Messages

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the KJ-123 is a giant step ahead of the Anglemaster for setting knife bevel angles.
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Exactly.

Yup, and at a very good price point, I must say. Seeing how much they bill for a rubber mat, I was a bit worried to KS-123 would be in the USD 100+ range. Far from it

I do like to be able to set the angle to within about half a degree.  Why?  Because then I know exactly how to set my WS with blade grinder attachment to deburr the blade after sharpening, and at least as importantly, how to set it to strop the knife in between sharpenings. 

Given the precision of the WSKTS blade grinding attachement angle setting, I'm not sure one can get the .5° precision you mention. The slackness of the belt even on the tightest position is enough to change the angle by more than this. So if you set it to the same angle as the WS, you're probably at a higher angle where the belt meets the APEX. Which is fine for deburring and stropping.

Given this the JS should provide a more resilient edge. Having said that it depends on what you are using the edge for and how much extra work is involved. Yes, the SJ will give you a sharper more durable edge but whether that is what you want depends on what you are doing with the edge.

I thinks that's a very important part of what we're trying to do with a Tormek. For kitchen work where the blade works mostly in the direction perpendicular to the cut, I found that a polished edge that's initially "BESS-sharper" than one sharpened only on the SG will eventually feel dull faster.

If you're leaning on the geeky side of sharpening, this article along with this one on the scienceofsharp website are very interesting.

And I can't help but throw in this one as well that talks about burrs.

TLDR: The SJ will make for a very nice-looking bevel. But it will not really translate in better day-to-day performance.

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I'm 78 and not and not nearly as quick as I once was.
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Yes, I know that, I'm 84 and experience it every day 

As one of my favorite Star Wars characters once put it : "I may not be as young as I once was, but I'm older."

If you'll notice prior to locking the legs down you can rock the USB back and forth (not much but a little bit.)  If you push down on over the Micro Adjust leg and then secure it, you can rock (tilt) the USB up slightly with a bit of pressure.  But if you lock it down while pushing on the other leg, it can't move anymore. 

Strange. I just tried : push down on the USB on the MA leg, tighten the MA leg, tighten the non-MA leg, release downwards pressure on the MA leg. The USB cannot move *at all*. Or at least that I can measure...

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- wrong tightening technique for USB legs (one should press down on the leg with the MicroAdjust, tighten, then tighten the other one)

I'm glad you brought this up.  I know this is what Tormek recommends, but I now do the opposite, I push down on the other leg first.  The reason is I found that, for example, the Truing Tool which pushes up against the USB... if I push down on the MicroAdjust side first, the TT can push up and cause the USB to tip (enough that I can turn the MicroAdjust almost .5mm).  But, if I push down on the opposite side first, it's locked in place and won't move.  Obviously, I could tighten things down enough so that it doesn't matter (and of course light passes), just one more thing I don't have to think about.

Probably doesn't make a difference in reality (but if someone is measuring to 0.0015", it might.)

What'd ya think?

I'm not sure I follow you there. You mean if you tighten the leg with the MA then the leg without it, the TT can afterwards push up the USB legs ? I have not noticed this. I would rather be afraid of the USB being no longer parallel with the wheel shaft as there is no planar reference on the leg without the USB... I'll have to look into that.

I managed to get the wheel true and remove th 0.0015" gap, but having problem with getting a square edge on my 2 1/4" plane blade

If you wheel is true and parallel to the USB, it is now a matter of setting up your tool and blade properly. I'll be assuming you're using the SE-77 jig.

The blade can be out-of-square with the jig. It is unlikely that you'd set it up improperly against the near-side stops of the jig.

There are however two knobs on the SE-77 that are here to allow for camber as well as correcting for a non-straight angle. As per the manual, the two lines should be aligned for the jig to be in the neutral position, and both adjustment screws tightened. Loosening one and tightening the other allows for a slight skew, loosening both allow for a camber.

So you could check that after aligning both lines and tightening both screws, your blade is square to the jig. If it is, and the wheel is true and square, the last thing I can think of is technique, where you'd be applying uneven pressure on both sides of the blade.

Yup, as mentioned in several other posts, the "aligning against the side" tip works only if the USB is square to the side of the wheel. That has to be checked first.

It is square (within my measurements tolerances at least) on both of my T8s. The main reasons I can see for that not being the case are :
- bent USB
- wrong tightening technique for USB legs (one should press down on the leg with the MicroAdjust, tighten, then tighten the other one)

Nice !

Maybe with a "spaceship-type" contraption, we could do controlled honing on such a wheel.

This knife would micro chip, no matter what method or stone used.
With the T8 I finally got the micro chips out and back to a factory edge, while at the same time causing a hollow grind in the middle section.....grrhh. 
Lots more practise needed.....

For the carving knife, the steel might be quite brittle and will hate the kind of lateral impact with a hard stone it gets with the edge pro. The T8 edge leading, along with the finely controlled way you lay down the jig, will minimize this phenomenon.

