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Tool chests, fathers, grandchildren. 

The arrival of my granddaughter last year spurred a new round of activity for me because it reopened up the field of children's toys. 

A few days before the visit of my granddaughter this Christmas, I fished out of the attic the old rocking horse that my father, at whose knees I learned woodworking and whose Kennedy tool chest is now in my shop, had made for my daughter 35 years ago.  After a few items of repair and refurbishing, I presented the rocking horse to my granddaughter on Christmas Day.  My father, now 97, was thrilled to see the picture of his great-granddaughter on the rocking horse.

Gord

I am a shop rat and a tool junkie, with sub-obsessions in jigs and sharpening, so for years I kept a safe distance from Tormek out of self-preservation.  But my dealer hooked me by telling me I could try "just a little" by getting the BGM-100 for my bench grinder.  You all know how stories like this end: soon I was a goner, and loving it.

My axe jig won't get much use either, because most of my axes are easy to sharpen accurately (enough) on the belt grinder.  But it should allow a greater level of precision for carving axes.  Or at least this is how I rationalized the purchase.  I smuggled it past my wife into the basement, where I keep my stash.

Gord

Ken, I have the same questions you have about the utility of flat grinding on the Tormek, but it looks like there is a demand for this and the diamond wheels are Tormek's response.  So I have thought about your questions in that context.

We know that we need flatness on the circumference of our stones, regardless of how good their radial and axial tolerances, and that is why we use the TT-50 truing tool.  The diamond stones have the ability to keep their factory-made flatness indefinitely, so we don't need to true them, but this makes the initial flatness more critical.  Ridges and bumps are there forever.

The same is true on the flat faces of the wheels.  The reason we true our flat hand stones (and that good diamond plates come with impressive flatness specifications) is that flatness matters.  It probably matters less on a rotating stone because you get the benefit of the inaccuracies cancelling each other out, but ridges and bumps would still be suboptimal, and potentially problematic.

So information on the flatness of the diamond wheels would be informative.

With this said, I would expect the flatness of the Tormek wheels to be good, because it seems like such a controllable variable (machined steel, even coatings). 

As you say, we will have to get some experience with these stones, but as a potential purchaser who is waiting for the diamond wheels to come back into supply, I am interested in observations like Rick's, which redouble my interest in Tormek's target specification and as-built results for flatness.

Gord

Actually, I find the water easier to handle when horizontal and grinding away from the edge because the water doesn't climb over the blade and head astray.  But water control is another skill you will master; keep the level low, just high enough to wet the wheel.  Watch the Bottorff video linked above, he shows how easy it is.

Gord

I want to ask the forum are there folks out there who sharpen using the universal bar in a horizontal position with the wheel turning against me?

As Ken says, with a little practice you will be proficient at grinding into the edge.  That is the technique I prefer.  However, there are some very experienced knife sharpeners who prefer using the bar in the horizontal position, with wheel turning away from the edge.  Here is a link to Steve Bottorff's YouTube video, in which he demonstrates and explains his preference for this technique:

https://www.youtube.com/watch?v=BKjMilG9LWY

Gord

That is interesting information Ken, thanks for getting it. 

It might be that the superior tolerances come from the greater precision that can be achieved in machining steel vs. stone.  With that said, I would not be bothered much by minor runout on the flat face because at the low speed of the Tormeks it should only result in some gentle movement of the blade/tool. 

I think that flatness is another specification that would be relevant in some applications for these wheels.  (Diamond plates will often advertise flatness in the .025mm-.05mm range.)

Gord

Ken, I agree with you that we should be respectful of Tormek when discussing the price of their equipment, but I don't think that it is necessary or prudent to restrict that discussion from the forum. 

I would say it is not necessary because Tormek is quite familiar and very good at defending the cost of their equipment, and they sometimes do it explicitly (See the Stumpy Nubs interview with Stig, the topic of which is why Tormek costs so much.  Stig knew that this is a question that Tormek has to be able to answer, and he did it well).  The value proposition of Tormek equipment is a very common topic of discussion on other forums.

I would say a ban on price discussions is not prudent (not in Tormek's interest) because it could damage the credibility of this forum and make it appear that Tormek is afraid to see discussion of its price and value ratio.  As noted, I don't think that Tormek shies from that discussion.

Though I have not been on this forum for long, I have seen that most members (and myself) are capable of defending the value of Tormek products.  But not everyone has an unlimited budget, and to some Tormek users the price of alternatives is not irrelevant.  No one is saying (or at least, I have not seen it said here) that the prices of Tormek products (the stand, the mat, the wheels) are inappropriate for their quality—that is, members are not saying that Tormek is gouging.  It is just that some people are price sensitive or might not see the need for the very high quality of a particular Tormek item of equipment. 

I would hazard that most members do not have the Tormek stand.  It is not that they don't recognize the quality of the stand or the reasons why it is so expensive, it is just that they find less expensive alternatives to be satisfactory.  And how many of us use a dish mat or a boot tray or (me) a pizza pan instead of the Tormek mat?

Price is just one part of the two part "price/performance" equation, and we surely cannot exclude discussion of performance when some non-Tormek alternative (a homemade jig, a jig made for another machine) provides performance that is superior for some purpose to that of the corresponding Tormek equipment.

When I reviewed the Hewn & Hone jig for the Tormek, of course I noted that it was very expensive.  It is easily twice as expensive as the Tormek knife jigs.  But it has a function, and if you would benefit from that functionality it is good value even at that high price.

