Wicked Edge / Edge Pro

[ricklee4570]

For a perfectionist the question would be, should you pull and rotate on the Edge Pro? If you do, then you would have to pull and rotate exactly the same every time or your angle would not be the same everytime. Would this affect the edge? Probably not unless you are shooting for record book sharpness at the max. Still, even with the Edge Pro, it is much easier to leave the knife on the table and sharpen without pulling and rotating.

As a matter of fact, I have watched Ben Dale, the creator of the Edge Pro, leave his knife on the table while sharpening a long kitchen knife.

So the advantage of pulling and rotating seem minor at best to me.

If you have either the W.E. or the Edge Pro, you will, with practice, be able to achieve your sharpening goals. Personally, I think the Edge Pro uses better stones. But I use and like both systems.

 

[fockewul]

For a perfectionist the question would be, should you pull and rotate on the Edge Pro? If you do, then you would have to pull and rotate exactly the same every time or your angle would not be the same everytime. Would this affect the edge? Probably not unless you are shooting for record book sharpness at the max.

I believe you answered your question yourself. Mind you, I consider myself a perfectionist (hence the choice of guided systems), but not to that extreme.

 

[MConstable]

My 2 cents...as a casual user...just my own knives, mostly kitchen knives etc., the edge Pro is pretty difficult for me to use on smaller knives/multi tool blades/Swiss army knife blades etc.
I'm sure practice makes perfect, but I'm looking into the Wicked just for my smaller knives.

 

[CrimsonTideShooter]

My 2 cents...as a casual user...just my own knives, mostly kitchen knives etc., the edge Pro is pretty difficult for me to use on smaller knives/multi tool blades/Swiss army knife blades etc.
I'm sure practice makes perfect, but I'm looking into the Wicked just for my smaller knives.

How would the wicked edge handle a larger knife like the junglas?

 

[clayallison]

How would the wicked edge handle a larger knife like the junglas?

Going from the specs on this page - http://www.eseeknives.com/junglas_machete.htm, it would handle it very well.

 

[cbwx34]

In going back and reading the thread, I think a little confusion may have been created... most of the "angle doesn't change" posts relate to the straight portion of the blade. I don't think there's any disagreement that the angle does change when the blade curves and changes height. What's interesting is the height change increases the angle, following the curve decreases it. Which is greater depends on the knife shape, where it's located in relation to the pivot, etc. and its probably easier to just mark the edge and see what path the stone takes.

What makes the bevel widen depends on several factors: the thickness of the blade change as it approaches the tip, the angle change in sharpening, are a couple. I also think something else is involved that can make a bigger difference. Consider the following photos...

This is the same knife that I marked with a Sharpie and made 3 passes on a guided sharpener with a fine stone to show the travel of the stone. The knife was held in the same position each time. No adjustments were made to the guided sharpener. The top photo shows the stone tracks a higher path... more passes would widen the bevel before it would reach the edge. (More passes would show it better, but I tried to keep both the same.) The bottom photo shows the stone tracks a lower path... dropping immediately down to the edge and following the curve. So what changed? It was whether or not I allowed the stone to rotate or 'roll' on its rod (this was on an EP btw, but its not specific to that device). If you allow the stone to rotate, it will drop and track closer to the edge. Depending on the knife though, and you can see it in the lower photo, if you don't pay attention you can end up flattening the "nose" of the blade... because you will remove metal faster at the tip than the belly. (You can also knock the tip off if you let the stone roll over it, but that's a separate issue). If you don't allow the stone to rotate, it will try and track higher... and widen the bevel. So, if you hold the stone on any guided system too tight and don't allow the rotation, the bevel can widen. This can actually be more visible on knives with less belly, because it can be harder to feel the stone wanting to roll... and the sharpener might inadvertently "override" it. This can also occur sharpening freehand, depending on what method is used to allow the blade to track around the belly to the tip.

Just thought I'd mention it, since 'bevel widening' was brought up in the thread.

cbw

 

[BladeChemist]

Going from the specs on this page - http://www.eseeknives.com/junglas_machete.htm, it would handle it very well.

Can you elaborate?

 

[clayallison]

Sure. The specs list the knife as 10" in length, 0.1875" thick with a high saber grind. The steel is 1095. 10" is a very comfortable length to work with in the sharpener. The high saber grind makes it easy to clamp and the thickness is well within the range of the clamp's maximum width of 0.33". It would be good to clamp this knife closer to the front third of the blade to adjust for the widening bevel along the curvature. This diagram shows how that adjustment works:

 

[clayallison]

A quick note on the drawing I just posted. It's interesting to observe that as the stones move around the curve of the blade (and rotate on their guide rods as CBWX34 remarked on so well) the geometry reverts to being more intuitive because the plane of intersection between the stone and knife changes throughout the curve and the rotation of the stone on the rod and the angle is just the top of the right triangle created. In the section where the blade is closer to the pivot point, the effect is actually reversed as you get toward the tip and the angle starts getting more obtuse again as the edge of the knife is lower in relation to the pivot point. CBWX34 makes a good point about using the Sharpie to find the sweet spot that keeps the angle most constant along the curve. In the diagram, the sweet spot would be about halfway in between the first curve drawn and the second.

