The negative blade angle wharncliffe that I wish existed

[carpdiem]

So, first off, these details come from a knife design I submitted to Spyderco, and which they rejected with a very appreciative note. No sour grapes at all, and I'm glad they took the time to review it.

That said, I'm really not going to do anything else with this, and so I'd rather get the ideas out there so that there's a better chance they'll influence future designs somewhere, and so that I can eventually buy a knife like this. :)

The negative blade angle wharncliffe

Most knives on the market focus on general purpose utility for outdoorsmen / etc. This leaves you with "belly" on the blades, and knives optimized for use while standing up, and/or while exerting really significant force. That's fine if you're a hunter or a fisherman or a hiker, but I'm a physicist and an engineer, and I wish I had a knife optimized for precision and benchwork.

What's different? Well, obviously the blade angle. But why?

Most regular knives require ulnar deviation of the wrist to engage the tip or to perform pull-cuts (in particular, when cutting material along a surface). in practice, this also includes the very common tasks of, say, opening envelopes or packages. With this "negative blade angle", ulnar deviation of the wrist is eliminated for these use cases.

To improve dexterity for precision use and for pull cuts, you can push the spydie-hole forward to enable more grip options, and provide a deep choil and handle back ramps.

Finally, because the negative blade angle reduces performance for piercing materials, you can leave a large thumb ramp, angled to provide an aligned surface for pushing on with your thumb during piercing motions.

And, of course, the closed profile should leave no nasty corners or acute edges to catch your hand on when reaching in/out of your pocket (original Paramilitary, I'm looking at you!).

Obvious questions:

Why not just use a hawkbill?
I like to sharpen on benchstones. Negative angle wharncliffe gives you all of the hawkbills' tip-precision with none of the sharpening difficulties!

Do you really do that many pull vs push cuts?
Yes. Honestly, my regular routine is probably ~80% pull cuts, from packages, to model making, cutting materials along a surface (practically every day at a workbench!). Many of these more delicate tasks end up being done with x-acto knives, which... suck, and dull quickly, and often have awkward, slippery, round-profile handles that aren't nearly as good as I wish they were.

[Pancake]

I really dont have any needs for this kind of knife, but I truly love your input and all desing are research that you have done.
It is a very purpose build knife, but I have no problems with that and to be honest, it looks very polished.

Do you have any plans to make an actual prototype?

[Fireman]

I’m Wharning you... :D
We have a Sage, a Shaman, is this is a Wharlock?
But seriously, I like this.

[carpdiem]

I really dont have any needs for this kind of knife, but I truly love your input and all desing are research that you have done.
It is a very purpose build knife, but I have no problems with that and to be honest, it looks very polished.

Do you have any plans to make an actual prototype?

Thanks for the kind words, and I'm happy to share it!

You can see the 3d printed prototype in the pictures, but I have no plans to go forward and make metal prototypes. The cost of doing that is prohibitive unless you're already set up for it.

[Fireman]

I can almost see it as a Wharnto. A tanto-Wharncliffe hybrid. Just imaging the tip portion with a chisel front portion being level when held in the position shown. The blade shape as is reminds me of the Pterodactyl

[kobold]

It might be not so expensive to create this as a fixed blade. Maybe just using an old saw for instance. It is a neat idea and design. I use Olfa rotary blades, a Kiridashi, a Vic Spirit and a thinned out Cutjack in the workshop, but this is different.

[juggler]

The blade shape as is reminds me of the Pterodactyl

If this knife is ever made, I think we already have the perfect name :)

[Superfool]

The blade shape as is reminds me of the Pterodactyl

If this knife is ever made, I think we already have the perfect name :)

Where is the 'upvote' button on this thing?

[Superfool]

The negative blade angle wharncliffe

I love the idea, and I think you make a very solid case.
Do you find you are getting any sustained RSI from your current arrangement?
What metal would you choose?

I am loving this effort level you maintain. It's intense.

[benben]

Great presentation! Do you by chance work for a marketing firm?

[Michael Janich]

The negative handle-to-blade angle has been a signature feature of Ed Schempp's designs for years. It is an underappreciated concept. His Balance and Barong designs were of very similar spirit.

