/forums/s...ix-Giant-Chitlangi-Bowie-Blems-and-Great-Buys I like it more than the one pictured at the HI homepage. The belly looks more pronounced and the tip more drawn out than on the stock picture. I don't like to say it because it might make me sound weak, but 18 inch and 20 Oz is a bit too much for me too handle fast and controlled. I only have 6 Kukris at home but I think it's enough to tell that the 15 inch/18oz AK hits my sweet spot.
After some stabbing tests with the CAK it turns out that an extended tip would hit higher than where I would have thought. Its almost exactly where you placed it in your mod. You have good eyes
I incorporated this, as well as the top guard and reinforcements to the tip.

I think its getting there and the general shape looks good.
One task left is to figure out how the groves of the original AK can transition into the new tip.

Is it possible at all or is it better to abolish the grooves. Is there any downside to having the cheek of the blade straight like on many other Kukris. What could be affected besides aesthetics?

Thank you.

 

[Steve Tall]

With an extended tang like that, wouldn't it need to be a CAK? In which case, it may be a challenge to get it down to 18 ounces (especially with the longer tang and guard and extended tip).

Balance will be affected, obviously, by the extended tang, especially if it's a CAK tang, so perhaps the extended tip shouldn't be thinned out too much.

My understanding is that the fullers and hollows/depressions give some strength advantages (similar to an I-beam) for a given weight.

 

[-KJ-]

IIRC for a given weight I-beams, fluted rifle barrels, and fullered blades have more rigidity. For a given size a solid bar is most rigid.

I wouldn't get rid of the fullers but I would see about possibly having the top fuller drawn into the swedge. I'm not sure how else to describe it, but if the fuller continues beyond its current point and then becomes the swedge it might look alright.

 

[Jens Schuetz]

With an extended tang like that, wouldn't it need to be a CAK? In which case, it may be a challenge to get it down to 18 ounces (especially with the longer tang and guard and extended tip).

Balance will be affected, obviously, by the extended tang, especially if it's a CAK tang, so perhaps the extended tip shouldn't be thinned out too much.

My understanding is that the fullers and hollows/depressions give some strength advantages (similar to an I-beam) for a given weight.

Thanks Steve Tall,
CAK was what I had planned. True, the extended tang gives it away. My AK I which I like the most is a CAK. I will weigh it to confirm if its 18 or higher.
My goal is to find the same balance point. To do this I wanted the general shape to be determined first (thanks for everybody's help) and then make some mockups. I thought I could calculate it but the shape is too complex, I might still try though by breaking it up into small segments and measuring their varying thickness plus approximating dimensions of the new parts. However that will take a while. Once we know where the balance point of the new design is we can go ahead and change how thin the tip is and make it a bit longer or shorter or add a bit more to the extended tang. But maybe I'm to quantitative and should let the Kamis decide. They know much better anyways. But then its also fun to get this done as much as possible and there is no hurry.


Thank you -KJ-
Fuller extending into swedge sounds like it can work. The fullers aren't that deep anyways and therefore should have potential to transition into a deeper swedge. Ill try to Photoshop this.


If the fullers add even more stability then lets keep them. They might also help reduce friction when cutting through soft and wet material. The ridges create some airspaces behind them during a fast cut and allow deeper cuts while a straight cheek has too much material clinging to it. Kind of like the effect of a cheese knife with profile cheeks.

 

[davidf99]

Jens:

I think your choice of 15" length and 18 oz weight is wise. However, a Gelbu Special would be a much closer starting point for your design than a CAK. It seems to me that what you are focused on with the CAK is the handle type and size/weight. However, if you plan to submit your design to the HI kamis as a special order, they can certainly make a modified Gelbu Special with your desired length, weight, handle type, skull-crusher butt and other design features. In the single most important feature, blade profile, the GS starts out closer to your design.

The Gelbu Special is already designed for both chopping and combat, whereas the CAK is mostly a dedicated chopper. Of course any chopper can be used or modified as a weapon, but why not start with a blade that is already multi-purpose? By the way, most 15" CAKs will weigh a lot more than 18 oz. It would be easier for the kamis to make a 15" 18 oz GS than a 15" 18 oz CAK.

I like the looks of your latest sketch, but I prefer the original hand guard. The problem with extending the guard above the spine is that it makes it impossible to hold your thumb on the spine, which is useful for finer work. You should ask yourself, is this a hiking/camping knife with good self-defense capabilities, or is it primarily a weapon and only secondarily a camping knife?

On a couple of other points:

1. If you're concerned about a bear attack, please be realistic and carry a small canister of bear spray. Or a weapon more effective than a 15" OAL blade. And make plenty of noise so you don't surprise a mother with her cubs.

2. Ghurkas had and have a reputation as fierce fighters under any and all conditions. I'm sure that Ghurkas would sometimes sneak up on an enemy and cut his throat, but in other respects they fought more like the Viking berserkers, and usually in military units. I wouldn't put them in the same category as ninjas, whose main reputation was as invisible assassins. I don't mean that as a criticism of the ninjas. They lived in a militarized society under the thumb of the samurai, and could only succeed through hit-and-run tactics.

I look forward to seeing the results of your design.

-- Dave

 

[-KJ-]

Good point on the top guard. For folks with hands over "Keebler Elf" size it might get in the way. I recommended it because I have plenty of room on the handle for my entire hand with the thumb up high and then some (most of the brass hilt). That said my "natural" grip seems to be thumb offset. It isn't curled up with my other fingers, but it doesn't ride the spine of the blade. I blame my 1911 for that.

