Making a knife exactly like a drawing?

Patrice Lemée

Patrice Lemée

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Aug 13, 2002
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In another post I read about CAD programs not making natural curves and CURBS whatever that is. I never had a problem with it since the drawing is just a basic layout for me. The shape is "tweaked" as I build the knife.

How many of you guys make a knife exactly like the drawing?
 
I typically hand draw, but will copy and glue the drawing onto a piece of 1/8 micarta for a model and that will be exact. I then modify the micarta as needed for the first model, I may have to glue on more micarta to make the modifications. I use that to make a second model which does not have any glued on pieces, and then go to steel.
 
I usually trace the outline I want on the blade, and profile that, but I will almost always make some changes. I can grind out a smooth curve better than I can draw it.
 
Patrice Lemée;8373607 said:
In another post I read about CAD programs not making natural curves and CURBS whatever that is. I never had a problem with it since the drawing is just a basic layout for me. The shape is "tweaked" as I build the knife.

How many of you guys make a knife exactly like the drawing?
Click to expand...

Its NURBS not CURBS:p and what I do on the computer is never exactly like what comes out in the end. I use the computer to draw because it is much easier to modify my design in a digital format then with a pencil and paper, I would go through about 20 erasers a drawing:eek:.

I draw and tweak on the computer till it is visually appealing to me, then print it up on card stock trace it out on to the steel and go from there. I modify as I go to get it feeling just right in my hand, so the end product resembles the original, but isn't an exact reproduction.

The software I use also allows me to export into a format that a CNC machine could read so if I ever find a big bag of money I am all set and can go from computer to CNC for things that need to be exact, like folder parts.
 
For me a drawing is only a concept. Several times over my knifemaking career I have had people send me drawings and tell me that they "want it EXACTLY like the drawing", and have even had a couple of people send actual blueprints... and I generally tell them that I won't build the knife for them.
On one of the blueprints I received, the individual had even specified blade thickness at 1/2" intervals, in thousandths of an inch, over the entire length of the blade....when I spoke with him I told him that he needed a precision machinist, not a knifemaker.

It's not that I can't build a knife from a drawing, but from experience I know that many of the "features" that folks draw into their "dream knife" are things they simply will not like once the knife is in their hands. I always tell folks that drawings are welcome, but the caveats are that they are only for reference, and I reserve the right to modify aspects of the drawing in order to "improve" the function/form of the knife.
 
People are bad about drawing grind lines that don't make any geometric sense. They don't have a head for geometry. A common error is a grind line that goes directly to the tip, which would create a point like a screwdriver on the end. I keep seeing people draw things like this.

Pat,

I'm the one who said that CAD is generally a lousy tool to design a knife in. Most CAD programs you guys are going to play with want to draw true arcs. If you look at something with a nice flowing shape, there aren't going to be many true arcs on it. It might have a sweeping line that at one end has a 100"R, a 50R in the middle and a 1" R at the other end, with every other radius in between those in an infinitely varying arc. Look at a French curve for an example of what I'm getting at.

french_curve.jpg


Practically all aesthetic products are designed with non-linear geometry. Cars, consumer products, everything. Artists draw this way, and high end design programs generate this kind of geometry with different types of spline geometry. Parabolas and conics would be simple examples.

If you're going to go to the effort of making a hand built custom knife, the shape should be important to you. If you hope to avoid a clunky shape you should avoid letting the CAD system "drive". This is a common problem that I see a lot.

I would suggest doing your knife design in a drawing program like adobe illustrator or similar that supports smooth clean curves.


For what it is worth, I use CAD a lot. I use it do design plastic parts for injection molding and I do quite a bit of it. Examples:

http://s566.photobucket.com/albums/ss107/Nathan_the_Machinist/product_designs/

These are not highly stylized consumer products, and even they don't use many straight lines and true arcs like someone just piddling with CAD is prone to do.


...my .02...
 
I tend to draw for about an hour then after a lot of erasing I may have a design I like or a crumpled ball of paper. I cut out the design and trace it on cardboard, usually from cereal boxes, and transfer that to the steel. Of course by that time, it seems to be a little bigger than I started with hehe. Normally by the time I have finished grinding the steel it is about 10% bigger than the original. I really need to start drawing smaller first.
 
