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At this point, I would like to suspend this conversation, leaving you with the last word. I want to do careful testing with my T2 and photograph the bevels. (With my family obligations this may not be speedy.) When I complete this testing, I will post the photos, regardless of which position they support. Is that agreeable with you?

Just out of curiosity, do you have any hands on experience with the T2?

Ken

Ken, this is fine. This reminds me of a line I read on another post :

i believe we have squeezed as much useful juice as this issue has to offer. Let's move on.

But it seems the OP in this more recent post has a different opinion and thinks it is important to revisit the firestorm. So revisit we do...

I have no hands on experience with the T2. However I have experience with a Trizor XV which works exactly the way the T2 works, or with the Ken Onion Sharpener in its original edition, along with enough math background to trust the fact that under reasonably applicable hypotheses to our knife sharpening situation :

sin a = ht / bl where a is the edgle angle (measured @ 90° from the edge) in dps, ht is half the thickness of the blade at the top of the edge and bl the bevel length.

So with an angle guide, a and sin a remain constant, so bl increases with ht. Or if ht increases and you want bl to remain constant, you have to increase sin a and therefore increase a.

Or as this non-Tormek related site puts it :

On knives where the tip is inline with the spine and where there is not a distal taper, the effect is more pronounced. A wider bevel in this circumstance is a purely cosmetic concern since the angle is constant.

Which I think is about the same thing I said, english mistakes aside.

There is also this site and many others.

As you said it too, the T2 is pivot only. The same causes will have the same effects, so you will get the same result as on the T8 if you pivot along the laser line instead of lifting. When you lift, you increase the edge angle and comparatively reduce the bevel height. But maybe I missed a key point...

Common steel does not get microchipped like ceramics do, in the same way that hitting a plastic bottle with a stone will not have the same result as with a glass bottle. Sure, you might end up with breaking the bottle in the end in both cases, but through different deformation/fracturation mechanisms. Which will also result in quite different particle sizes.

And to be fair some very hard steels tend to microchip too, but they're not the common lot of knife steels.

I think steel particles found in the trough after grinding on a fine-graded SG will be at least one order of magnitude smaller than what you're showing.

Dutchman, what side piece are you referring to ?

The particles seem quite coarse. So it looks more like the edge is somehow getting microchipped away. It would be interesting if you could somehow get a microscope shot of the edge and the particles.

I've just watched the video where Tormek demonstrate the use of the KS-123.

I don't know yet if I'm going to buy one, because I feel the calculator method serves me so well. Still it is quite appealing to dispense with measurements, especially the wheel diameter one. All in all, if I didn't have my vernier calipers already, the KS-123 would be the obvious choice. It is not very expensive.

A few comments on the video :
- I would have loved to have a vernier on the jig itself. Not necessarily to chase one tenth of a degree, but rather to improve the overall precision. Maybe they could just add a few markings on the composite needle plate that would help with centering on degrees or half degrees marks.
- It's quite funny to see them still struggling with their explanation that earlier methods (AngleMaster, uncontrolled honing, ...) were "not complex, but more complex" but really you should buy the KS-123 (and the MB-102).
- Couldn't the KS-123 also be used in combination with the sharpie trick to measure the edge angle of an unknown knife ?
- The fact that the KS-123 can be used with the SVM-00 assumes that it is easy to center the blade with respect to the plane of symmetry of the SVM-00. Spoiler alert: it is not. so using it the way it is demonstrated with a sloyd knife is a recipe for disaster: one will most certainly alter the edge angle of the knife and make it assymetrical. If you want to use the KS-123 with the SVM-00, you should take the time to center the blade first, with careful and repeated use of the sharpie trick. If it were easy, it would be demonstrated by Wolfgang in his video about the SVM-00. On the contrary, Wolfgang explains how to not center it.

I do take issue with your comment about the T2 being for customers who "don't care about bevel looks". Before composing this, I sharpened several kitchen knives with my T2. The bevels looked fine to me.

I understand why you may feel the way you do. The technique for the T2 differs significantly from our old standby technique for the T8s, etc. We were all taught to lift the knife rather than pivot. That works fine with a T8, but not with the T2. Different does not necessarily mean better or worse.

Ken, this is not a question of how I feel or how the edge of a particular knife looks. This is a question of geometry : the T2 is a constant angle sharpener, so if the thickness at the tip of the knife differs from what it is along the flat or belly of the knife, then the bevel width *will* vary. In this respect, the T2 will have the same problems encountered by those who who use a Trizor XV, or who pivot without lifting on a Tormek using the laser line: some (many) bevels will get wider, some (a few) will get narrower. And of course some (in between) won't vary. However the sharpener has no control over this.
And I didn't say this was necessarily worse : some will prefer to maintain a constant angle at the expense of looks because the blade cuts consistently from tip to heel. For knives that get thicker though, it will require accepting the difference in looks *and* heavy grinding the first time to reshape the tip. Again, no choice.

