Venev Cenaur diamond dual sided stone issue

[3D Anvil]

For uneven bevels, if you do worry about them a little, I think the best solution in most cases is to work the side with the narrow bevel more than the wide side. Apex the blade on the skinny side and then keep working it to start evening out the bevel width. Don't try to do it all in one sharpening. You can even it out over the course of 2 or 3 sharpenings.

 

[CplMurdock]

The uneven bevel I’m referring to is not from side to side, but exist on a single side of the blade as if you are trying to sharpen a convex edged blade on a fixed system without the angled attachment. My apex is centered within the blade and is not the issue.

Think about only one side of the blade. If the stone you are using is thicker on one end than the other, you end up with an ever so slight convex edge (with the thickest part of the stone furthest away from the pivot point). If the next stone you use, has a different “angle” due to being either straight, less, or more, angled than the previous stone, it will not contact the bevel the same, and in some places won’t touch the bevel at all. Yes, the convex edge is extremely slight in this case, but it exists.

 

[crn3371]

Here’s a quote from part of a response I got in that thread,
“For a blade sharpened at 15 degrees per side, vs 16 degrees per side (assuming as an example a thickness behind the edge of 0.2 inch), the difference in edge bevel length will only be 0.0023 inch. That's about the diameter of a strand of hair. Obviously not perceptible with the naked eye.”

 

[CplMurdock]

Here’s a quote from part of a response I got in that thread,
“For a blade sharpened at 15 degrees per side, vs 16 degrees per side (assuming as an example a thickness behind the edge of 0.2 inch), the difference in edge bevel length will only be 0.0023 inch. That's about the diameter of a strand of hair. Obviously not perceptible with the naked eye.”

The unevenness of the bevel that I am describing is not at all a “side to side” issue. The bevel lengths are not my concern at all.

 

[crn3371]

It was meant to show that minute changes in stone angle don’t make much difference.

 

[CplMurdock]

It was meant to show that minute changes in stone angle don’t make much difference.

I completely agree that “side to side” a one degree change in bevel won’t make any real difference. However, read in post #4 where diemaker talks about looking at bevels under a microscope and how, when changing stones, on the same side of the blade, a .02” change in thickness of the stone can mean only polishing half of the bevel unless the change in thickness is compensated for. This is exactly what I am experiencing. The variance in stone shape and size is causing only a portion of the bevel to be polished by the next grit of stone unless I spend time adjusting between each stone. I don’t have to adjust side to side when keeping the stone the same, only when changing stones during the progression.

 

[777 Edge]

With any and every stone brand or type - doesn't matter who makes it or where it's from, I would recommend getting into the habit of using your angle cube to readjust your angle each and every time you swap stones. For consistency, measure it on the same side of your blade, in the same spot on the stone and blade.

Even if your stones are 100% the same thickness when new (which hardly any stones are), invariably they will start to change in thickness with use. Your coarse stones (doing the bulk of the work on new knives and bevel setting) will wear down a little faster than the rest, so they will narrow out with time. It's also a good habit to use an angle cube every time you change a stone, so you can mix and match stone types, brands and sizes while you experiment and sharpen.

The Geometry mentioned above was from my explanation on bevel length for 1 degree angle difference, it's not related to this thread because we are talking here about changes in angle on the same bevel side, between stone ends. That could effectively make a difference, depending on some factors.

We also spoke about geometry in another thread that was relating to very slight dishing of stones, but that discussion relates to very slight variations from one end to the other on the same stone. Depending on the stone variations, your sharpening pressure and time spent on each stone will have much more effect on your bevels than tiny inconsistencies. That being said, if you have 0.6mm difference in stone thickness from one end to the other on the same stone, it could possibly make 1-2 degrees difference in contact angle on your blade (depending on the arm length from your stone rod pivot point to the contact point on your knife.)