About CBN wheels, if you compare feature-for-feature, the CBN wheels with steel or aluminium frames and three sharpening surfaces (like the Tormek diamond wheels) are almost exactly the same price as the Tormek diamond wheels.  But there are CBN wheels that are less expensive because they have different frame materials and only one sharpening face.  This is not to say that the Tormek diamond wheels are not good value, but some users might have a price sensitivity and/or a more limited need for functionality. 

I am confident that Tormek would not benefit from the appearance that they are shy of this discussion.  It is my impression that when Tormek is confronted with a debate about their prices, their attitude is (quite properly) "bring it on". 

So, acknowledging your important point about being mindful of the hosts of the forum, I think the goal should be to keep the discussion respectful, but not to restrict it by topic.

Gord

CBN wheel aficionados will insist that their wheels can touch up carbide tools, and D-Way says their CBN wheels sharpen carbide, but I think that there is general agreement that diamond abrasives are the way to go for carbide. 

If I were making only one of my Tormek wheels a diamond one for this purpose, I would get the "extra fine" Tormek diamond wheel, to get a clean edge.

But with that said, if carbide sharpening capability were the reason I was getting a diamond wheel, I would want to hear some reports of people sharpening carbide tools at the low speeds of the Tormek before I made the purchase.  It might be rather slow and the edge might not be great.

Presumably Tormek has tested these parameters, I wonder what their results were.   

Gord

Ken, I am wondering if you experience different results with your diamond wheels compared to your CBN wheels.

About "designed in" wet use and 12mm bores, I got my 250mm CBNs to use dry, but I now also use them wet with good results.  I don't think of the 12mm bore in the middle of my wheels as any less designed into the wheels than those in a Tormek wheel.  So I don't see the significance of those points.  And as with you (or at least as I take it from your comment in the thread started by Pastor Zatx) I don't mind (and sometimes want) the hollow grind, so I am happy to work on the circumference of the wheel.  And the flat grinding option on the side of the diamond wheels would not be my first choice for flat sharpening tasks when I have them.

So, I keep wondering about results: is there a difference between CBN and diamond in the Tormek application? Maybe no one has done a comparison and the data aren't there.  But it could matter to some, because the 250mm CBNs are about $180 and the diamonds are about $330.

Gord

Funny thing, a few hours after posting about the oils for honing leather wheel I was stropping some carving tools on my flat strops, and smiled to note that I infuse the honing compound into these strops with a suet/abrasive mixture I learned from and English carver.  Suet! I won't be dripping suet on my Tormek stropping wheel, but the thought I had as I stropped away was that the objective is to get the honing compound into the leather, and probably many lubricants will do the trick.

Gord

If I was beginning with the Tormek, after the SG which comes with the Tormek, my next wheel would be the 360 grit diamond wheel.  I would skip CBN.
Ken

It would be good to have a comparison of CBN and diamond wheels on the Tormek.  My $180 CBN wheels (10") seem to work very nicely wet and dry on my T8.  I have been waiting for diamond wheels to come back into supply, but now I am not so sure that I will be keen to plunk down ~$330 each for the Tormek diamond wheels. (I don't need the flat sides.)  All of which is to say, with cost as a factor, the performance comparison would be useful.

Gord

I can see two different concepts here.  CB is noting that there is a smaller difference between a 200m and a 180mm wheel than between a 250mm and a 200mm wheel, which Ken has found irrelevant, whereas (in this post) Ken is not talking about the difference but the point at which the diameter of the wheel results in a hollow grind that is "too hollow"; that is, the apex might not be sufficiently supported by the metal behind it.    The ultimate question is the radius of concavity at which a hollow grind results in insufficient support behind the apex.

And yet, as with CB, I don't understand Ken's concern with using a 180mm wheel on a T8, or moving it over to a T4, if a somewhat worn 200mm wheel (at 180mm) is fine on a T4. The point could be important to those choosing between a T8 and a T4, because the wheels on the latter might not be able to provide as much service before the degree of hollow grind becomes too great.  Maybe Ken can elaborate.

Gord

I find that the terminology can be confusing. 

Sewing machine oil and 3-in-1 oil and the like are all mineral oils (petroleum-based oils). 

The mineral oil you get in the drug store has some bad stuff refined out of it, and so gets called "pharmaceutical" grade or more generically "white" mineral oil.  This is what Tormek provides with their new machines for the conditioning of the honing wheel (see the manual and their MSDS for the oil), but that could be more out of concern that someone might use a kitchen knife after honing without washing it, than any particular qualities of the oil for conditioning the wheel.  Interestingly, Tormek has not chosen a vegetable oil, such as might normally be used for conditioning leather, perhaps because mineral oils will disperse better in the honing compound.

Sewing machine oils can have different viscosities but tend to be about the equivalent of about SAE 10 and 3-in-1 about SAE 20. 

I don't know if either of these viscosities would be better (I can think of reasons why each might be better) but drug store mineral oil is so easy to get, and it is what Tormek supplies, so that is what I would use.

Gord

This is a common caveat with CBN and diamond wheels, the concern being that some (merely) high carbon steels are not inherently hard enough or haven't been hardened enough, with the result that they could clog ("gum up") the abrasive array on the surface of the wheels. 

However, I don't find the term "high carbon steel" very useful in this context.  It is true that CBN and diamond wheels excel on high speed steels and the newer super hard steel alloys, which pose no risk of clogging the wheels. But some high carbon tool steels can be quite hard and users report that they do not harm their CBN wheels.  Also, some who have experienced clogging have found that the wheels can be cleaned up by grinding some high speed steel on them.

But as Ken is wont to remind us, the standard Tormek grindstone is excellent at high carbon steel, so you don't need to put your exotic wheels at risk.

Gord 

I cannot see how this could be done, the honing wheels have a function in the drivetrains of the machines, so they are one-grinding-wheel machines.

Gord