 

[clayallison]

My 2 cents...as a casual user...just my own knives, mostly kitchen knives etc., the edge Pro is pretty difficult for me to use on smaller knives/multi tool blades/Swiss army knife blades etc.
I'm sure practice makes perfect, but I'm looking into the Wicked just for my smaller knives.

The smaller knives work well. There is some limitation to the angle because of the narrowness of the blades. These pics show a fairly small blade with a 17.2° angle:

 

[handamerican]

Clay - that angle indicator is pretty cool, I can see a bunch of applications in other areas but it fits right in with your machine.
Keith

 

[BladeChemist]

Sure. The specs list the knife as 10" in length, 0.1875" thick with a high saber grind. The steel is 1095. 10" is a very comfortable length to work with in the sharpener. The high saber grind makes it easy to clamp and the thickness is well within the range of the clamp's maximum width of 0.33". It would be good to clamp this knife closer to the front third of the blade to adjust for the widening bevel along the curvature. This diagram shows how that adjustment works:

I was thinking 'cool picture' for a moment then observed that the author rotated the sharpening stone near the tip of the knife in a manner impossible for the W.E. as it is designed. I'm also not sure what the angles near the hilt of the blade are there for, as they're not located on the edge- any explanation?

cbwx34 That's an interesting set of pictures. Although I hope you don't let the stone roll - that would translate the point of pressure or contact parallel to the guide rod. Depending on habits, that could mean an increase or decrease in sharpening angle. I think you've pointed out a very important skill that is required to operate both the E.P. and the W.E. in an exacting manner- you have to direct pressure in the exact center of the stone and down at the blade at every point on your stroke. Would never have imagined it would make that much of a difference!


And last but not least- I found W.E.USA's comparison page between the E.P. and the W.E...suffice to say: it's on

For the benefit of reality I'll correct the W.E.'s column.

• Powerful vise that eliminates knife slippage ...the blade is sandwiched between the stone and the blade table and assisted by gravity and a steady hand? I suppose it's not full-proof...
• Easy two-handed sharpening capability that dramatically reduces sharpening time Okay, that is pretty nice
• Alignment tools for mounting your knives in the vise in exactly the same location every time which makes for extremely quick touch-ups No?? Every knife has a 'built-in alignment tool"- tip to one edge of the blade table, pivot the blade until the edge just covers the other side of the blade table. Extremely fast and exact. No need for tools.
• Two-sided sharpening handles for efficient work flow Also admittedly very nice
• Brace to prevent flexible knives from bending during sharpening No again? How do you bend a blade on the blade table when it...can't bend?
• Optional Ultra Coarse/Extra Coarse (50 & 80 grit) diamond stones (2 each) Optional? If that's the case there's plenty of "optional" DMT stuff for the E.P.
• Optional Extra Fine / Ultra Fine (800 & 1000 grit) diamond stones (2 each) Again, optional meaning you can buy the diamond stones from Ben or the other aftermarket sources
• Optional leather strops with stropping compound Yup, optional polish tapes. Or make your own strops, or use an old tape with polishing compound etc etc
• Sharpens scissors Given.
• Price (depending on selected options or accessories) The sky's the limit for either system depending on your funding and lust for extra or aftermarket stones and strops.

 

[clayallison]

I was thinking 'cool picture' for a moment then observed that the author rotated the sharpening stone near the tip of the knife in a manner impossible for the W.E. as it is designed. I'm also not sure what the angles near the hilt of the blade are there for, as they're not located on the edge- any explanation?

Okay, I re-drew the picture to address the orientation of the stone you commented on. I drew it first that way to illustrate that the plane of the stone in relation to the straight edge is what was being measured and it seemed to be easier to see in that orientation. As can be seen below, it doesn't matter if you rotate the stone in the picture to match the angle of the guide rod, the angle of intersection of the two planes remains the same. As you get into the curve, the plane changes, forcing the angle change.

The angles marked further back on the blade are there to show that if you move the knife back in relation to the pivot point, the angles change. You have to imagine the section in front of the curve there being gone after the knife is moved back. I've removed the center portion of the blade in the image below to make it more clear:

 

[Twindog]

Thanks for the great explanation, Clay. In looking at the first position, where the front of the blade is further out, leading to more acute angles, I wonder if that differential in the angle isn't a good thing for most knives.

The most acute part of the blade near the tip is where you'd normally do fine detail work and is therefore the part that you'd want to be more acute, while the chopping part of the blade holds what ever angle you set.

It strikes me that you could position the knife in the Wicked Edge to maintain a constant angle or a substantially reduced edge profile near the tip.

I haven't heard this being discussed as a "feature," rather than an "issue," and would like to hear your thoughts.

 

[clayallison]

Thanks for the great explanation, Clay. In looking at the first position, where the front of the blade is further out, leading to more acute angles, I wonder if that differential in the angle isn't a good thing for most knives.