The Venev stones are phenomenal stones for the money, and they will give you excellent edges. If the tiny change in thickness from one side to the other of your 1200/1500 bothers you or makes a significant difference, then it's very quick and easy to even it out with some silicon carbide. I would not do too much if I were you, because you'll just be wasting away good stone surface, but it's easily doable if you need to. Just be careful not to do too much.

 

[CplMurdock]

777 Edge, Thank you for taking the time to comment. I think I’ve read through all of your posts about these stones, and the sharpening systems they work with. I also find the work you have done with 3D printed systems to be fascinating. For what these stones cost, I am generally happy with them but I know that the final result can be quite a bit better than what I am currently getting due to the angle changes. Yes the differences are small but I think that since this set was fairly inexpensive I might try using the sic to get them somewhat closer to each other in size and see what happens. In the future I will probably be picking up a set of Venev Orions since I prefer the 1x6 edge pro style mounting system.

 

[sickpuppy1]

Or better yet, the Matrix stones.

 

[CplMurdock]

Or better yet, the Matrix stones.

For some reason, and I’m not sure why, but the idea of trailing strokes only just seems strange to my brain and muscle memory. I’m sure that after a while they would feel normal but I tried spending half an hour using my current stones trailing edge strokes only and it never felt right. I guess that and the added cost of the matrix stones makes me hesitant to get them. The reviews I read though makes me kinda want to try them.

 

[sickpuppy1]

You dont HAVE to do trailing strokes and I have no signs of damage or anything but you seem to get a smoother scratch pattern that way is all. I generally use both ways when I'm working a blade with damage or setting a angle for the blade and do trailing strokes from 650 on up. That for me is because I've done all the major shaping to the steel already and am now refining the apex.
Again, you dont have to to trailing only, but it gives a cleaner looking edge. On my daily use pocket knives I am looking for a toothier edge as I cut boxes open, zip ties and the like as a maintenance tech so I stop at 650 and then strop. If I want a slicer edge I go to 1000 and 2500 and strop. This is just the way that works for me and your mileage may vary.
On these stones I rinse an wipe them off with a paper towel after use and about every 5-6 knives I take em to the sink and use toothbrush and dawn to clean the pores out so to speak. About 30-35 knives I use some 240 grit sic power and water on a 12x12 sheet of glass to renew the stone. about 6 figure 8's and its done. I've had mine for almost 2 years and no appreciable wear as yet. That to me is cost effective, so the initial purchase price is warranted. Not everyone is going to have same results and I learned b4 I bought them that it take much less pressure than you realize to get the results desired because of the stone make up. I also have a couple of Venev single side stone and like them almost as much, but I like the feedback I get thru the Matrix stones better. I verify thru a jewelers glass that I'm done, but I can feel the smoothness when pulling the rod.
No matter what stones you end up with, if you pay attention to the feel it will tell you alot when you are sharpening. You can feel the uneven waves on an edge. you cant feel a chip of course, but light passes tell you stuff that a heavy push or pull wont.

 

[777 Edge]

For some reason, and I’m not sure why, but the idea of trailing strokes only just seems strange to my brain and muscle memory. I’m sure that after a while they would feel normal but I tried spending half an hour using my current stones trailing edge strokes only and it never felt right. I guess that and the added cost of the matrix stones makes me hesitant to get them. The reviews I read though makes me kinda want to try them.

You'll have no issues using the Venev stones edge leading, trailing or any way you prefer. I use mine leading and trailing strokes, back and forth. I only switch to edge trailing strokes for my last couple strokes each side on my fine stones, just before stropping.

I also use my Matrix stones the same way with no issues.

If you do decide to lap yours down with Sic, don't go all the way to trying to make all 3 stones exactly the same thickness, only lap them enough to have even thickness on both ends of your stones. Just make sure to use your angle cube and adjust every time you swap stones.

