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Lansky uneven bevel

Discussion in 'Maintenance, Tinkering & Embellishment' started by Obscured, Nov 29, 2020.

  1. Obscured

    Obscured

    4
    Jul 7, 2020
    After I sharpen with lansky angle sharpener I notice the bevel seems to be wider in the middle of the knife. I mostly notice this on wharncliffe blades. If anyone could offer some insight would be appreciated.
     
  2. chalby

    chalby

    44
    Nov 8, 2020
    It depends on how you are using it. I'm assuming you are talking about the lansky guided system.

    The bevel angle will be smaller the closer you are to the pivot of the guide rod. If you clamp the blade near the handle, generally the bevel will gradually become taller towards the tip of the knife because the distance from the pivot will normally increase. You might be concentrating too much on one area/wearing away unevenly, but that would be a guess.
     
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  3. Obscured

    Obscured

    4
    Jul 7, 2020
    yeah its the guided for some reason I wrote angle. I'm normally clamping it in the middle of the 3in blade, and thats where the bevel seems to be tallest with it shorter towards the tip and handle. My first thought was I was using more pressure when It came to the middle but I was pretty careful to keep it even. I'm not terribly concerned about it, the knife is sharp but I'd like to know the issue whether its me or something with the sharpener.
     
  4. 000Robert

    000Robert Gold Member Gold Member

    Mar 28, 2020
    I have never used a Lansky system. I have a Wicked Edge 130. But I imagine that the principles of sharpening would be the same. You should only use enough pressure to hold the stone evenly against the blade edge, and no more than that. Let the stone do the work. That is the way that I understand it.
     
    Obscured likes this.
  5. comis

    comis Gold Member Gold Member

    936
    May 17, 2013
    It does sound like it's not just about the pressure. You might already know this, but have you tried using a marker paint evenly on a bevel? I found the maker trick is quite essential for finding the 'optimal' position for any guided system, and probably universally for any sharpening.

    If you find yourself removing more ink in the middle versus the tip, then maybe it's time to reposition the orientation of the blade. Sometimes even if we have chosen a 'proper' angle to sharpen with, because of the geometry of the blade(between the edge thickness etc), the bevel may not always be completely even. That's why using the marker to help find the optimal position to clamp is vital(at least in my book, YMMV).
     
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  6. midnight flyer

    midnight flyer Basic Member Basic Member

    Jan 12, 2009
    I got a Lansky device back in the 80s sometime. Before there were videos, etc., on how to best use it. I bought it to set the edges on knives as I wanted the bevels to be set so all I had to do was touch up a blade freehand. It took a while to become one with the Lansky, but it is still in my arsenal of sharpening gear. It has its place, but you have to do your part.

    Practice makes perfect. The key with the system is the stroke. Even strokes that slide across the blade are the key. Make sure you hold the stone at about 45 degrees to the blade, and move the stone from the front to the back of it, pushing forward while sliding across the blade. You are literally grinding an edge, so think of how you need to hold the stone to get a clean bevel. I ground up a smaller knife practicing this stroke, top of the stone on the heel of the edge, then a measured stroke to slide across the length of the edge. Think of you hand with the stone in it as a solid device with no flex; hold the stone the same way every time, and make your even stroke the same way every time while making sure the guide rod sits in the same place every time.

    The tip of using a marker is a must if you are using it on a larger (more than 4" for me) as you will need to move the clamp as well. I find that the clamp placement is important too, so if you are sharpening a large knife and need to move the clamp, mark the clamp location as well.

    The Lansky has its place, for sure. I find it really valuable for my traditional pocket knives. Since I set the angles with it, my pocket knives are a snap to touch up with just a few strokes on my diamond rod.

    Robert
     
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  7. Smiling

    Smiling

    Nov 21, 2019
    I sharpen free hand... once I got some practice issues became basically non existent...

    It pays off to learn to sharpen free hand.
     