I sharpen knives as a hobby but I sharpen those of a professional, high-end chef, who happens to be a friend. He wouldn't care if most of his knives were altered in the tip area. But along with a couple of his chefs, he owns a few knives that he cherishes, and whoever touches them had better make sure they look the same after sharpening. The same is true for many knife enthusiasts.

I'm sure the shot angles in the T2 (101 or 202) videos are carefully chosen, as well as the knife for the demo. I'll gladly send Tormek the reference for a knife and wager a T8 that, when sharpened with a T2 for the first time, will be "sharpie trick compliant" for 80 to 90% of the blade and then completely off at the tip.

The T2 and T1 are targeted for niche markets. Neither is a general purpose machine. In my humble opinion, each of them suits their targeted niches very well.

Agreed, yet again for T2 the target seems to be (I quote Tormek) a "professional kitchen". Which you might agree is quite different from a "knife only sharpening business".
I don't take time to reply to each post where you make the case for the T2 for a professional sharpener just for fun. I genuinely think that not being extremely clear about the consequences of constant-angle sharpening in that use case is paving the way for disappointment and waste of time/money.

If I were to become a "knife only side job sharpener", I'd rather go with a variable-speed belt sander, a coarse-to-ultrafine-grit set of belts and a leather belt, a BGM 100, USB-430 and a knife jig.

Using this setup, curious how would you set up and ensure repeatable 15 dps (or 12, or 17)?

An example can be found in this post. It can be replicated on most backstands, sometimes even without the need for the BGM+USB. An angle cube plus the constant projection method allow for serial sharpening.

I couldn't resist playing along so...

First of all I'm glad you downsized the original "knife sharpening business" to a "knife only side job sharpener".

However the T2 is still the same size and price as in the original post, with the same limitations (constant angle only/pivoting only). So as mentioned in the firestorm (apparently) post, you might want to restrict it further to a "knife only side job sharpener whose customers don't care about bevel looks". I don't think you dishonored a sacred cow : if anything you worshipped - maybe a tad too enthusiastically - an otherwise perfectly fine goat.

As for food processor blades me says if you can hone them freehand on a T2, you can sharpen them freehand on a T-8. Food processor blades don't need sub-100 BESS sharpness anyway given their intended use, so... As for rotary blades I believe the 80-140 mm diameter range offered is quite restricted (my ham slicers are 200 and 250 mm, and they're on the small side of slicers... most slicers I know of have built-in sharpeners anyway).

If I were to become a "knife only side job sharpener", I'd rather go with a variable-speed belt sander, a coarse-to-ultrafine-grit set of belts and a leather belt, a BGM 100, USB-430 and a knife jig. Less expensive than a T2, much faster, much more versatile.

A little info about the knife would help.

The edge looks kinda shiny which is odd for a ceramic blade, but I lack details and might be completely mistaken.

Also, my experience with those hard blades is that they will chip on a very tiny scale instead of being sharpened. So it might be that tiny shocks against the SG might somehow grind the edge, but again, that edge looks very refined to me. I am yet so see that kind of polishing even on a stock ceramic knife.

On the other hand, I have a supposedly "tungsten carbide" knife, that I can sharpen on the SG because it actually consists in microscopic tungsten carbides embedded in a soft matrix. The matrix gets abraded, not the carbides. Maybe some ceramic knives are made in a similar fashion.

I am confused by "concave edges". If you mean cambering edges on plane irons (grinding back the outer edges to eliminate "plane tracks"), the SE77 is the ideal choice, as the amount of camber can be carefully controlled. Before we had the SE-77, we used the SE76 and leaned on the corners. This produced cambered edges which, if not exact, were usually close enough.

The OP really is talking about a concave edge as in ground with a wheel instead of a plate (slightly convex edge) or a belt (more pronounced convexity depending on pressure and belt slack) :

What i don't know is how well or bad planar blades is with a concave bevel? I'm currently using my works sharp belt sander for dito, which gives me a convex edge and that works great.

In theory, convex blades have a tendency to skim/pull out, concave blades will dig in. I don't think you'll notice much of a difference in practice because the convexity will not be that pronounced over the thickness of the blade.

I'm not sure sharpening scissors with the SVD-110 would be easy, especially those with a narrow blade.

The SVX is really fine for scissors, I've never tried to use it instead of the SVD, as I'd worry about damaging the surface with a teflon (or similar) coating. You might get away with clamping a protective plate onto the SVX base jig though, in some cases.

Honestly, to me it sounds like you just need practice.  But I tried to add a couple of tips that may help.

my tip/round part gets more angle. im shopening at 12 and i think is more like 15 or more.

i thought the laser would help when lifter to keep all of the blade edge cutting from the same spot on the stone, to keep the same angle.
Am i misunderstanding this part?