Another "trick" you could try (if you didn't want to lap them down), is rotating each stone so that the slightly "thicker" side of each stone is closest to your sharpening hand (the hand holding the stone holder rod.) This will give you a very very slight micro convexed edge, and it should then help you to cover the whole edge bevel when sharpening. If the "thicker" side of the stone is furthest away from your sharpening hand (closest to the sharpener pivot rod) then you won't cover the whole edge bevel. This will effectively "concave" sharpen your edge and thereby only grind away the back part of the edge bevel, missing the very apex of the edge altogether.

All that said, we are still only talking very minute variations here.

 

[CplMurdock]

Another "trick" you could try (if you didn't want to lap them down), is rotating each stone so that the slightly "thicker" side of each stone is closest to your sharpening hand (the hand holding the stone holder rod.) This will give you a very very slight micro convexed edge, and it should then help you to cover the whole edge bevel when sharpening. If the "thicker" side of the stone is furthest away from your sharpening hand (closest to the sharpener pivot rod) then you won't cover the whole edge bevel. This will effectively "concave" sharpen your edge and thereby only grind away the back part of the edge bevel, missing the very apex of the edge altogether.

This is exactly how I’ve been using them for the last couple days. I marked the thicker ends and have been keeping them closest to my sharpening hand. I’ve definitely seen better results this way. I will be adding more stone sets to my collection. With any hobby, there is always something else to try And these new stones are such a change from the first time I tried making a piece of metal sharp thirty some odd years ago.

Thank you to everyone who has taken the time to respond here. I am going to order the edge pro glass and some sic powder to see what happens. I’m also going to do a bit more reading and order another set of stones after the holidays.

Merry Christmas everyone!

 

[777 Edge]

This is exactly how I’ve been using them for the last couple days. I marked the thicker ends and have been keeping them closest to my sharpening hand. I’ve definitely seen better results this way. I will be adding more stone sets to my collection. With any hobby, there is always something else to try And these new stones are such a change from the first time I tried making a piece of metal sharp thirty some odd years ago.

Thank you to everyone who has taken the time to respond here. I am going to order the edge pro glass and some sic powder to see what happens. I’m also going to do a bit more reading and order another set of stones after the holidays.

Merry Christmas everyone!

My pleasure, and have a happy, merry and blessed Christmas too.

 

[777 Edge]

The Venev Centaurs on Gritomatic are
- 80/140
- 240/400
- 800/1200

Did you write down the wrong grits or you have a different set?

The grit numbers are correct, Gritomatic now also has a 1200/1500 combination Venev for sale.

 

[777 Edge]

Matching ends won't make any difference, they will still contact the bevel the same distance from the pivot no matter which orientation they are mounted in.

Not correct, using the thicker side of a stone closest to your sharpening hand will help, and give you a slight convex edge.

This is the way I designed my convex sharpening accessory for my Leading Edge sharpening system. My convex sharpening accessory stone holder lowers the stone closest to your hand (similar to a thicker side of a stone closest to your hand), and this gives a convex edge.

 

[Diemaker]

Not correct, using the thicker side of a stone closest to your sharpening hand will help, and give you a slight convex edge.

This is the way I designed my convex sharpening accessory for my Leading Edge sharpening system. My convex sharpening accessory stone holder lowers the stone closest to your hand (similar to a thicker side of a stone closest to your hand), and this gives a convex edge.

I stand corrected. Upon further thought, if .02" over 8" is enough to cause major trouble then .01", .26mm, over 4" will do the same. I trigged the angle for .01", .26mm, over 4" and got .14166 degrees so it should be enough to measure with a decent angle cube.

Here is the image of what a .02" difference in stone thickness will do on a guided sharpener with 8" between the pivot and the bevel. This was taken in June 2018 so my memory isn't going to be perfect, but I think the bevel was about .05" wide on a Henckels knife so the SG stones work quite well with this steel. I do remember the finer stone was thicker and I only made a few passes, but it would have been enough if the stones were the same thickness. As you can see it will take quite a few extra passes because of the mismatch in stone thickness. Sure it can be done but it will significantly increase how long it takes to sharpen this knife, if it is caught while doing so. This was either the 4000 to 6000 jump or 6000 to 8000.