    MarkN86 likes this.
  8. Mikel_24

    Mikel_24

    Sep 19, 2007
    Is not about the presure, the strokes, not-knowing how to use it or that the system is wrong... is just pure geometry. That's it. If you want an even bevel you need to have the same distance between the pivot point and the contact patch of the sharpening stone on the blade through the WHOLE LENGTH OF THE BLADE. And you don't have that because the further from the clamping point you get, the longer the distance gets, therefore the angle lowers and the edge becomes more acute.
    This
    There is no way arround it, you will have to live with that. If you can't, you will need a system with a pivot point that slides on a fixed height guide paralel to the blade to insure the stroke is always perfectly perpendicular to the edge and from the same distance to the edge.
    And that will only work with perfectly straight edges (or portion of edges) once you reach a curve or the upswept of the tip, all this precission goes out the window.

    And this:
    Mikel
     
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  9. MarkN86

    MarkN86

    504
    Sep 3, 2012
    These guide rod systems make it easy to get a screaming sharp edge but it takes a lot of engineering to follow the contour of a blade evenly. The Lansky system is rather simple as far as guide rod sharpening goes. Don't sweat it too much, that's just the way it is. Still a lot better of a system than those knife mangling pull through "sharpeners" that are so popular.

    I've seen some excellent results from experienced freehand sharpeners, but even best freehand sharpening experts won't always end up with absolutely perfect bevels on each side. In the end, if it's not for show, an imperfect bevel doesn't hurt anything. You can always correct it with the next sharpening.
     
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  10. Obscured

    Obscured

    4
    Jul 7, 2020
    Yeah I figured it might just be that the lansky isn't the most precise. I've always freehand sharpened until recently I decided to give this a try so still feeling it out. Every knife I've sharpened with this system has gotten a good edge so thats what matters. Thanks for help
     
  11. Mistman68

    Mistman68 Gold Member Gold Member

    331
    Apr 7, 2019
    I've been using a Lansky for years, it actually works pretty well once you've spent some time with it. I used to get wider tip bevels but now I can get a pretty even bevel all the way across the edge. A couple things that make a difference are centering the clamp on the blade and the distance from the clamp to the edge. I try and make sure it's as centered as can be and then rotate it so the clamp is perpendicular to the edge at the belly, it may be just barely cocked toward the tip or straight along the spine depending on the shape of the belly. Secondly is ensuring the clamp is ~ 3/8's to 1/2" from the edge, this will control the angle as much as the rod slot on the clamp. Farther from the edge, wider bevel, closer to the edge shorter bevel. I believe getting the blade clamped in properly is key on controlling the edge bevel.

    I don't really believe the angles on the clamp, I think they're close enough though. If your trying to match an existing bevel moving the clamp in or out and playing with the angle slots should get you very close. Personally I just use the 20 for almost everything and reprofile most edges to that angle. After a few years using it I can get very even bevels and a nearly mirrored edge w/the 3k sapphire and a strop.

    A couple friends have different guided systems that cost more $$, I can do anything they can do w/my Lansky. Understanding the geometry of the system and how it applies to making an edge along w/basic understanding of edge geometry will help getting the edges you want. There's a lot of latitude built into it.
     
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  12. Bigfattyt

    Bigfattyt Gold Member Gold Member

    Jun 23, 2007
    I used a lansky for decades. It works to get shap, but by the nature of the pivot system, the angle will change overthe length of the stroke.

    Typically, of you are clamped in the middle of the blade, that angle should be steepest. On longer blades, it becomes even more pronounced.

    I had nor used the system in years and years....8 pulled it out to reprofile a custom Warncliff Kwaiken. Messed up the plunge line while not paying attention. I was sharpening in a dimly lit room, and put a notch in the lovely curved plunge.
     
