hollow and flat grinding

[Ken S]

I will be curious to see the next edition of the handbook. The three new diamond grinding wheels with flat side abrasive add new dimensions to Tormek grinding, as does the new MB-100 multi base. I have long felt that the debate about hollow ground edges with the 250 or 200mm diameter Tormek grinding wheels is overblown. The handbook explains the very slight degree of hollow grind from the large Tormek wheels. I have observed the same thing. The hollow grind tradition goes back to the days when most of us were using six inch (150mm) dry grinders.

How many of us will switch to flat grinding using the sides of diamond wheels? We may even see the old mini debate about whether to grind perpendicular or parallel the cutting edge resurface. Both sides have supporters with jigs for bench stones.

Diamond wheels cut differently than aluminum oxide. I have found that the DWC-200 with a 360 grit cuts more aggressively than the SG-200 with a freshly graded 220 grit. It also requires a lighter grinding pressure for longevity.  Grit is only one factor.

There is much to learn about the new techniques and products. I look forward to reading about it in the handbook. I hope there will be new in depth videos, also.

Ken

[cbwx34]

Call me crazy, but now they need to add a piece of leather to the side of the honing wheel.. to eliminate the issue of rounding the back of chisels... etc.  (Notice how often they emphasize not doing this on the leather wheel).  (It would definitely be "task specific").

I agree that the "hollow grind" debate is a bit overblown... (even if it was done on a bit smaller wheel than the Tormek)... I'd bet in a "blind" test, most couldn't tell the difference, if they didn't know how the knife was sharpened.

You have some good observations about grit, cutting ability, and pressure using the diamond wheels.

[Ken S]

The flat honing wheel was just one of my off the cuff thoughts, "they" had nothing to do with it.

Like you, hollow ground or not is not a big deal with me.

Thanks for your compliment about my grit, cutting ability and pressure observations. I believe there is more to these topics than was covered in the handbook a generation ago.

Ken

[cbwx34]

The flat honing wheel was just one of my off the cuff thoughts, "they" had nothing to do with it.

Like you, hollow ground or not is not a big deal with me.

Thanks for your compliment about my grit, cutting ability and pressure observations. I believe there is more to these topics than was covered in the handbook a generation ago.

Ken

If you mentioned a flat honing wheel somewhere... I missed it. 

There's a sharpener on YouTube that talks about sharpening pressure (on waterstones).  Since it's not Tormek related, I won't post a link, but type "sharpening pressure" in a YouTube search, and his video is on top. 

BTW, another sharpener did a study on sharpening parallel to the edge (you mentioned in an earlier post)... they found that sharpening parallel did some weird damage to the edge... mainly some odd chipping that would show up.  Never could figure out why ('cause for polishing it worked great), but to finish the edge it was done with perpendicular strokes.  (Just a little tidbit of info in the sharpening realm). 

[Ken S]

CB,

I did the youtube/sharpening pressure search and watched the video. I thought it was well done and interesting. I am starting to think there should be two handbooks, a quick start guide and a more advanced version. I would guess that almost everyone would start with the quick start guide and that most would stay there. I certainly have no problem with that. They are getting consistently sharp enough edges. And then there are those who want sharper and/or longer lasting edges.

At that level, the trick is to sift out the marketing hype. Years ago on the forum, Jeff Farris and I had an occasionally running joke. "How many angels can dance on the head of a pin?" It was shorthand for anything which went far beyond any usefulness. It was a joke for us, although, during past centuries with the Inquisition, the wrong answer might get you burned at the stake. 

Personally, I have no problem with articles and youtubes which are not Tormek specific within reason.

Ken

[SharpenADullWitt]

For me, the side of the wheel will give the opportunity to use it for flattening backs of chisels and plane blades.  I expect it might also be great for the backs of serrated knives, where I use the wheel as the "flat line" to have an even surface.

I have a T2 coming, so I will be interested in if there is anything different with its honing wheel and doing serrated knives. (no good english video's)

[Ken S]

SADW,

I just double checked. If you add the spacer washer (slipped on your T2 behind the grinding wheel) onto the shaft of your SuperGrind size Tormek, the DWF-200 will fit perfectly on your SuperGrind or T7/8. It will work as well as any other Tormek wheel worn to 200mm. This will let you use the DWF-200 with any of the Tormek jigs and also Herman's HK-50 platform.

This gives you the choice of using the T2 as designed for restaurant work or having the full flexibility of the Tormek using your existing Tormeks and DWF-200, a very versatile combination.

I was surprised when working with the CBN wheels, with a width of 1 1/2" (or approximately 38mm) that I felt no constraint by not having the full 50mm width of the SG-250. The DWF has a width of 40mm.

You have a very unusual advantage working work restaurant people. I look forward to reading your observations. Do keep us posted.

Ken