This is why I think repeatability is paramount when using guided sharpeners, and especially the current designs. I don't like clamp systems. It takes very little flex to cause this mismatch just like the difference in stone thicknesses. As for using an angle cube to compensate for different stones, .1 degrees over 8" will give you .014" of movement, as in difference in stone thickness. This is the standard precision of normal angle cubes so it really is too coarse. A mechanical compensator should be accurate to .001" to .002", so obviously they are far better than an angle cube for compensating for different stone thicknesses. I know this is kind of rabbit hole territory but as the image shows it does make a noticeable difference.

Once past my coarsest stone I use approximately 3 passes per inch of blade length per grit, any more does not improve the polish. How many passes does everybody else use?

 

[scottc3]

Low resolution me has enjoyed reading plenty on this variable, and others, across blade geometries, differing components, systems, etc, but my experience is mostly even bevels. If a bevel, or more commonly across bevels, is uneven to my eye, I look for the problem to solve it. And blade wear can be your friend for ironing out differences sometimes. All our knives down to the grand kids with one exception... which TSA now owns, are production / machine made, so compensating on a reprofile must include a keen eye.
My mind came to the conclusion that bevel variations as a result of angling variations across freehand strokes in a commercial finish / restaurant meat cutting setting might be as much as 5 degrees on a set of Case knives, and still result in sharp edges a long time ago. From memory, with the KME and a bunch of stones, measurements with a phone App demonstrated consistency to 1 or so degrees results in sharp edges.

This is the way I designed my convex sharpening accessory for my Leading Edge sharpening system. My convex sharpening accessory stone holder lowers the stone closest to your hand (similar to a thicker side of a stone closest to your hand), and this gives a convex edge.

Brilliant to observe convex shape by stone's thickness via orientation to design stone holder 777 Edge. Gotta use that to explain convexity of bevels with convex rods, belts n stone holders now!

 

[Bob9466]

With any and every stone brand or type - doesn't matter who makes it or where it's from, I would recommend getting into the habit of using your angle cube to readjust your angle each and every time you swap stones. For consistency, measure it on the same side of your blade, in the same spot on the stone and blade.

Even if your stones are 100% the same thickness when new (which hardly any stones are), invariably they will start to change in thickness with use. Your coarse stones (doing the bulk of the work on new knives and bevel setting) will wear down a little faster than the rest, so they will narrow out with time. It's also a good habit to use an angle cube every time you change a stone, so you can mix and match stone types, brands and sizes while you experiment and sharpen.

The Geometry mentioned above was from my explanation on bevel length for 1 degree angle difference, it's not related to this thread because we are talking here about changes in angle on the same bevel side, between stone ends. That could effectively make a difference, depending on some factors.

We also spoke about geometry in another thread that was relating to very slight dishing of stones, but that discussion relates to very slight variations from one end to the other on the same stone. Depending on the stone variations, your sharpening pressure and time spent on each stone will have much more effect on your bevels than tiny inconsistencies. That being said, if you have 0.6mm difference in stone thickness from one end to the other on the same stone, it could possibly make 1-2 degrees difference in contact angle on your blade (depending on the arm length from your stone rod pivot point to the contact point on your knife.)

The Venev stones are phenomenal stones for the money, and they will give you excellent edges. If the tiny change in thickness from one side to the other of your 1200/1500 bothers you or makes a significant difference, then it's very quick and easy to even it out with some silicon carbide. I would not do too much if I were you, because you'll just be wasting away good stone surface, but it's easily doable if you need to. Just be careful not to do too much.

I agree. I have a full set of the centaurs. I use the angle cube and on occasion the angle compensator on both my hapstone and kme. Have consistently achieved excellent results.