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Thread: Edge Pro Apex?

  1. #21

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    I finally found a pic of my setup. this is before I changed to sandpaper on the makitas. I had three grits and I would go from rough grind to about 90% sharpened in 2.5 minutes.

  2. #22
    Senior Member ThEoRy's Avatar
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    Quote Originally Posted by cncrouting View Post
    huh? the geometry is whatever you choose it to be. just like hand sharpening. unless you change the geometry over the knifes curve.
    But that's the problem. The jig systems do not compensate for the curve so over time they end up changing the geometry. I don't think asymmetrical sharpening is easily achieved either. This also changes the geometry. Let's not even talk about single bevel.
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  3. #23

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    Quote Originally Posted by ThEoRy View Post
    But that's the problem. The jig systems do not compensate for the curve so over time they end up changing the geometry. I don't think asymmetrical sharpening is easily achieved either. This also changes the geometry. Let's not even talk about single bevel.
    with the edge pro you move the knife so you can keep the same angle all the way through. with the wicked edge you choose the part of the blade you want the geometry on then the whole blade get it it will change with the curve of the blade and i think the length. with the edge pro you move the knife length wise and when you get the the curve of the tip you tilt the blade to get the same angle. that I found tricky especially with my left hand. but once I worked out the right angle on my benchmade it came out perfectly even and uniformly sharp. the edge was pretty much the same as my new Murrey career knife that was hand sharpened. pretty close to the same sharpness and the same evenness. this is a pretty poor video but as long as the part of the blade you are sharpening is even with the edge of the rest the angle will be the same. but you have to move the blade to do it.

  4. #24
    Senior Member bennyprofane's Avatar
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    Quote Originally Posted by ThEoRy View Post
    But that's the problem. The jig systems do not compensate for the curve so over time they end up changing the geometry. I don't think asymmetrical sharpening is easily achieved either. This also changes the geometry. Let's not even talk about single bevel.
    With Bogdans jig (the one on bench stones which shaprchef posted) you can lift the handle to get the curve at the tip, just like free hand, you can even fine tune the clip which holds the knife (theres either a magnet or clip) with little screws to adjust the symmetry or asymmetry, if you want that. It's basically exactly like free hand sharpening, just that you keep a nearly 100% perfect angle. And of course, you can still thin your blades.

    It's interesting if you follow the entire history of how sharpchef came to use this jig. He free hand sharpens since 15 years and it basically started out with him challenging another user on the German forum that a blade that he sharpened free hand would keep it's sharpness longer than one sharpened with Bogdans jig and he had to admit defeat. Since than he has been experimenting a lot with this jig and gets constantly better results than free hand. At home he still free hands but working in canteen kitchens he needs edges which last and Bogdans jig really delivers. I recently visited him with nutmeg and his knives don't wedge or stir at all but cut perfectly.

    Of course, free hand sharpening is a really nice and relaxing thing to do and most don't have a need for this jig (using this jig is actually also quite nice and not monotonous like an edge pro or sharp maker, it's like someone guiding your golf swing and could even be used as a teaching system for free hand).

    Disclaimer: I recently got the smaller version of this bench stone jig and quite like using it. I feel that it already has improved my free hand sharpening as I am still quite a novice with less than a year of practise. Here is a little video I made: https://vid.me/TSv5 And here are two pictures: http://imgur.com/a/ULGF8

  5. #25
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    I think that Benuser and Theory are not talking about the profile of the knife (the shape of the edge from heel to tip). They are talking about a change to the cross sectional geometry of the blade. The part of the blade behind the edge will get thicker and thicker as the edge moves up with each sharpening. This causes the knife to wedge in food even if the edge is super sharp, making the knife a poor cutter. It is corrected by thinning the blade. This can be accomplished with an Edgepro (especially the pro model) on Euro knives. The issue with Japanese knives is that the cross sectional geometey is almost always highly assymetrical (even if the edge is 50-50). If they are thinned as though they were symetrically ground they will begin to steer in food. So if you use an Edgepro on a Japanese knife you will need to adjust the angle when thinning each side. Not only that, most Japanese knives have a degree of convexity in the grind which helps with food release. The Edgepro simply cannot fillow this convexity.
    "My greatest fear is that when I die, my wife will sell my knives for what I told her they are worth"

  6. #26

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    If I have to thin the one knife that requires it I will send it or take it to the maker for it. but I usually only need to sharpen once a month so it will not happen anytime soon.

