Short survival machete ****Large pics****

F

Frank Lima

Joined
Jun 27, 2011
Messages
35
Hi I am brand new to this forum and am interested in making a short survival machete.
Here are pics of the CAD:
survival%20machete%20simple.jpg

and
survival%20machete%20simple%20drawing.JPG

all units are in inches. approximate weight 2.3 pounds made out of tool steel

~11" face will be the main blade
~3.25" face is a wedge
~4" face is an ax-ish blade
~6" face is intended to be a rip saw type pattern

Please let me know what yall think.
-Frank the Tank
 
It is unique, always like to see some out of the box thinking. Are you going to sharpen the gut hook for cutting rope and such? I would round the lower edge of the 4" ax-ish blade just so you dont break off that point. May make a better transition to the gut hook anyway. How are you going to transition the edge grind to the handle and the 3.25" face wedge? Also seems like there is not the need for the 3.25" width except to provide width for the wedge which may be questionable function give the thickness, You could save some weight by making a little slimmer. I had done a more traditional axe and had it waterjet cut looks like a good candidate, I use A2 tool steel.
 
woah, very technical.
how high up would the primary grinds go? My BK2 goes up pretty high to get that 1/4" thin enough to bother putting an edge on. Check out the BK3 for comparison, perhaps (think that's a chisel grind).
I imagine with a name like Frank the Tank you've got the muscles to swing that bad boy!

-Daizee
 
To be brutally honest that looks like carpal tunnel and a sprained wrist all in one. A handle like that will be nearly impossible to hold onto while chopping and even if you do, it's going to wreak havok on the hand and wrist. Not trying to be a dick, but often times something that may look cool on paper is totally unrealistic for real life (the beginning of the story of how engineers/architects and builders/fabricators grew to hate each other!!!). ;) :)

It isn't just the shape of the handle either... it's the way it's centered on a big, wide blade. It's going to cause a lot of funky, lateral deflection which is going to make it hard to use as well.

And while I'm on this train, I'll point out that I don't get big holes in the middle of a blade either.
 
This is the cad with the edges sharpened.
survival%20machete%201.jpg

and
survival%20machete%202.JPG


The holes are for weight reduction. Also how do you think I could improve the handle?

-Frank the Tank
 
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that is nice. some G10, i think, would be a necessity if that was going to be at all comfortable to swing, but it is really awesome as is. there are a couple things. 1. i think the guthook is basically unnecessary becuase you have the rip saw. anything that the gut hook excels at is also adequately covered by the rip saw, and the latter is generally more versatile. 2. the holes in the blade are going to make those parts that they are in more vulnerable to breaking if this is going to be a pretty hard heat treat. 3. I think removing some of those small points on the 4 corners could be helpful becuase that would, among other things, probably be the first thing to break. 4. what is the different going to be between the axeish blade and the main blade? is the grind on the 4 inch section going to be steeper? 5. I assume that you are going for something like D2 or L6 on this blade, right? some 3v would be very nice, though. those are basically the only steels that i can think of that would be tough enough to stand up to this kind of abuse.

Edit: I just saw your second post. frankly, this thing is already super heavy, and so the extra weight might not make that much of a difference. also, the tip of that gut hook is going to get snapped off the first time that you miss a swing and it takes the full brunt of the blow.

all of this is my opinion, and i am just going off what i have seen. welcome to the forum.
 
This is the stress analysis with 5000 Newtons (1125ish pounds) on the ax-ish blade:
stress%20test.png

No red no problem.

I intend to use A2 steel, is this a good idea?
The main point of the hook is to help with climbing trees and such. Other than rounding out the handle what do yall think of angle/length/width of the handle?
-Frank the Tank
 
what program did you design that with and is it hard to use ? I wanna prototype some idea's and my drawing is worse then my knife making skills
 
I use SolidWorks. It is extremely user friendly (for CAD software) but its not cheap. I have a student copy through my school but a regular licence costs in the thousands. Granted bit-torrent is free. If you do get it make sure to do all the tutorials they get you up to speed in no time.

Another good option is sketchup, it is free and ez to use but it does not have FEA (Finite element analysis). FEA is the blue to red gradient thing that gives you an idea of the durability/breaking points of your knife/part.

-Frank the Tank
 
Nice, but i been in the woods alot and can't see the spike on back really helping anything, the tree climbing idea is interesting though, i would also round ALL those sharp edges everywhere, if by handle will dig in hand if on blade will chip off with impact swings, chisel ground tool steel those sharp tips are toast if not sunk in soft wood, i'd make one just like you got on fancy drawing then take it out for weekend and wreak havoc with it then change whatever bugged you about it...
 
With all due respect, I think you're trying to put way too much into one ungainly package. I'm not entirely sure what you want the blade to do well... "trying to drink whiskey from a bottle of wine" comes to mind.

I agree with Nick about the handle/leverage etc, it's an injury just waiting to happen.

You want to design a survival machete? Take a long hard look at inexpensive goloks, parangs, kukris and, well, machetes. Spend $150 or so and buy one of each, and beat the living snot out of them in the woods somewhere. Your design parameters will become much clearer.
 