As for the hollow grind, it is a very common problem at first. The most useful advice I could find so far are :
- Put a bit more pressure when the heel is on the stone to compensate for the fact that it will see less stone time overall compared to the middle section (in a video by Wootz)
- Round the shoulders of the stone significantly. Else when you lay down your knife, if it is ever so slightly tilted towards the tip, it will severely overgrind the middle portion.
- As you said, practice, practice, practice.

[Damn I messed up with the edits/post buttons]

I sharpened the same knife this a.m. on a SB stone (edge leading)... and while I didn't spend a lot of time on it, I'm pretty sure I got a better edge... at least slicing thru some ad paper.

I don't know much about the physical properties of SG and SB. But I haven't yet had to true the SB, and in its current state I would say the surface is more even than the surface of my (several-times-trued) SG. Ie the RMS height of the indentations is smaller. So you are using a harder, smoother medium than the SG, and it is logical that the blade would chip less. If you are abrading rather than microchipping on a smaller scale remains to be seen, and will depend on the relative hardness of this ceramic and silicon carbide.

I sharpened the same knife this a.m. on a SB stone (edge leading)... and while I didn't spend a lot of time on it, I'm pretty sure I got a better edge... at least slicing thru some ad paper.

I don't know much about the physical properties of SG and SB. But I haven't yet had to true the SB, and in its current state I would say the surface is more even than the surface of my (several-times-trued) SG. Ie the RMS of the indentations is smaller. So you are using a harder, smoother medium than the SG, and it is logical that the blade would chip less. If you are abrading rather than microchipping on a smaller scale remains to be seen, and will depend on the relative hardness of this ceramic and silicon carbide.

That's a fair point, but remember you need to compare apples to apples. You should compare the time it takes to sharpen with the T-8 with the time required to get the same finish on an edgepro. If you want to compare based on the Edge pro with glass stones and polish tapes (and I would add leather strop to really deburr cleanly) you should compare it to the Wootz version of the T-8, with the addition of the japanese stone and 3 different stropping compounds.

Two remarks AFAIAC :
- The difference between a T8 and edge pro is bigger as the blade gets longer.
- The mirror polish hair splitting finish you get when finely polishing the blade does not translate in kitchen-world edge retention and perceived cutting performance. A SG with honing on leather wheel is sufficient for most applications, as is the Edge Pro with the 600 stone and leather strop.

TL/DR : it's normal, and don't try sharpening your expensive knife with a SG even graded fine.

Don't know if that's what you mean, but those are two very different fracturation modes : tensile stress and compressive stress (hopefully those are the english terms, and to be precise there is also the notion of shearing). A given material can be fairly resistant to one and not the other.

If that given ceramic (or cement or whatever that knife is actually made of) exhibits the same kind of behavior as - say - concrete, it will be quite resistant to compressive stress (so you can stomp on it or try to crush it). But it will not resist to tensile stress, so you can't pull on it or bend it without breaking it. If you sharpen edge-leading, you will be more in  the compressive domain, if you sharpen edge-trailing you will be more in the tensile domain. 

The wheel substrate doesn't need to be too hard to chip the blade, it just need to be able to transfer energy to the blade. You can break a diamond chip with a screwdriver, or your precious ceramic knife on the edge of a hard plastic cutting board, if you hit sideways hard enough.

Steel usually has a very different behavior (and sharpening steel is an abrasion phenomenon, not a fracturation phenomenon). Brittle steel can be susceptible to chipping, as many of us know, but sharpening brittle steel still isn't the same as microchipping it.

The behavior experienced by @cbwx is consistent with a material that is less resistant to tension as it is to compression, but this is still a fracturation phenomenon. The chips we see, even though smaller in the edge-leading case, are still evidence of fracturation. You're doing something more akin to making a knife out of silex (the stoneage way) than out of steel. I would not call that sharpening unless done with a very hard, very fine (diamond ?) substrate, that will abrade the material instead of chipping it however microscopically. A rough, hard substrate may lead to fracturation instead of abrasion. That can be computed given the rotation speed of the wheel, applied pressure, angle, maximum particle size and a few physical constants describing the blade material.

One of the most valuable pieces of advice I found in Tormek's videos was about how to avoid overgrinding the middle by thoroughly roundoing out the shoulders of the stone.

Tormek support continues to hold up to their top-notch reputation.

There's no difference in using the KJ vs the SVM jig to set up the KS-123.

BTW, for a bit of trivia, the KS handles a Projection Distance of 122-158 mm.

I understand that ^^

I might not have been clear enough : I was thinking of how when you set the whole thingamajig up with a given protrusion distance, and you want to use the adjustability of the SVM to setup another knife for the same sharpening angle. Ie not adjust the jig to the second knife then adjust USB, but rather use the SVM handle to adjust the protrusion distance to match that of the first knife without touching the USB. Does it make sense ?