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FWIW, here's my video on the dual-wheel setup:
https://www.youtube.com/watch?v=nowd-O3HT50

I convexed a couple pocket knives out of curiosity.  It worked pretty well, but it's quite a slow process if you want to get nice looking results.  It's not something I plan on doing again.  I also don't think it's a good solution for knives that already have convex edges, because there's no way to match the height of the existing convex section.  To be truly useful for that purpose, you'd need to be able to adjust the distance between the stops.

I think that the added weight of a second grinding wheel probably stresses the motor more than running it with a single wheel, but it has more than enough torque, so maybe not?  It's also putting more stress on the shaft, but again ... I don't think it's doing any harm. 

I have no idea if running two wheels voids the warranty.  I suspect it probably does, but I've been running mine that way for well over a year with no problems (dual CBN wheels).  If you get an official response from Tormek I'd be curious to hear the answer.

I can imagine that the SG, graded fine, could be a good place to start for grinding out larger chips.  But from there I think it would best to move on to higher grits.  I wonder if the Japanese Wheel would improve the SG result?  After that 4000 grit finish, six, three, and one micron stropping could be the ticket.  Or sharpening on 8000+ bench stones and then stropping. 

Anyway, I'll have a go at it when the factory edge gets chippy enough (and it seems to chip quickly with my wife/chef behind the wheel).

Nice, Kwakster!  I've never gotten along with paper wheels, personally, but your results speak for themselves.

I believe this is an interesting read at
ScienceOfSharp.

It states that aluminum oxide abrasives are sufficient, however a much finer grit than the SG-250 is suggested.

Very interesting. It seems Kyocera has improved their sharpening process since that was posted in 2018.  My examples easily push cut paper.

Do you happen to remember what your edge angle was, CB?  Outdoors55 from Youtube recently posted a video about sharpening ceramics on resin-bonded diamond stones.  He had many unsuccessful attempts using various stones, but eventually concluded that the key was to use a more obtuse edge angle. 

https://www.youtube.com/watch?v=FFEgg7OWsUk&t=508s

I found that curious, since my two Kyocera ceramic knives came with factory angles of 13 and 14 dps.  I wonder how they sharpen them at the factory....  They measured at 100 and 110 BESS, which is waaay sharper than any factory edge I've gotten on a steel knife.

I can usually tell from slicing paper (I use the Uline catalogue) what the BESS score is going to be, give or take 10-15 grams.  Whittling hair is another good analogue for the BESS tester.  If you can't whittle a hair (or cause it to split on contact), you've probably got a BESS reading over 135.  If you can whittle a hair, but you have to mess around with it for a while to get it, you're likely in the 110-135 range.  If you can do it on the first attempt, and pretty much anywhere on the edge, you're below 100.

As far as the BESS tester only reading a tiny fraction of the edge goes, I don't find that to be a problem.  My edges are generally consistent from tip to heel after sharpening.  If I get a reading of 100g in one spot, I'm going to get the same reading +/- 5g anywhere else on the blade.

Two wheels on a Tormek?
They interfere with each other when sharpening.
That's also the reason I have to remove the wheel if I want to use the honingwheel.

Surprisingly, it isn't often a problem.  Why?  Because most knives that are long enough to be a concern have a curved belly towards the tip.  When you raise the handle to hit the belly, it eliminates the problem of impacting the other wheel.  Thus, even a 10" chef's knife isn't an issue.

You can even work around a long, straight knife by holding the sides of the handle instead of wrapping your fingers around it.

The leather honing wheel is only a problem because Tormek nonsensically opted to give it a smaller diameter than the grinding wheel.

I'd set up one Tormek with dual wheels: 200 and 600 grit CBN or the diamond equivalent.  Then use your 1x42 with a leather belt to deburr/strop, or in the alternative, a slow-speed grinder with leather wheel.

To me, 600 is the perfect finishing grit for kitchen knives.  After stropping, it's refined enough to cut smoothly but has enough tooth to avoid glassiness. 

The exception would be high end Japanese knives, and particularly those meant for slicing fish.  I'm told that you want at least a 4000 grit finish on those.

As far as CBN versus diamond, it doesn't matter for slow speed grinding.  They will perform the same.  What may be important to you is wheel construction.  Tormek diamond wheels have wide coverage on the sides, which is useful for some sharpening tasks.  Some CBN wheels are made out of aluminum, which is better for wet grinding without the expense of anti-corrosion additives. 

So ... how sharp is sharp enough?

The answer is obviously ... depends.   

My opinion has changed over time.  Used to be, I wasn't happy unless I could get a knife to 75 BESS or lower.  Nowadays I'm satisfied if it's under 100 after sharpening.  I almost always do a 15 dps edge, and I can maintain edges in the 100-120 range with stropping for quite a long time before I need to resharpen.  If I can't get it back to 120ish, then it's time for a fresh edge.

But I think most of us have standards that are wildly different from the general public.                                                                                                                                                                                                                                                                                                 

I agree, edge retention is very important.

It's not often you see BESS results from 24 hours after initial sharpening. Rarely will your sub-100 BESS knife remain that way the next day, even without use.

Absolutely true!  Even the slightest amount of oxidation, even on very stainless steels, will raise BESS scores over 100.  That said, however, it's very easy to bring the scores back down with light stropping, or even cutting stuff that isn't super abrasive.  I think that's why Wootz found improvement in his BESS scores when testing cutting boards, after the first couple of cuts.

I wonder if the WTW CBN wheels have changed since this old thread was posted?  I've been using the 600 grit CBN wheel for a while.  I don't have thousands of sharpenings on it, but certainly hundreds. 

For starters, the one I purchased in 2023 fits perfectly on the machine, provided you mount it properly.  It's designed to mount with logo/grit rating facing the machine.  It fits the water trough on my T-8 fine, but you can only crank the trough up 4 clicks.  Being slightly wider in circumference, it will rub if you crank the trough up 5 clicks.

It is problematic if you try to mount it with the logo facing out.

I did a comparison between the 600 CBN and the SG-250 graded fine, using the Tormek stone grader.  Knife was a Victorinox 6" utility with a 15 dps bevel.  I ran the edge across a 400 grit diamond plate to take the edge off. 

Results:
CBN 600 -- raised a firm, complete burr after two passes per side, alternating sides after each pass.  Stropped on Ken Onion Elite with leather belts.  Two passes at 16.5 dps with 1 micron diamond.  Four passes at 15 dps with PA-60.  95 BESS.

SG-250 fine: I gave up after a dozen passes per side without raising a burr.

SG-250 graded with 400 grit diamond plate: raised a firm, complete burr after two passes per side.  Same stropping routine as above.  110 BESS.  Did additional hand stropping on leather with .5 micron diamond, two passes per side: 100 BESS.