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Thank you for this instructive response Nick!.
My comparison also fails, because a knife is not hollow, as you explained very clearly.
I am also going to study your link

Wim

Ken,

That is also the main reason for me to purchase the BESS tester. Of course, I was also curious about where I stand with my grinding.
But I notice that my customers also find it special to see how sharp their knives are. Although they do not see the relativity of a measurement.
("Can you sharpen my knife again at 88 BESS," a customer asked me .

Here is a link to one of his videos, in which he propounds a theory in support of the superior toughness of a convex edge.

https://www.youtube.com/watch?v=XA5AM2Lb0iY&ab_channel=virtuovice

When I see the decomposition of forces at a convex ground blade, it reminds me of masonry pointed arches of churches.

In itself, there is some truth in that, and certainly an interesting thought.  But whether that is substantially noticeable in practice, I wonder. To my senses, it seems to me that a convex ground blade is more likely to "slip" over the material being cut.
But I say that as a woodworker, where you can't use convex-sharpened chisels very well.

I do say that I have no experience with this type of knife.

Yes, this kind of ticket I mean.

So they can't be ordered as a product of BESS Edge-on-up. Then I will design and print them myself.

Thanks!

Today I also got an Edge-on-up BESS meter. I have a couple of question about that:

I see on YT videos when using the BESS Edge-on-up cards, writing down the measured value before and after grinding. Are these cards for sale?
(I can't find it on the internet)

I am happy with this measuring tool, because now I can see for the first time, which grinding results I have achieved (in a number of measurements it varied from 45 to 130 BESS)

" I want to use a jig for honing because the freehand method is too erratic and imprecise."

I have personally observed an expert Tormek sharpener precisely hone knives and chisels freehand, as well as watching Wolfgang do the same in the online class videos. Their skill did not happen overnight. I am not opposed to using FVBs; I have actually purchased two of them. (They have other uses in set ups.) However, I believe you short circuit your sharpening if you do not master freehand honing.

Ken

There is something to that. When I learned to sharpen chisels 52 years ago, we were not allowed to use an attachment. It had to be freehand.

Not because it was better, but to train a steady hand.
So in our carpentry textbook was the phrase, "it is the craftsman's honor to do it without attachments." Expensive words that we as adolescents did not understand

Martin,

I really enjoy situations where everybody wins, everyone benefits. Your happy situation is certainly one of them. The students and school benefitted; you as both sharpener and teacher benefitted. And, the walnut table you will build will be a happy reminder of this enjoyable time.

Well done!

Ken

I totally agree with that.

Wim

Adam,

I am a fan of precision, not accuracy (https://www.diffen.com/difference/Accuracy_vs_Precision).  The Tormek is an excellent tool for repeatability and that is far more important to me as I resharpen often.

In his review of Simon Winchester's The Perfectionists: How Precision Engineers Created the Modern World, James Gleick writes for the New York Review of Books... precision involves an ideal of meticulousness and consistency, while accuracy implies real-world truth. When a sharpshooter fires at a target, if the bullets strike close together—clustered, rather than spread out—that is precise shooting. But the shots are only accurate if they hit the bull's eye. A clock is precise when it marks the seconds exactly and unvaryingly but may still be inaccurate if it shows the wrong time.

To me, the exactness of an angle is less important than that is always the same and I can count on that. 

Rich

That is a beautiful thought. My first carpentry teacher told me 52 years ago in the subject of tool learning: "the first 89 degrees you do with your square and the last degree you do with your eye".

I didn't understand it then, but I did later:
Don't just rely on your measuring tools, however good they may be. Think carefully about what and how you measure and accept that practice will always be different.

It is a mass grinding process.  How would I go about it?

I would first study the status of the chisels carefully. At what angle are most chisels sharpened? Do you maintain this angle or not. (In the Netherlands, we sharpen chisels at 27 degrees instead of 25 degrees). How flat and polished is the back? That is where most of the work is. If the back surface is too damaged, I would not sharpen that chisel. That takes a lot of time.

If you want to change the sharpening angle, it takes more time than if you maintain the angle.

I would also not go for a "secondery bevel". This only slows down the overall grinding process and does not yield much profit (it is never used in the Netherlands).

Furthermore, I would start with the 19mm width chisels. That is the chisel I have used the most in the last 50 years and it is the same for most woodworkers.

