Chef’s knife w/ convex factory grind (Mac Mighty)
- This topic has 31 replies, 6 voices, and was last updated 01/20/2018 at 8:48 pm by
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This is a really interesting case, as I don’t recall ever seeing a micro-bevel on a belt-sharpened edge before. What’s more, the micro-bevel is really small and looks to have been done with some hand honing operation, either bench stone or some guided system like WE or EdgePro or Lansky. Somebody had to know what angle will reach the apex, as taking more strokes to find it would have greatly increased the width of the micro-bevel. I typically use a 20 dps micro-bevel on a 17-degree edge and three very light strokes with my 1000-grit stones will make a bevel twice that width. This one looks like a single, very light stroke with a medium-grit stone; maybe 1000-grit.
Now that I’ve got that out of my system, I’ll have to give it a try. I just did a batch of knives for a friend. Most weren’t worth more than a few dollars, so I hit them with a 600-grit belt on my 1X30 Harbor Freight sander, then a few quick passes at the buffing wheel with pink scratchless compound. All sliced phone book paper easily.
From what I see in Graphite’s photos and read from his posts (assuming 15 dps as the main bevel width) it looks like the blade is only about 0.006″ thick at the shoulders of the main bevel. This means there is very little metal to be removed, no matter what the final decision is on configuration. I would start with 1000-grit and drop back to 800 if the progress was slow.
Final comment: That’s a really impressive factory edge, even without the micro-bevel. Looking at the first and second photo, it looks like the formation of the main bevel was part of the final finishing operation – the grind lines on the faces and the bevel (convex) grinds seem to be the same or very nearly the same. As though the fellow putting the final finish grind swept right through into the convex bevel. I don’t see signs of a polishing step in the convex bevel and am a bit puzzled by this.
Is it possible that the micro bevel that is on the knife was in fact put on by the use of the ceramic hone used to maintain the knife? It seems like a reasonable explanation to me.
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The one pics looks like part of it was, to me at least. The differential scratch pic. If the same hone was used, I would expect the same scratch pattern though slightly different orientation.
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Marc, on my angle logging comment, what I’ve been doing is logging both the coarse angle setting (i.e. the setting on the angle rod) and the fine angle (using the height gauge on calipers, measure the height of the fine adjuster screw above its holder). That way I can replicate the whole coarse plus fine position for the next time I do the same knife (assuming I position the knife itself the same). Or in theory, that’s how it would work.
From the stone compensator videos I’ve seen, I seem to recall some stones varied enough to need to move the coarse adjuster +/- 1 degree notch, not just the fine adjuster. My trizact holders measure 1.15″ thick (across both faces) while the diamonds measure 1.18″ so they’re pretty close to start with (and the actual difference in-use is half that, so call it about .015″).
But your question gets me thinking, while that coarse/fine logging will work when I’m trying to replicate the exact angle for using same stones I used before, I’ll really need to use an angle cube if I change to stones of a different thickness from one sharpening to another. In that case I’d need an absolute angle reference, not just a relative one. So a properly functioning angle cube would be the tool for the job.
BTW, I previously mentioned my angle cube repeatability issues and that I haven’t been relying on it. My Wixey cube uses what they call “Dead Level” and they claim it is “permanently calibrated at the factory and should never need re-set.” They do offer up a way to override it, but I hesitate to do that since I’m not sure my issue is a calibration problem. The readings are accurate, just not to the .1 degree accuracy due to the lack of repeatable measurements. tcmeyer mentioned something interesting in that other thread (extraneous vibrations e.g. due to music playing in the background) that I had not thought about before but it does sound plausible. I’ll have to mess with it some more.
Also, the Wixey model I have only has magnets in the base. So I’d either zero it then put the base on the stone for a hands-off approach (and subtract 90* from the result) or I manually hold the Wixey on the stone on one of its sides, but any vibrations in my hand will translate, even if I think I’m being steady. I tried both, and both had repeatability issues, but I’ll look at it again later. Using just the base has the advantage that it doesn’t include any error in the sides of the cube not being 90.00 degrees, but the disadvantage is to get a direct angle reading I’d have to hold it manually on a side face. Also, I may consider getting one of the dual-axis Floureon models since it sounds like you guys have been pretty happy with those.
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I often listen to YouTube or music when sharpening, and have not had issues with vibrations though I have powered Bookshelf speakers on my desk which are obviously way bigger than they should be, and an 8″ sub under my desk and I’m using the Floureon DLX360S. I am not sure the S is necessary, but for the cost of upgrade compared to what I have spent it’s nothing. I even have an AccuRemote I can send you, you can keep it if you want to try that one out. Should confirm your existing one, or perhaps they are both bunk.
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Graphite, I’m going to interact in this current thread with you. I have to say I’m sorry, but for me this has become tedious. Our minds and thought processes are way different. For me the “bottom line” of the Forum is I’m trying to help new and inexperienced WEPS users, and maybe experienced users too, to use their systems to sharpen their edges, just as those others before me graciously shared their experiences and knowledge with me.
Your insight and though processes are way beyond mine. You consider things I’d never consider to be of relevance. Neither of us is right or wrong. We’re just wired way differently.