    Last edited: Nov 30, 2020
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  13. comis

    comis Gold Member Gold Member

    936
    May 17, 2013
    I used to think the same way about guided sharpening system with a pivot, because I too have the issue of uneven bevel from flat part of blade towards the tip. I kept on thinking maybe it was the distance from the pivot that may have caused that. But eventually, I released it was only half the truth. It's hard to explain, but I did see this video which could explain why the sharpening angle remains the same on the flat part of a long blade, so as long the stone could reach it:



    Please do feel free to correct me if wrong, I think the reason why 'uneven' bevel from flat to tip of a blade could happen, is not because the stone is further away from pivot, but it's all about blade geometry(since not all edge is just a straight line) and whether we could clamp at strategic location to compensate/compromise the situation.

    Because of the primary grind/shape/stock thickness of the blade, the BTE thickness of the blade could be different if you trace it from the ricasso to the tip of the blade. And with the different thickness BTE, even sharpening at the same 'angle', the bevel will certainly look different.
    This phenomenon may not be very prominent, if the tip don't have a huge upswept and the blade has relative thin stock.(For example, Spyderco knives). But if the stock is thicker and it's a straight back, then it maybe become more noticeable.

    Also, if a blade is 'tall' in height, and has a straight back design where the tip is swept up high, then the sharpening angle of the flat edge vs tip could again be slightly different. To exaggerate this, imagine a knife with a height of 12" tall blade and has a straight back design--the angle of the stone making contact with the flat edge vs the tip will for sure be different.

    In reality, I think it's always a combination of the factors above and whether we could strategically clamp at an optimal position to mitigate those factors.

    Instead of always clamping vertically to the spine, one could choose to clamp at an angle to offset the uneven bevel and that's why the marker is important tool to tell us whether the current clamp location is indeed a good compromise.(Not saying an 'optimal' clamp position could solve everything, but it surely would help reduce the bevel difference to some extent.)

    I'm sure this is nothing new or even basic to experienced user, but it was an a-ha moment to me when I first realized it. In practice, many may not care to have an absolute even bevel from flat to tip, so YMMV.
     
    Last edited: Nov 30, 2020
    sharp_edge, MarkN86 and Obscured like this.
  14. If the blade is even the slightest bit warped, bent or curved to one side or the other, the flat hone won't make consistent & even contact on all portions of 'straight-edge' profiles like wharncliffe or sheepfoot blades. So, metal removal will be greater in some areas and lesser in others. In such cases, bevels will tend to be wider in the central (middle) portion on one side of the blade, and narrower in the central portion on the other side, with the tip area and heel area having wider-looking bevels on that side. This is because on one side, only the 2 edges of the flat hone will make contact against the bevel, and on the other side, only the central portion of the hone's width will make contact against the blade's bevel.

    Place a known perfect straight edge against the bevel on one side, and compare to doing the same from the other side, to see if the blade is curved, bent or warped. 'Wavy' primary grinds on blades and primary grinds of inconsistent thickness along their length will also have a similar effect on sharpening, leaving the shoulders of the bevels looking 'wavy' as well.
     
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  15. MarkN86

    MarkN86

    504
    Sep 3, 2012
    Blade height variances, distance from guide rod's pivot point, and blade thickness can all impact bevel height in different ways. I used to use a guide rod system and I noticed some oddities, so I switched away from it.

    At the same angle setting and blade thickness a tall kitchen knife will have a taller bevel than a fillet knife, only a higher end guide rod system with a pivot height adjustment could fix this issue.

    A longer blade will see more distortion at the tip, but the bevel may stay the same throughout the rest of the blade. This could be mitigated by readjusting the knife closer to the tip when sharpening that area.

    Blade thickness is a factor. A flat ground blade with a belly and a distal taper may have a taller edge bevel at the heel, thinning at the belly, and taller again at the tip. This is due to differences in blade thickness. That same distal taper in a wharncliffe would cause the edge to continually thin as it goes down the length of the blade. This really gets crazy when you throw recurves into the mix. Some get really jacked up and wonky and some stay perfectly the same, depending on where the guide is set.

    There are so many factors and geometries you'd have to judge it on a knife to knife basis. Either way, the edge bevel might not be perfectly even if the same angle is maintained perfectly with laser accuracy from heel to tip. This effect is increasingly pronounced the thicker the knife is behind the edge.