I draw mine first on paper and then scan it and sketch it out in Adobe Illustrator. Sometimes I skip the paper part and just draw it on the computer.

I'll add shading and render a pretty complete knife before I make my paper template. The paper template helps me get the overall shape and hole alignment so that I can repeat the design if needed.

They are not exact but close enough for me. I kind of like the fact that each knife is a little different, even though I used the same template for each.

Here's an example of a drawing and the finished piece.

Adobe Illustrator drawing
Thaichopper.jpg


Final pic
pokechoppa-01.jpg
 
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Correct me if I am wrong Nathan but that's probably why it works for me in CAD. Almost all arcs I draw is made up of a few different "sub-arcs" of different radius. Not sure if I explain myself correctly here. I will try some paint program again though. I did in the past but never liked it much. Maybe I just did not give it enough time.

From what I see most people use the drawing as a start and go from there like I do.

Thanks for all your feedback.
 
I've a lot experience in design.
I.ve used to use Illustrator for some rough ideas. But later all theideas will come flow in severl environemnts and so i taake sketches, paers in my pocket, written cigarettes box...

But what I find most to make me happy is making some templates with MDF ot some thick plywood designed by freehand.
Eventually I use some other hand tools, as curves.
And most of time I will modify the design on the way, maybe because there are something to adjust such as for example the balancing or the feeling in my hand...

I'm very precise but i feel also confortable to follow my instinct and my ergonomy.
Cheers
 
Just a beginner here but Grand Leavitt has ground several blades for me with submitted drawings and I ALWAYS state as Ed did that he is free to change whatever he feels needs to be changed no questions asked. He is the knife maker I just give him my ideas and go with it. I have always been very pleased with what he has done with my ideas. Just my 2 cents:)
 
CAD can make exactly the curves you want. It's just a matter of experience and practice. ;)
This said, I usually forge the steel, try to suggest a form, look what the steel "wants to do", correct it if I don't like it or follow it if I like it. A couple of the knives I made that I'm more satisfied with were made just refinining the shape the steel took almost spontaneously.
I tried knives following a design, but never "blueprinted" them.
To exactly follow a design, I'd have to work mostly by stock removal, while I like forging. I like to bring the knife as close to finished as I can just by forging, but I'm not so skilled that I can follow exactly a project.
 
Patrice Lemée;8375687 said:
Correct me if I am wrong Nathan but that's probably why it works for me in CAD. Almost all arcs I draw is made up of a few different "sub-arcs" of different radius.


... uh yeah... I don't think you quite get what I'm getting at. But that's okay. :thumbup: It is just my opinion.:)
Click to expand...
 
I hand draw my concept designs.... If I can draw it.... I can make it. Like Ed says, they are just guides. My knives are simple enough that they don't vary much from the original drawing.


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I started drawing knive a while back, sent one to a maker to have it made. My previous experience said that the maker would tweak it to make it better. Wrong! It is one of the most absurd knives I have ever held. To thick sharp edges and my fingers don't sit comfortably on the handle.

Now that I have started down this knifemaking path (9 blades none finished) I draw then make a template in plastic, adjust it, adjust it...
 
I haven't made a lot of knives, I've forged and filed a few, and used stock removal method.

Being a beginner i've found following a drawing vs. following the steel when forging increased my learning. Following the steel I think is following our intuition or subconscious.
A lot of our creativity comes from this in my opinion.

I also have found that imagining , creating my designs in head, then transferring to sketches makes the build easier, each element being more defined.

I feel I should be able to make a knife exactly as drawn, but my skill level is not up to it so I claim artistic lic.:eek:

That's probably clear as mud.
Mark Behnke
 
Early on, I took on custom orders. What Ed had to say speaks volumes. I made the knives EXACTLY as per the drawings and I got in return, "well, I was expecting this, or expecting that..." I no longer do any custom knives at all. I only make what I make, period.

Please keep in mind that I don't have to make a knife to make a living. I am very part time. I suppose that I am the penultimate artisan as far as that is concerned.

Craig
 
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