Stay safe,

Mike

[Sonorum]

First off: I really see your point. I also cut a lot down and into materials and a majority pull cuts. I really like wharncliffes!

What I often do is shift my grip because I also find the wrist angle uncomfortable. The Native will serve as an example because I can't bring out a wharncliffe right now (carrying a sleeping baby). This isn't perfect but relaxed the wrist at least.

I grab the knife a bit shifted sideways. I think I picked it up working in kitchens but I can't really remember...

Position 1: wrist angle.


Position 2: "side" grip with thumb on the side of the blade.


Sorry about the poor photo quality.

[Ez556]

That's a great design. I could totally see this being made and called the Wharlock or or Pterodactyl. I really like the thought that went into the design, especially the closed profile. It looks amazing, its a shame Spyderco is rather uninterested in it, because I think it would be a great fit in their line. I almost get the feeling it's a mix of a P'kal and Swick 5.

[RustyIron]

I'm a physicist and an engineer, and I wish I had a knife optimized for precision and benchwork.

I'm a blue collar college dropout with a myriad of tools for cutting everything from tree trunks to tiny holes in exotic metal. I see the weakness of such a knife as the way it forces the user to use only the tip of the blade, and the way it makes using the rest of the blade awkward. For everyday knife use, I prefer to reserve the tip of the knife for those times when it's really needed, and try to use the mid section when possible.

When I want a knife "optimized for precision and benchwork," I might choose an X-Acto style knife from the drawer, and make a couple passes on a stone to bring it to uber-sharp level. A big fat pocket folder really isn't a tool for precision benchwork, no matter how you orient the blade.

[ladybug93]

i think people do a lot more pull cuts than they realize. i have thought about this a lot lately because, in teaching my kids to always cut away from themselves and then having them watch me use my knife, i've seen how often i'll draw my knife toward me instead of pushing away. it just feels more precise and controlled because of our musculoskeletal structure.

that said, i can easily see this knife working for push cuts as well. you would have to lead with the tip and slide toward the handle. this would give a great angle for working, as you mentioned in your piercing piece. when i carve feather sticks for a fire, for example, i'll often hold the knife in that type of a position and use the motion i mentioned above.

i guess what i'm saying is that this looks like a good, useful and utilitarian design. i don't think it is necessarily as purpose-built as some would think and it would lend itself well to a lot of cutting tasks.

good job with the design and mock-up. i'm kind of surprised spyderco passed on it, but maybe they're just stretched too thin right now trying to get their own designs out the door.

[carrot]

I really like what this design represents. I've always appreciated the very slight negative blade angle already seen in the Delica and Endura and many other Spyderco models which I prefer strongly to straight angle designs by most other makers. I think taking the negative blade angle further adds a lot to the cutting aggression of the tip.

I wonder, could you "prototype" this on an existing Delica or Endura by cutting a new locking notch into the tang? It might be tough because it's hardened steel, but it might get you closer to a working knife in this format.

[The Meat man]

I like it. It looks like it combines the "hook-like" cutting efficiency of a hawkbill with the more-easily maintained edge of a wharncliffe. Plus, in a package that looks like it would carry quite well.

I agree with ladybug. It looks like it'd be a lot more versatile and general use than some might think.

[JRinFL]

So, first off, these details come from a knife design I submitted to Spyderco, and which they rejected with a very appreciative note. No sour grapes at all, and I'm glad they took the time to review it.

<snip>

It is well worth your effort to contact Boker and possibly a few other makers. This is a well thought out design and seems useful to good number of users. Obviously, the other makers will not be able to use the round opening hole.

[Ez556]

I don't think it is necessarily as purpose-built as some would think and it would lend itself well to a lot of cutting tasks.

I agree. I also don't think the design limits you to using just the tip either. I'd argue it actually makes it easier to use the entire edge more than a "normal" wharncliffe because the angle puts more of the edge past your knuckles and makes it more available.

[Ez556]

Obviously, the other makers will not be able to use the round opening hole.

Nor the Compression Lock.