    I feel like I'm probably completely wrong, or this is more than anyone cares about or wants to read.
     
  16. Mistman68

    Mistman68 Gold Member Gold Member

    331
    Apr 7, 2019
    The Lansky system is ideally suited for blades under 5" IMO. I don't use it for kitchen knives or anything w/a blade longer than around 4". It also isn't ideal for full flat grinds as the blade can rock in the clamp. I always put tape under the clamp, w/a FFG I build up a little tape on each side and clamp the heck out of it making sure the edge is centered then apply light pressure on the stone and check centering often. I also make sure the gap at the rear screw is considerably wider than at the front so the clamps have more angle on the blade. This changes the 'actual' sharpening angle a bit but that's adjusted w/the clamps position to the edge. Like I mentioned earlier, the stamped angle #'s aren't perfect and the position of the clamp changes those #'s slightly but it's easy for me to repeat the angle on a previously sharpened knife.

    As has been mentioned previously, some blades just don't have very good factory edge geometries. One edge may have a different edge bevel than the other which usually results in one bevel being wider than the other after sharpening. The tip is often thicker which will cause the bevel to widen approaching and through the tip. A lot of times the grind near the choil is odd and takes time clean up side to side and may appear different on each side once done. Or the wavy, warped, crooked or badly ground edges, it happens.

    Edge geometry is whole genre in the knife world and takes some time to understand, sharpening a knife is only part of it. I'm still learning and I've been at it a while.
     
  17. midnight flyer

    midnight flyer Basic Member Basic Member

    Jan 12, 2009
    To be sure (and I completely agree!) that if you compare the $50 spent on a Lansky 5 stone system and the stand (buy the stand... at $15 it is a must)to a $400 plus Wicked Edge/KME system, the Lansky falls short. No doubt! And in that light, it is far from the best system.

    I can tell the folks that use the Lansky and have come to understand its shortcomings. Not good for longer blades (say, over 4") ? Check. Understand the placement of the blade clamp? Check. Get the fact that there is a learning curve? Check. Understand that there will be a degree or two difference across the blade edge representing up to a couple thousands of an inch in its length? Check.

    Personally, and this is NOT a shot at those that do, I don't need to be able to tree top hair. I don't need to read newsprint in the reflection of the sharpened edge. I don't need to slice a falling sheet of paper in two in mid air. If I did, I would probably be in for one of those few hundred dollar systems.

    But I grew up free hand sharpening (high five to all of us that were the original convex edge guys... we couldn't help it!) and loathed 2-3 hours on the Arkansas stones to get the knife edge where I wanted it. I need a sharp knife, not nearly as most here. I sharpen to 1200gr, then might strop it with green polish if needed. Mostly not. My knives will all shave hair off the 1200gr diamonds, and that is close enough to sharp for me. And while I can get even bevels free hand (99% of my sharpening method) I realize that even then the bevels aren't perfect.

    << I >> bought the system because I could use it to rapidly grind away the factory edge that I didn't like on a blade. Back in the 80s the blade sharpening was piss poor on my CASE, only a little better on my Bucks, Bokers and Schrades. The common thinking then was anybody that loved their knives was going to put an edge on it that they liked, one that they found most useful. It was considered by many, including me, as part of the ritual of "making a knife your own". So mass knife makers (as above) rarely got an acceptable edge on a knife. I found that I could work my way through the stone grits easily and edge just about any knife I had in just a few minutes as compared to working it over the stones for a few hours. And yes, I screwed up a couple of edges on blades before I got it where I wanted it.

    Still in the sharpening box, when I get one of the harder steels so prevalent these days, I pull the old boy out and put it to work. Thankfully, most of the knives I have purchased lately all have acceptable edges and I can touch up on the diamonds free hand and be done. It still sees regular service though... I seem to have a lot of friends that have no idea how to sharpen their knives.

    Robert
     

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