crazy persian

[sohail roshni]

Hi Guys
i was just doodling on my desk and came up with the knife design.
i call it the 'inverted persian'.
i like the design and feel the blade shape would facilitate in chopping things.
its a rough sketch.
would love to listen to your expert comments.

Thanks for your time.
-Sohail

[Lin Rhea]

Mr Roshni,
I am thinking the general shape of the blade resembles a recurve, with a little tweaking. I'm sure that it would be a good cutter for some application, although I dont have experience with this particular shape. I can imagine it cutting rope very well.
The only actual change that I would insist on were it mine is that the curve of the guard be reversed. Lin

[Lorien Arnold]

Sohail, please take this in the correct spirit, but this knife design is not practical for what you are talking about.
It is kind of cool looking and different, but if you are hoping that it will be a good chopping/bush use type knife, you will be disappointed. It is simply curved in the wrong direction.
I also feel that under torque, this design will twist easily in hand, making for dangerous and exciting times:eek:. Ask me how I know!

Now, if what you have designed here is meant to be a weapon, there is probably some merit to it, but I think it's probably a little too curvy for that. Most folk desire that the tip lie in line with the handle in order to avoid twisting. Finger grooves could be beneficial.

If this is meant to be an Art knife, then I think you are on the right track. It's different and interesting and depending on embellishment and finish it could be pretty cool and unique.

There you go, I hope that wasn't too harsh or mean:o

[Lin Rhea]

Mr Roshni,
I am in agreement with Lorien about the chopping. Now, IF the spine was thick and the blade a little longer, it would be sort of a cleaver. Any time a design reaches an "extreme" in shape, it's application always is specialized or, as Lorien says, an art knife. I recommend playing around with the drawing and lighten the angle of cutting edge to handle just a bit. Lin

[sohail roshni]

Most folk desire that the tip lie in line with the handle in order to avoid twisting.

first of all thanks for commenting on my design.i seriously thought that i wouldnt get any response.that happens on forums sometimes.
ok back to the design.
i am a keen learner and i seriously want to undertstand how to line up the tip with the handle.
i remember reading a post which had a picture of a knife drawing with a line drawn through the tip and meeting somewhere on the handle.
can you guys explain the technicality of having a good design.

thanks for helping.
-Sohail

[Kevin Jones]

Sohil, In my opinion a truly good knife designs is the result of an optimal balance of aesthetic and ergonomic properties while still being a little unique.

This may be the drawing you are referring to as it demonstrates various tip to handle angles for one of Lorien's designs. Both Lin and Lorien have given good critique of your design IMO. Thanks for sharing your drawing/design with us. I would like to see more maker and collector designs and drawings on this forum.

http://i142.photobucket.com/albums/r105/10456kaj/axelsonsketch1-1.jpg

[Lin Rhea]

Here is something that I try to always keep in mind.

From Wikipedia: Dynamics (physics), in physics, dynamics refers to time evolution of physical processes

A knife is a study in design and dynamics. We have all heard this in another way of saying it : form follows function.

The design has to allow for a range of movement by the user without detracting from it's function. A poorly designed knife will not allow the user full range of motion that is called for by the stated purpose of the knife.

In my opinion, the ricasso is the best baseline around which to design the whole knife. Lin

[sohail roshni]

Guys
i have seen the photo and that was the design i was referring to.
can someone explain the whole concept of drawing a line from the blade tip and how does it work?
from the figure it appears that the line must pass the tip of the guard and should meet the tip of the handle.

is there a writeup on this?

thanks
-Soh

[Lin Rhea]

As far as I know, this is the write up. :D

Seriously, I have not seen much on this subject. However, I think I know a little about it. I say this with a lot of reservation, because so much is based on opinion. My opinion, though, is based on what I have picked up in connection with the cutting competitions. I have had the privilege to hang out with some of the experts in cutting and knife design. Even so, I have never heard of anything resembling a formula by which to measure such things.
I have mentioned this before and am always a little "shy" about expressing my thoughts on angle and demensions, etc because, again, it's just my opinion.
But I use the ricasso as the baseline. Actually, the center of the ricasso. A line drawn parallel with and extending in both directions through the ricasso. From this line I can establish, relate, and repeat every other part of the knife, as far as up and down (North and South). East and West measure off the guard or bolster front.
There are some main points I want to be absolutely right. Once I get those, the rest of the knife will follow. For instance, Mr Roshni mentione the tips of the blade, the guard, and the handle. I dont worry so much about that untill a little later in the drawing process, and I AM talking drawing. By the time you are making the knife, all of the lines and points should have been worked out on paper.
The apex of curve where the index finger and the pinky finger sit naturally is one of my main concerns. If you draw a line through those two points, extending it through the main centerline, it will form an angle, if there is any handle drop at all. Naturally some knives wont have drop, daggers, some Sheffield styled knives, etc.
After I get those two lines, I draw my knife to fit it. Some knives dont need so much angle, some need alot. This is what I do and not to be confused with the proper way. Lin