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Though I agree that sharpening with the Tormek (T3/4/7/8 SG2000, ...) requires training, patience, and skillbuilding, I think it's fair to say that you shouldn't need a non-included truing tool to be able to sharpen properly. And *if* the wheel is indeed out-of-square with the USB, then the blame falls squarely with Tormek.

That being said, that's a big "IF" : I don't think Tormek has begun shipping SG grindstones that are not square within acceptable tolerances. So the USB setup must be to blame, and though you might be able to true your SG-200, that won't work with, say, a DF-200.

So the way I see it : if the USB is indeed not reasonably parallel to the shaft, then I'd suggest dealing with Tormek support. But before that, I'd make sure to set it up using the recommended procedure where you press down on the threaded leg before tightening the corresponding knob, then the other one.

That doesn't mean that you won't eventually (or rather, soon) need a truing tool. But you shouldn't mess up your stone needlessly. And yes, the T-4/T-8 choice might actually be more real-estate-driven, rather than financially driven, all things considered.

[EDIT] The wheel being untrue when you checked it might be the result of your first sharpening sessions, where you might have applied pressure unevenly. A good way to check this would be to use a precisely machined square : if you see light shining through between the square and the top of the wheel when you lay one side of the square flat against the side of the wheel, then that's most probably the case. You could also check the trueness of your USB by tightening it as mentioned and using the side of the wheel as a reference for your square. [/EDIT]

Ken, the idea of the formula was to substantiate a reply to an objection regarding the choice of words of the OP.

I am no Richard Feynman, so I will not be able to be as clear as a professional teacher. Still, to make a long story short :

The concept of impedance is a generalization of the concept of resistance, i.e. the proportional relationship between current and tension. With a resistance, everything is simple : tension U is related to current I by the U=R.I relationship.

For a capacitor, U is related to the integral of the current over a period of time. But using mathematics in the complex world, integrating is "simply" dividing by j.w (assuming a sinusoidal current, and where j²=-1 and w or "omega"  is the pulsation of the current). So one can write U=Z.I with Z=1/jCw.

Conversely, for a solenoid, U=Z.I with Z=jLw.

Therefore, in electronics, impedance is a generic term covering at once R,L and C. And asking for the impedance of a capacitor is another way of asking for its capacitance. Pretty much in the same way that asking someone for their address will give you the name of their hometown, and a bit more.

As for E=m.c², if I may, there might be a slight twist in your VHS or your recollection of it. To apply E=mc² to your baseball, you would have to thoroughly disintegrate said baseball, and the energy released (in the form of massless photons) would be m.c², m being the rest mass of said baseball. If you could accelerate the ball to lightspeed, its mass would change and things get pretty messy from here. But e=mc² is always true, even for a baseball at rest. And you cannot accelerate it to c², which is not a speed.

Hope this helps,

Nick.

Impedance covering capacitance+inductance+resistance (Z=R+jLw+1/jCw), OP was correct...

Aside from specific, occasional sessions where I combine diamonds and SG,I usually leave the water trough to rest for a day, on the lowest position. This allows for the wheel to release the water it absorbed, and for the slurry to sediment on the bottom.

Afterwards I empty the (mostly clear) water in the sink, and the wet (yet compact) slurry goes to the trash.

It seems ChatGPT is now an expert. The definition of which being : Someone who knows how to err with authority.

I use an old tall and skinny glass jam jar with a piece of foam wedged into the bottom. I just insert the knife, fill with whatever cleaning agent I want (typically dishwashing detergent) and immerse the jar into the ultrasonic cleaner filled with water.

This setup allows me to use different cleaning solutions at the same time for different knives, and makes cleaning up a lot easier.

Nice, thanks for the tip. Could you share a pic of your setup ? I just ordered a 15 liter cleaner, so I probably will have to use a similar setup to avoid using 15l of water+solution for each knife batch. I will also use it to clean pasta dies, with warm water and dish soap.

In that cas it will probably have constant measurements hardcoded into the software. So, hey, why not. But I'd rather use tested tools such as those mentioned above.

thanks.  so in other words, remove the grinding wheel altogether while honing and use the pvc pipe as a spacer between the motor and the locking nut?