There are many discussions on this subject in the forum including this one.

TLDR : if you try to maintain a constant angle at the tip on most knives, your bevel height will vary. If you want to maintain a constant bevel height your angle will vary.

This is due to the intrinsic geometry of the blade. For instance if the blade curves upward at the tip, it may get thicker because the angle at the end of the blade spine does not correct enough for this. So if you maintain a constant angle, your bevel will get wider.

If you take a close look at videos where a nice bevel is being ground all along the length of the knife, you will notice that the sharpener (Wolfgang included) uses a combination of lifting and pivoting (sometimes away from you, but sometimes towards you).
This is where sharpening knives on a Tormek becomes more than just using a jig in a predetermined fashion. You have to work out what combination of clamping position & clamping angle wrt to the spine, lifting action and pivoting action will work best for the geometry of the particular knife you're sharpening. 

If, like me, you don't sharpen enough knives that you'll be able to adjust on the fly, the "sharpie trick" will help you a lot in finding that combination : blacken the edge, take one stroke just lifting the handle. Look at the edge. If you ground the apex portion but still have sharpie along the top of the edge, add a bit of "pivoting away" action at the end. If you ground the shoulders but not the apex, pivot towards you. Rinse, repeat. When you want to start pivoting will depend on the precise curvature of the blade, so you might want to take a close look at sharpie marks not just in the tip area.

This might only compound the issue you mention in point 2. of your original post. But you will have to build muscle memory and develop habits to get more consistent, there is little helping it.

Hope this helps.

I would point out one possible constraint in your design. The out of round shape of the bore is a patented design held by Tormek called Torlock. I don't believe making a platform for your personal use would be problematic; however, anyone wanting to manufacture them for sale would face breach of patent legal action.

Ken, thanks for pointing this out. I did a bit of preliminary research on patents advertised by Tormek on their website, and could only find something related to this in the patent for the vertical sleeves of the USB. I didn't see anything related to the Torlock mechanism.
That being said, I know of a few other designs where a round shaft is held in, say, one corner of a square hole by a screw, including on a centuries-old loom in a french museum. I'll be damned if nobody thought of making it a triangle (which is essentially what Torlock is) by the time Tormek applied for their patent. The research report for this patent would be interesting in that regard.
Nobody would dare manufacture this on a large scale anyway : plastic filaments will not be very robust in the long run, and a metal version would be very expensive to make.

Guess I don't see the need for a "sliding platform"... the Platform should accommodate just about any size knife without the need for this?   

The idea was to be able to choose the working position (platorm angle) for any grinding/honing wheel diameter, without being constrained by a unique angle/USB combination. I could make one or a few fixed-length variants though, if there are "projection" distances you feel would work well. Those would be cheaper, require one less ruthex insert, and be less "fiddly".

Please share the STL files.

Rich, I'll gladly send you a link to the STL (and/or f3d) files in a PM. Don't you want to wait for the inevitable corrections, though ?

Ken, I understand your point.

But again, I think this is one of the points where the fact still shows, that knife sharpening is what I call an afterthought for Tormek.

Maybe they should think of a "Premium Knife Sharpening Edition", with the knife jigs, new angle setter instead of the AngleMaster, MB-102 and US-430 instead of US-10x.

The standard US-103 support can handle knives with blades up to 200mm (8 inches).

Ken

With very little wiggle room to choose where to clamp the knife, though.

Hello,

Having no metal machining skills nor equipment and few parts to tinker with, I thought I'd give a try at a simple "Platform Jig" that I could 3D-print.

There is nothing fancy or innovative with a simple adjustable plate to rest a blade against, it just feels like it's missing from the Tormek jig lineup.

The objective is to be able to accomodate as wide a range of angles as possible, not limited to short blades but well suited to those as the SVM-00 is kinda fidgety.

I'll use PLA filament for the prototypes and ASA for the real thing, trying to avoid supports except snug ones for the two holes for ruthex inserts (thumbscrews) where geometry matters little.

A quick note on a design choise (which I am not sure is wise): the (grey) sliding platform is more or less self-locking inside the (blue) support. One has to flex it a bit by pressing down in the middle so it slides easily, then release it so it locks back in place, and the (red) back thumbscrew is just here to secure it in place and prevent bending. I might have to play with tolerances and/or add a bit of teflon or the like on the outer surfaces in contact with the support so it slides more smoothly but still locks without significant radial play..

[edit]And a second note : I might not be able to dispense with having to add a metal plate on top on the side of the slide that is close to the wheel, if I have to thin the tip and keep everything rigid.[/edit]

Please feel free to give any feedback that I could incorporate before the first actual prints.

Cheers,

Nick.