  7. #27

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    Quote Originally Posted by Sharpchef View Post



    I talk about systems like this.....

    And you can always let the system go, and thin your blades manually, but it would be possible with this system too, i can sharpen 0 degree angle with it, no problems..... Even Yanagibas get a new level of sharpness...... Because the Angle control is much better then with EP Systems and i got a pressure control as well....

    Btw. Sorry for so much offtopic.......

    Greets Sebastian.
    that looks great though I would hate to see the cost.

  8. #28
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    Quote Originally Posted by Nemo View Post
    I think that Benuser and Theory are not talking about the profile of the knife (the shape of the edge from heel to tip). They are talking about a change to the cross sectional geometry of the blade. The part of the blade behind the edge will get thicker and thicker as the edge moves up with each sharpening. This causes the knife to wedge in food even if the edge is super sharp, making the knife a poor cutter. It is corrected by thinning the blade. This can be accomplished with an Edgepro (especially the pro model) on Euro knives. The issue with Japanese knives is that the cross sectional geometey is almost always highly assymetrical (even if the edge is 50-50). If they are thinned as though they were symetrically ground they will begin to steer in food. So if you use an Edgepro on a Japanese knife you will need to adjust the angle when thinning each side. Not only that, most Japanese knives have a degree of convexity in the grind which helps with food release. The Edgepro simply cannot fillow this convexity.
    No they are talking about the fact that the angle is fixed at the point of connection and doesn't follow the curve of the knife.. hence as you move the blade around the angle shifts.

    Not to mention once you talk about shifting for asymmetry then what the heck is the point? Might as well just practice freehand a bit more.

    Sorry but jigs just arent flexible to cope with long or curved blades. And that makes sense. Their positive is that they hold an angle. But that is also a negative depending what you are sharpening.

    Remember angle is determined by height and length. Either of them change and the angle changes.

  9. #29
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    I should at the jig that sharpchef uses seems a lot better but I still think that is would have the same issue. Otherwise rather than giving you your angle it would just assist in holding it... which again I don't see the point

  10. #30
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    Quote Originally Posted by malexthekid View Post
    No they are talking about the fact that the angle is fixed at the point of connection and doesn't follow the curve of the knife.. hence as you move the blade around the angle shifts.

    Not to mention once you talk about shifting for asymmetry then what the heck is the point? Might as well just practice freehand a bit more.
    Yes, the angle does change because of 2 factors:
    1) The heel end of most gyutos is a lot taller than the nose end, which means that the heel sticks out further and receives a lower angle.

    2) As the stone arm swings from side to side, the length of arm effectively increases the further one gets from the midpoint of the stone arm's arc.

    I was curious, so I've just measured the magnitude of this change. I used my knife with the greatest variation in blade heigh (270mm Fujiwarra Kanefusa FKM gyuto).

    At a set 15 degrees, factor (1) Accounted for a 1.3 degree variation (which would obviously change gradually down the length of the blade). Factor (2) accounted for 0.3 degrees at the nose end but only 0.1 degrees at the heel end. This would obviously vary from point to point depending on where the blade was positioned relative to the blade table.

    So there is a 1.4 degree maximum variation in the angle produced. I suspect you would have to be a pretty good sharpener to do better than this freehand.

    I agree that the jigs are fiddly WRT asymmetry at the edge and cope very poorly with asymmetry in the grind when thinning.
    "My greatest fear is that when I die, my wife will sell my knives for what I told her they are worth"

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