 Yes, especially if you want to do angle-controlled honing with a MB-102 (or FVB).

so nervous to sand paper the rubber wheel.  what are your thoughts about removing the leather part and then replacing it.  will it be loose afterwards.  is it easy to take on and off?

Well there's not much to be nervous about if you sand the rubber wheel gently. I've done it with coarse sandpaper for the best part of an hour and it doesn't show much.

I wouldn't do the whole unglue/glue back thing with the leather strip. You will probably damage it somehow in the process, and if you can't glue it back properly afterwards, with the proper overlap but no kinks nor extra lengths nor anything... then you'll probably be in more trouble than you are now.

You could still try to sand the area where the glue joint sits in between the two ends of the leather strip - as described in your manual - but I doubt the glue is causing a bump on a brand new leather wheel. Who knows though...

No worries, here goes :

- Yes, sandpaper. Not the stone grader.

- The rubber wheel (or drive wheel) is what you see when you remove the entire honing wheel by unscrewing the black plastic nut. This is where the motor shaft transmits power to the shat that links the honing wheel and the grinding wheel. If there is a slight bump on the rubber wheel, your honing wheel will wobble a bit each turn. Sanding it will softly will remove the bump, and increase friction (so, traction).

- I attach a picture of the Tilt Feet used in lieu of the (removed) grinding wheel. You can use a 50mm-long PVC pipe if you lost the white one that came with your machine and don't own the tilt feet. You just need that if you don't want to angle your honing direction some 20-30 degrees.

Is that clearer now ?

And as mentioned often, measuring to the surface of the wheel eliminates the need for these intermediate measurements and associated errors.

Plus it is not really harder than measuring straight to the right spot on the casing.

Hello.

The bumpiness is a very common (albeit harmless) issue with new honing wheels. You can solve it by removing the honing wheel and gently sanding away the top surface of the rubber wheel. If you search for "rubber sanding" in the search function of the forum you'll find plenty of references.

[EDIT] You may also want to sand the leather wheel as well if that's where the bump comes from. You can reference your instruction manual for this[/EDIT]

As for the knife touching the grinding wheel you have two options :
- If you hone freehand, you can angle the knife on the honing wheel so your direction of travel does not interfere with the grinding wheel.
- If you hone with a jig (MB-102 or FVB) or simply want to hone freehand but parallel to the shaft, you can remove the grinding wheel, and put a piece of 20mm PVC pipe (of the plastic pipe that came with your Tormek) on the shaft then put the Ez-Lock nut back on. The recently released Tilt Feet can also be used to that end.

I've made a quick benchmark of french vendors, both for material and liquids.

I do not have the precise reason yet, but it seems that liquids that work well with stainless steels are restricted, and sold only to some professionals.

As for using those cleaners with knives, I think one would have to create some kind of holder to keep the blade immersed, but clear of the walls and floor of the tank. I'm thinking electrical wires to support the handle and spine.

I didn't, and I am not sure what their "proprietary software" would bring over those in @cbwx34's signature, or TormekCalc.

Why anyone would pay 20 EUR to use software that just replicates basic geometrical considerations (see this geogebra sketch ) is beyond me.

From personal experience, go for the largest capacity ultrasonic cleaner you can reasonably afford. I guarantee you'll be throwing a lot of other items in it once you've experienced what it can do.

* reads this while thinking this 15L USC might just be what he needs *

If that's not asking too much, do you think you could :
- Try this method after just SG grinding + leather wheel/PA 70 honing, and see how BESS scores are affected ?

Um, that's exactly what I did.
I was aiming for the best possible grind and hone i could do, and so for the first time ever I hones on the front jig holder and took extra care to adjust the angle in small increments to break off the burr as carefully as possible. I think that also will become standard practice in future for me.
I only use the standard leather wheel with the Tormek paste, but I'm keen to get another fresh wheel and try the Veritas Chromium oxide paste. This is what Dr Verdim recommends. 

Wow, the scores you mention before using the USC are impressive. Like 80 without stropping. Thanks for the answers, and you got me wondering what a suitable USC would be and what it costs... I've been looking around and saw some 6 liters dual transducer 40kHZ cleaners around 250 EUR.