I also agree with Ken: Leave out the Japanese stone. It doesn't give much sharpening result for chisels. Use the Sg-250 or the Diamondstone 600 and then the leather wheel with the Tormek paste.

Don't forget that these are apprentices. They also have to learn, while working with a chisel, to regularly take the chisel over a whetstone and then work with the chisel again. That's why I always had a Belgian Coticule-stone in the pocket of my overalls.....

Wim,

Bravo! You are on the right track. I have never understood the reasoning for using the frame as the measuring reference point instead of measuring directly from the wheel. Guided by Dutchman's grinding angles booklet, I have used Dutchman's direct to the wheel method for eight years with my kenjig. No compensation is needed when switching from the T7 to the T8. Using Dutchman's tables with diameter changes, the direct measuring with kenjig works with no modification with the T4.

Borrowing Wim's depth gage idea, the kenjig could be modified to eliminate the need to purchase a depth gage. Shorten the slot to around one inch. Mark the kenjig with the Distance. You will need to make up several kenjigs with different Distances.

With the KJ-45, there is easily a range of 10mm. Using CB's Calcapp, enter Projection values from your widest to your narrowest knives. Note these values and use them to make up kenjigs. These kenjigs will be gage blocks, having the same measurement year in and year out with no need of resetting. The Projection could be adjusted match one of the kenjig Distances.

Kenjig instructions are posted on Rich Colvin's Sharpening Handbook.

Ken

Ken,

Thank you.
By measuring on the FVB, you have to measure very accurately, to tenths of millimetres and the exact 90 degrees of a carpenter's square. Otherwise the setting will be imprecise.

But the risk is that you can get lost in an idea of accuracy that is not realistic for the grinding process.
The tools' calculations encourage this line of thinking, as they (understandably) calculate to 2 decimal places.

To be clear, I have a lot of sympathy for the developers of the calculation models. Please continue to do so.

Wim

I have used both the KG software and the TormekCalc and also tested to measure on the FVB. For this I took very accurate measurements, with also accurate large squere, with a guaranteed 90 degree angle.
I have also sharpened a knife on those values based on the settings I found.

In the end I find measuring the USB directly on the wheel the most accurate method.  This can be done with the TormekCalc, but also with the tool of cbwx34. The results of the calculation are the same.

This measurement is:
- Accurate, because you are least affected by possible multiple measurement deviations, which you have to set. This includes not only distance measurements, but also 90-degree angles.

- Simple, because it does not matter which FVB you use. Only the distance to the wheel counts.

I did adapt the depth gauge slightly, to hit the wheel at the right place. See photo's.

I really appreciate your input Rick!

Something similar was also my idea and I too am following KG on this.

And also your comment about using different water for the SJ-250. Top!
I also like the use of a coffee filter.

Wim

Thank you.

I notice that there is no "wow" feeling in response to my question about honing with a JDS-250.
I think a mirrored cutting edge is more likely to suggest that a knife or chisel is very sharp, but I don't read anywhere that is actually always the case.

(For woodworking, a mirrored back surface is not that essential. I have been working with chisels since 1970 and have never seen mirrored back surfaces in practice.
For a chisel, however, it is important that the back surface be free of pits. Otherwise a chisel will never be sharp. The extra honing time you spend on this does lead to mirrored back surfaces. But pitting on the back of a chisel can be easily prevented, by not leaving it outside for a long time and not in humid areas).

Thanks for your response Nick,

My considerations for an SJ is to be able to make the routine shorter, but I don't read anywhere that this actually happens.
On its own, an SJ-250 is expensive (In the Netherlands $300). But a Rockhard Feltwheel also costs money. Especially if with a certain regularity diamond paste should be applied.

Surely a light form of honing is necessary.
The only 'real' benefit so far is that the cutting edge looks nice and mirror-like.

You do have a point regarding the fluid. There is always some residual metal in there. So a separate water tank for the SJ might be better.

Wim

I am considering purchasing the Japanese grinding wheel the SJ-250. I have two questions about that:

1) Who has examples of grinding routines when using the SJ-250. This is not about the sharpening part (which I do with the diamond stones), but about honing process. Or is honing just redundant?

2) I am using the diamond stones with the water to which the anti-rust concentrate has been added. Can I also use this mixture for the SJ-250?  Or does it have to be pure water?

Thanks in advance for the answers

Wim