This is my last hoorah. In the paragraph:
But your question gets me thinking, while that coarse/fine logging will work when I’m trying to replicate the exact angle for using same stones I used before, I’ll really need to use an angle cube if I change to stones of a different thickness from one sharpening to another. In that case I’d need an absolute angle reference, not just a relative one. So a properly functioning angle cube would be the tool for the job. BTW, I previously mentioned my angle cube repeatability issues and that I haven’t been relying on it. My Wixey cube uses what they call “Dead Level” and they claim it is “permanently calibrated at the factory and should never need re-set.”
I have to beg to differ with your thinking or maybe it’s your terminology here because I do want the “relative angle” not the absolute angle. I want the ability to zero out my Wicked Edge so the vice mounted to it and the knife clamped in the vice are measured relative to the zeroed base. That way it doesn’t matter how level the floor is or the table is, or the earth is. All that matters is the angle difference between my clamped knife and the rod angle adjustment point as it’s attached to the WE vice, as it’s attached to the zeroed base it’s mounted on. This angle is relative to the center of the clamped knife and the two bevels I’m sharpening.
I used the Wixey for quite a while and swore by it. I even argued with Tom, (TCMeyer), over it’s ease of use and repeatability, and I still stand by that. I purchased the Floureon DXL360, to compare effectiveness after he praised it’s accuracy. I then bought the Flureon DXL360S because it’s stats state it’s even more accurate and repeatable and there was some conversation on this Forum about the need for a better Dual Axis Meter. All three work very well, when zeroed to my WEPS base, and give very repeatable results of the “relative angle” I sharpen my knives to. Knives I sharpened with the Wixey and the DXL360 when mounted with my logged mounting settings are sharpening dead on the bevel, for me, now using the DXL360s. That is simply all that matters.
I’m going to keep trying to do things simple and uncomplicated. Please keep doing what your doing. It seems it’s working for you. Maybe down the road we’ll meet some where in the middle. Right now, my forum friend, I can’t keep up with you. My brain hurts. I’m bowing out.
Marc
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Hi Marc, not to worry. I’ve thought the very same thing in some of our exchanges, and just as you said, our brains are just wired very differently. I still value your inputs, whether you like it or not ;o) Yes I think it’s just terminology, since I don’t fundamentally disagree with what you described. I think it’s a case where if you were sitting right here next to me, by showing you the process I was attempting to describe (obviously not very well) it would all click. But as a written description it’s a challenge since the English language lacks enough word diversity on some topics. Sorry for furthering not lessening the confusion, and that was certainly not my intent.
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1000 grit stone is IMO one of the finishing stones. I don’t consider it able to remove much metal. More it’s to smooth metal and remove previous scratches. To do a quick light touch-up.
If I understand what you wrote, you only used the 1000 grit stone? If that is the case, the 1000 grit isn’t real effective for profiling. Therefore it wouldn’t help you even out the uneven bevels without a lot of work over a long time. The profile, (i.e., shaping the bevels) and evening out their heights and evenness is done with lower grit, coarser stones.
The resulting edge, working through the stone progression from coarse to fine, should improve with proper technique.
Finally, stropping the edge at the end really improves it’s paper cutting ability and removes the snags.
(EDIT): This I added later. You may have a plan when your starting, that maybe you can begin with a fine grit and thinking it may only require a touch-up. You need to be prepared to adapt. If you don’t get the expected results. Then I’d start stepping back down to coarser grits, stone and by stone and grit till you start to get the results wanted. At that point start the progression back up the grits to finishing stones.
Marc
(MarcH's Rack-Its)On using the microscope with every sharpening, do you guys with significant WE experience feel that if your microscope broke, you’d probably get mediocre (or at least, less consistently excellent) results without it? In other words, do you consider the microscope a truly essential part of your process toward getting excellent not just OK results?
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Edge leading is down and onto the clamped knife meeting the edge first. It is the same analogy as with free hand stones just now the knife is clamped stationary and your moving the stone down onto the edge.
Edge trailing is up and off from the heel or spine up towards the tip then off.
The scrubbing is a utility stroke both up and down over and over the same place then slightly, moved down, and then done similarly to another section, then spread out and blended together at the end, using overlapping strokes. The stroke direction I use is mostly perpendicular to the edge. Not diagonal. The purpose is to get the bevels, both sides, uniform shaped and similarly sized, (along the one side and side to side also). I’m trying to lay down even spaced parallel scratches of the same size and depth along both sides bevels, while creating even size and shaped bevels.
It’s hard to get a good even sharp edge only using one grit on a never sharpened knife. If you were doing a touch-up of a knife you had previously sharpened with the full progression then I guess a one stone one grit touch-up might bring back the initial sharpness. But in your situation who knows what you had to start with. You took a guess based on how it looked under a microscope.
You’re getting what you got because you chose to work with it. You probably could keep at it with the 1000 grit and improve the sharpness by doing more strokes. But it’s hard to do that while not changing the tiny bevels you wanted to keep that way.
To get better than acceptable edges you’ll need to sharpen that knife.
For me the microscope is now an essential tool. But since gaining experience while using it. I believe I know how to get just as sharp results with out it.
Marc
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