OK, Issues by the number:
1) The handle is at an angle to the blade - make it in line or your wrist/hand will suffer.
2) CLIMBING TREES????? Are you kidding me? - The last thing you want in your hand when climbing a tree is a sharp object with hooks on it.
3) The holes may look cool, but will do little to lighten the blade, and much to break it.In a chopping tool, mass is your friend....harmonics is your enemy.
4) The point on the "axe" face will be gone in two chops - square it like the front corners.( or get rid of it all together)
5) The pointed guard tits are weird - make them rounded back or squared off....or something besides pointed ( unless killing Zombies is a desired function).
6) The "axe" face? With 11" of sharp chopping edge, why will you need 4" more on the other side. Just put the vine/rope cutter on the end and have the saw back run down to it, if you really want the cutter.
7) The hook - While it looks cool, it is a feature that will see little or no use, and be hard to maintain. Leaving it off and having the saw back end in 4" of flat spine will allow battonning of the machete, as well as hammering of objects..
8) The handle - I would make the handle an inch longer and the blade an inch shorter. The ratio will be much better as far as impact to the wrist and hand....and what you can cut/chop wit 11" can probably be done with 10".
 
Hope this is taken in the spirit given.

Frank, in your analysis concentrate the stress on the point of your hook and see what happens. ;-). And as Stacy stated, harmonics will get you.

Few other observations: .25" saw is beyond useless. Have you ever seen or used a hand saw thicker than .1" (most are half that)? If you have no set to the teeth it will bind when sawing. If you add set to the teeth it will bind when splitting with the edge. The blade holes, besides weakening the blade, will also bind in the wood.

If you are looking for tacticool you have it, it looks neat. But as an outdoorsman I would never choose this design. As others have stated - look at the tools of blade centric culture and see what works best in various environs.

Best,
Steve
 
Im happy to see this post!!! Solidworks contacted me about a local demo etc..etc,, the sales man try to sell me on the defencies of me not knowing certain thresholds...newton forces..etc..on my own designs, i was polite and said i made hand made knives and that the local big guys gerber, kerhaw, would be interested!! Frank cut that dude out on some plywood, real time, youcan widdle the design down litterally and then run it through the computers to manage the build in steel???
 
I have only one question... is this something you actually intend to use, or will this be a wall hanger? If it's a wall hanger, follow your muse. If you intend to really try to use it, you'd do well to read with an open mind the critiques that have been offered.

Nothing wrong with making fantasy blades, if that's your thing. Not so wise, though, to try and take a fantasy blade into a working situation. I'd never go into a knife fight with any of the funky blades I make. :)

- Greg
 
GTH11,
SolidWorks is a bit of an over kill for a project like this, and non-mass produced knifes in general, but I like it. It helps me get my ideas in order. I also tend to print 1:1 drawing of what i design and just rubber cement it to the metal. That really helps speed up the build as i don't have to measure much

Also thanks for all the constructive criticism. I build robots not knifes so this is all new to me, thanks for all the comments. As far as the hook after thinking about what yall said I agree that the design can do without it. On the handle yall made some great points about blade control, but I don't really want to do a traditional blade. As far as the speed holes on the design^ they cut about .6 pounds (theoretically) off the weight so I think they are justified.

So I drew this up really quick I will probably CAD it up soon.
2011-06-28_09-42-00_650.jpg


On a side note this is probably the most active helpful and considerately constructive forum I have ever been on. I ask because I want know how I can be better not because I want a pat on the back (i have my teddy bear for that ;) ) so keep the constructive criticism coming.

-Frank the Tank

Edit: Yes i intend to use this blade.
 
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Frank Lima said:
On a side note this is probably the most active helpful and considerately constructive forum I have ever been on. I ask because I want know how I can be better not because I want a pat on the back (i have my teddy bear for that ;) ) so keep the constructive criticism coming.

-Frank the Tank
Click to expand...

I applaud your creativity and your thoughtful attitude. :thumbup:
 
Frank, do you mind me asking what kind of robots? I like me some robots ;-) In a previous life I worked for/with Accu-Fab, Eco-Sno, Logical, Adept, etc.

Back to blades. Thoughts if you want the blade lighter you can: raise the grind height, reduce stock thickness, use distal taper, add a fuller.

On your second design the ergos are 180° off for using the saw. Do the plywood template as suggested for a quick test drive.
 
Frank, you said that the holes were justified because they saved so much weight (.6 lbs. I think). On this style of knife I think you want weight. It would be the equivalent of drilling holes in a sledge hammer to make it lighter. Sometimes light is good, but in this case I think light is bad, not to mention the vibration issues it may cause.
 
I the only project of note is a humanoid robot ( http://www.me.utexas.edu/~hcrl/ ) project.

Here are some pics of a card board prototype.
2011-06-28_14-19-05_757.jpg


I only have 2 hands but you can get a pretty positive grip on the saw if you put one your thumb through the front loop and the other hand on the handle.
2011-06-28_14-18-45_843.jpg


-Frank the Tank
 
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