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I'm sorry but I find the posts by @KaithyHong suspicious : newly registered user, some posts having nothing to do with the actual topic, links to an external website that's 26 days old and has nothing to do with a "smooth swivel plate" except that an AI could have confused the two.

Out of 7 posts, 5 start more or less the same and give a general advice. Out of all the new members of this forum, that's both the most educated and most unspecific one.

I advise caution.

One thing I'd add is to make sure the stone is properly trued and the support bar is firmly locked before making any adjustments. Small setup differences can have a bigger impact on the final result than most people expect.

I'm sorry, what ?

Then a solid option would be to contact Tormek support ([email protected]).

I don't believe the second knife (the one with the black handle) has been suddenly "eaten" by your T8. It has seen a lot of sharpening time before it went to a standard convex (or straight) shape to this concave shape.

The first one I can believe, and is a common problem with Tormek machines. It can be avoided with :
- careful technique (compensating by spending longer at the heel, not using too much pressure, ...)
- a few tips. Notably, the biggest improvement for me was rounding out the shoulders of the wheel after truing it. Too sharp corners will dig into the blade whenever the blade does not rest fully flat against the stone. Also, I always make sure to lay down the knife ever so slightly tilted so the heel hits the stone first and not the other way around. Of course you have to aim for flat, but better to err on the heel-first side rather than heel-last.

As for your wobble, is your video taken right after truing ? That would be odd. My bet would be that the stone has been trued, taken off, then put back on, but rotated. There has to be some clearance for the wheel to slide onto the shaft. So if you put it back in a position that's different from the one used for truing, then that will create some wobble (proportional to 1-cos(alpha_truing-alpha_sharpening) ). Standard practice is to always put the stone on the shaft "label up".

Also, please keep in mind that such wobble is unstable. Said otherwise : it will create a more uneven surface over time, especially if you use heavy pressure : the blade will kind of dig in each time it encounters a low spot, making it even lower. This is another reason to use reasonable pressure, and to often true  the wheel a little as opposed to seldom true it a lot. However, if every part of the blade sees the wheel a similar amount of time, the effect of this wobble will be homogeneous along the length of the blade and will not create dishing.

Hope this helps!

It will also show you when you've stropped too much.

Can you elaborate on this ? What are the effects of too much stropping ? Do you mean honing on the honing wheel ? What is your process ?

I have never experience such a thing as too much honing, but maybe it is because I haven't done enough testing...

I'd agree with Rick. I had not thought of using the USB real close to the wheel, it will definitely give welcome support, then some kind of a laser line can be used to keep the angle constantish.

The SVMs will not provide enough clearance : the handles will hit the USB.

I would give it a try freehand. Not much you can do aside from that.

My question is, if the KS123 is not satisfactory for high volume such as "weekend warrior" farmers market sharpeners, what is satisfactory?

The way I see it, a sharpener at a farmer's market will not reset the angle but rather reproduce the existing one using the sharpie method. If one wants to reset the angle to, say, manufacturer's specs then the KS-123 will do just fine but my gut feeling is it's not going to be the majority of cases.

When I'm talking about high volume sharpening, I'm thinking more of a "I want to sharpen these 10 knives @15dps". In that case, KJs, vernier calipers and a calculator/Dutchman's tables/a simple arccos+arcctan formula are a bliss.

Ken, you're right, I'll give it a shot.

TL/DR : 15 dps.

For a more detailed summary : most members recommend something in the 15-20dps range, with a majority grinding closer to 15dps. Setting this angle using the KS-123 is practical for low-volume sharpeners.

[follow the instructions]

As long as I follow the instructions and always start from a smaller angle when using the KS123 to approach the desired angle, I have no problem with precision.

Unfortunately that's not how friction works: once the static friction coefficient is no longer sufficient to keep the needle in place, it will switch to kinetic friction, and the needle will move as much as necessary to get back into the friction cone. Then stay in place, and here we go again. So while the error may always be on the same side, we have little control on where the needle stops.

As for a 160 grit stone raising a burr quickly, I have no doubt.

[measure]

When I hear concerns about using the KS-123 due to it being less than needed accuracy, I wonder why the angle on the blade must be accurate to 0.1°.  In the sharpening I do for most things, if the angle is good to +/- 1 degree I am good.  What am I missing?

Nothing.

I think this is an example of going to the extreme without any clear delineation of the benifit. When Wootz proposed some new idea he backed it up with extensive testing and real world usage in meat packing plants. I believe only a miniscule number of users have the ability to measure the angle to this accuracy.

If I may introduce a modicum of nuance and open-mindedness to "Nothing" :
- I agree being able to measure the edge angle with 0.1° precision has no benefit in terms of sharpness or edge retention
- However, being able to reproduce a given angle quickly with the smallest deviation possible results in raising a burr much faster, with less metal removal.

As we are talking small angles, the amount of metal being removed is proportional to the ratio of angles : you remove 5 times more metal if you're 1° off compared with .2° off. It is to me a clear delineation of the benefit. [EDIT] Actually, much more than this if you take into account cases where you will be thinning the blade [/EDIT]

There are two phenomena with hysteresis here :

- One linked to the threaded rods, which can be compensated by always ending with slightly raising the USB. This is standard operation and does not cause any issue. It will prevent the USB from settling lower due to the rod moving slightly insided the nut before getting fastened.

- Another one linked to friction inside the KS-123. Going down, then up, will ensure that the error is always on the same side. For a given static friction coefficient, that is, which will depend on when it was lubricated, if it is slightly wet or not, how tight the nut is, etc. Plus, the amplitude of USB movement necessary to put the needle back in motion on the way up is much, much higher than with vernier calipers resting against the top of the USB and the wheel where only the slightest turn of MicroAdjust nut is enought to lift the lower end of the wheel.

So while using the down-then-up routine will minimize the error, it will still be more important than using the distance method, less reproducible, and therefore the amount of material that needs to be removed before raising a burr will statistically increase.

the KS-123 has significant hysteresis

I have not noticed any.

Do you mean that says, one 8th of a turn on the MicroAdjust always results in the plastic needle moving on the KS-123 ? On mine, even after some lubrication, if I move the USB down, then up, I can change the angle by almost 3/4th of a degree before the needle starts moving up again. And I can move the needle up and down by hand, the flexibility and friction will let it stay wherever I put it within one degree.

[...] the KS-123, which has halted the growth of computer programs and all communication about it.

What a relief, more focus on the real work.

Wow, that's a tad judgmental. There are very good apps out there, and the KS-123 has significant hysteresis. Surely there is room for people who already own vernier calipers and are fine with using apps/spreadsheets ? Why the condescension ?

While I have occasionally experimented with 12°, based on Wootz' recommendation, 15° has remained my go to setting.

Same here. 12 dps is for a very specific subset of knives : suisin inox honyaki series knives whose steel is quite robust, or some of my high hardness knives. The problem with 12dps in my opinion is that although edge retention is usually better, the apex is prone to chipping. So it's only for knives that are going to be handled carefully.

As chipping is much less of an issue at 15dps, I feel this is the good compromise with good edge retention.

As a side note, when one is not concerned with initial efficiency, I find that a 10dps primary bevel with a 15dps secondary bevel works wonders as it allows for very quick touchups afterwards.