EDIT: Just found my deluxe Woodman's Pal (D-guard with top guard). If you wrap your thumb around the top guard you get excellent control of the blade for fine whittling tasks. And you get good control by hooking your index finger around the bottom guard behind the edge as well. So a thumb on the spine isn't necessary when you've added a couple of levers to your handle.

 

[Jens Schuetz]

Thanks davidf99 and KJ,
very good points!
I use my thumb on folders occasionally but never tried to use a Kukri for finer work. For the guard we could use an oval. At the top it could have a cut out so that a thumb fits through. Ill make some drawing tonight or tomorrow. Another idea would be a top guard which can be screwed in or out.

The bear was more a just in case scenario. An encounter is very unlikely and wouldn't justify carrying a special weapon just for that. But if it still happens and they cant be scared away then a suited "multitool" is better than nothing.

The Ghurkas used their knifes in open fights and didn't having stabbing capability then because they didn't need it or had other weapons for that purpose. Maybe they haven't fought heavily armored opponents or they had other weapons for that purpose. Im just guessing. Would be interesting to know why.

So everybody prefers the Gelbu Special? Fine! I trust you guys that it can still chop fire wood for camping.
Ill try to find a straight-on picture of it and see how we get the tip on there.
I wish I would have one to experiment with. Until I get one I will just cut the shape out of some sheet metal to get a feeling for where the tip sits best. If all the other specs like weight and length, full tang and so on can be told the Kamis and they figure out how to balance it best then that would be amazing.

I like the Gelbu's description half way down this webpage http://www.himalayan-imports.com/Styles2.htm

Thanks again

 

[spiraltwista]

If the blade was given the new thinner longer point, with good distal taper, it wouldn't need the spine sharpened for stabbing, if razor sharp. Unused antique officer quality kukris often had points that you can pick splinters out with as there like a sharp needle.

Just my pennyworth.

Spiral

 

[-KJ-]

I like the idea of the cutout guard on top. As far as base blades go I'm wanting a perfect balance on all scales. If you need a chopper with good secondary fighting traits then stick with the CAK. The Gelbu is for if you want a fighter with good secondary chopping characteristics (my choice).

Ghurkas did use thrusts, but they were regarded as secondary to chopping. Probably because stabbing didn't remove arms legs and heads nearly fast enough in the heat of battle.

 

[Dirtbiker]

If the blade was given the new thinner longer point, with good distal taper, it wouldn't need the spine sharpened for stabbing, if razor sharp. Unused antique officer quality kukris often had points that you can pick splinters out with as there like a sharp needle.

Just my pennyworth.

Spiral

Agreed, I've got an unused M43 and the tip is indeed needle point sharp.

 

[ndoghouse]

Jens, You might try water displacement method for weight estimates if you have something like a tall graduated cylinder or container. Irregular surfaces are easy to estimate this way. Knowing the density of the steel (6150= 7.7-8.0 gm/cm3) and how much water is displaces would give you a good indication of how much volume each section displaces. Then you could calculate the weight based on each volume of water displaced by each section of blade. For example 7.7gms/cm3 X (volume water displaced in cm3(or cc))= weight of that section. Pull the knife out inch at a time and use a syringe or something of known volume and monitor how much water you added to bring water level up to original level for each inch. This will give you a pretty accurate idea of weight distribution. Just an idea. I used to use this method for determining specific gravity for rocks and minerals of irregular shapes to identify composition and is surprisingly accurate. Dont see why it wouldn't work for a chunk of smooth steel. Handle may complicate things but if you did this before with an AK you like then used it as a baseline reference while building the new knife you should be able to monitor the weight distribution as you fabricate.

 

[Gehazi]

for a stab blade I think i would go with a solid blade really, like the not very often mentioned malla , I would want a heavy stabber that would draw out easy

 

[Jens Schuetz]

If the blade was given the new thinner longer point, with good distal taper, it wouldn't need the spine sharpened for stabbing, if razor sharp. Unused antique officer quality kukris often had points that you can pick splinters out with as there like a sharp needle.

Just my pennyworth.

Spiral

Awesome Spiraltwista, and Dirtbiker
good to know that they had similar ideas back then and they were the professionals who actually used these weapons more often then us.
Distal Taper could be enough. Even if it requires a fraction of an ounce more push I think is not that much of a disadvantage.
Thank you.


-KJ- I experimented around a bit more and came up with this solution.

The grey middle circle is the handle under the guard and the triangle is the blade above it, so you can see the orientation and size.
The guard would be big enough to cover even my big fingers and my fat thumb would also fit in the hole. I'm sure its a size that fits everybody. (not like these "one size fits all" gloves, and hats) I used the hole of my bayonet and the thumb through there lets me not only control the blade in its cutting direction but also sideward. That's another advantage of having a top guard shaped like this. More protection and more control. Cool!
Also no matter how I move my wrist, with a guard of this size, there is no way I can make the guard touch my arm while holding the knife forward or reverse. I doesn't limit any movement.

Please let me know what you think and feel free to modify it. (everybody else too of course)

Nice that you know about them thrusting too, even if just secondary.
I like stabs. They need less space, less commitment than a full swing and are faster and more controllable. But true, a missing limb is more of a show stopper than a hole.


ndoghouse
That's an excellent idea. Water displacement!!! Thank you.
I used it once on some Chinese gold coins which seemed to thick. Turned out is was brass (gold plated). Ebay refunded me.
The handles average density (wood/metal) should be easy to find out. We just measure the knifes total weight and then subtract the calculated weight of just the blade (density is known and volume through water displacement). Then we measure the volume of the handle only and got its density.


Gehazi
The Malla looks pretty. What do you mean by solid blade? With flat cheeks instead of fullers?

edit: updated guard