The most acute part of the blade near the tip is where you'd normally do fine detail work and is therefore the part that you'd want to be more acute, while the chopping part of the blade holds what ever angle you set.

It strikes me that you could position the knife in the Wicked Edge to maintain a constant angle or a substantially reduced edge profile near the tip.

I haven't heard this being discussed as a "feature," rather than an "issue," and would like to hear your thoughts.

Twindog, I find exactly what you're saying to be true on most all of my hunting and kitchen knives and EDCs; having the belly a little more acute has its advantages. When it comes to 'feature' vs 'issue,' I think you're right there too.

 

[BladeChemist]

^^Oh, and I didn't mean an disrespect for the picture comment, I think we're all very lucky that you and others have spent this much time on computer graphics and real-life setups in our search for a better understanding of this system . I don't know of any other thread on the web that has gone this deep into discussing the mechanics of the W.E.

With that said, I can see that I've still not convinced you that the sharpening angle has to change as you move down the blade, and I think there will be in impasse until I or someone else can show it mathematically. But it will be done in time.

I do want to inject an "absolute" into this thread: assuming the blade width is the same, if the bevel width changes the sharpening angle has to change. Thoughts?

P.S. - Clay- I just ran across your blog and I can't believe I didn't put two and two together sooner (and the reason why others were thanking you for your input). I just want to say it's very nice to have one of the W.E. co-inventors gracing our presence in this thread and taking time out of what must be a very busy schedule to share your thoughts- thanks for being here!

Edit: I figured out where you and others are getting hung up (an attempted simpler re-explanation of what fockewul was getting at). The line originating from the pivot point will always pass through the plane - yes - but mentally place the sharpening stone on that line and you should see that it has to rotate out of that plane when it's hitting the edge (except for sharpening straight on). It's counter-counter-intuitive and trust me- every time I see your images and the models others have posted my brain tries to second guess itself, but the reality is the bevel and angle have to change. Anyways, my brain hurts, does anyone else's?

Edit: Argh- now I'm wondering if I'm completely wrong again. Someone help me out- does the bevel change along such a straight edge? I'm thinking too hard here- the stone does rotate as it goes down the edge, but it rotates to stay in the sharpening plane. Or not. We or I better figure this out before too many people are convinced of the wrong concept. Pre-emptive apology if I'm wrong.

 

[hardheart]

As can be seen below, it doesn't matter if you rotate the stone in the picture to match the angle of the guide rod, the angle of intersection of the two planes remains the same.

But one plane has diamond abrasive on it, so you can cut the blade and form a new bevel if you are able to contact the stone to the steel at the different angle. Of course, you could also rotate the stone to where it only contacts on the edge of the abrasive plate and make your own serrations in the edge. Using the device the right way, you just resharpen at the chosen angle

The angles marked further back on the blade are there to show that if you move the knife back in relation to the pivot point, the angles change. You have to imagine the section in front of the curve there being gone after the knife is moved back. I've removed the center portion of the blade in the image below to make it more clear:

It strikes me that you could position the knife in the Wicked Edge to maintain a constant angle or a substantially reduced edge profile near the tip.

And this is where I came in this thread. Want the same edge angle at the curve? Move the knife in the clamp.

 

[clayallison]

^^Oh, and I didn't mean an disrespect for the picture comment, I think we're all very lucky that you and others have spent this much time on computer graphics and real-life setups in our search for a better understanding of this system . I don't know of any other thread on the web that has gone this deep into discussing the mechanics of the W.E.

With that said, I can see that I've still not convinced you that the sharpening angle has to change as you move down the blade, and I think there will be in impasse until I or someone else can show it mathematically. But it will be done in time.

I do want to inject an "absolute" into this thread: assuming the blade width is the same, if the bevel width changes the sharpening angle has to change. Thoughts?

P.S. - Clay- I just ran across your blog and I can't believe I didn't put two and two together sooner (and the reason why others were thanking you for your input). I just want to say it's very nice to have one of the W.E. co-inventors gracing our presence in this thread and taking time out of what must be a very busy schedule to share your thoughts- thanks for being here!

Thanks BladeChemist, I've really enjoyed the discussion. I put it to the guys on the physics forum to make a proof of the problem back in July but I haven't gotten any takers yet. I took no offense about the drawing, maybe felt a little foolish for not setting it up more clearly.... I did post a link to the eDrawing file on my blog if anyone wants to look at it. You can use the free eDrawing Viewer to open it and manipulate the model so you can see it from a variety of sides. Just let me know if you'd like the link.

I do want to inject an "absolute" into this thread: assuming the blade width is the same, if the bevel width changes the sharpening angle has to change. Thoughts?

I think that's close to correct. I would add that it's true if the blade thickness is also uniform. It would be possible for the the bevel to become wider if the blade were thicker in some section without an angle change or a change in the width of the knife.

 

[hardheart]

the primary grind also needs to be centered

 

[CrimsonTideShooter]

So if I buy the EP apex 4 are the polishing tapes it comes with enough to put a mirror edge on my knives?