CBN Wheel for Tormek

[bobl]

Just a point.
A     C.B.N. wheel should be run dry.
That is one of the benefits of C.B.N.
Dont use it as a whetting wheel. It is designed to be run dry.
Lets go from here.
What are your experiences on it dry.
Bo
The Knife Grinder

[Ken S]

I agree that CBN wheels work very well dry. Initial tests indicate that they may also work well wet. My testing is still in progress. Until I feel that my testing is complete, I don't want to limit my options.

Ken

[Ken S]

Ken, I like the David Charlesworth approach but it is only for blade with already flattened back. He describes a ruler trick how to remove a burr after sharpening the edge while blade back should be reasonably flat before the edge sharpening.

Based on my experience the plane blades are often concave and you have to flatten circa 25 mm from the edge. Recently I was sharpening a 50 mm (2 ") plane iron with 59-60 HRC and I needed 15 minutes to flatten its back on the side of the SG stone graded coarse. It was a very difficult task. I had to de-clog the stone side several times during the flattening. I cannot imagine to do this flattening by hand using the waterstones.

My client was a violin maker, so his claims were quite high. He told me that after the blade flattening and sharpening the chips thickness dropped by one third. 

Jan

Jan,

Interesting point. My 1000 grit waterstone is now almost half size due to flattening too many backs. (So are my fingers. ) I don't recommend oilstones, either. I believe the key to success in flattening is to start with a coarse enough abrasive.

I spend several hours flattening a very hard oilstone using carborundum powder on a glass plate (with water). A steel plane blade might flatten more quickly. This method would be much more cost effective than a large coarse diamond stone or flat plate for occasional work.

How did you deglaze the side of your grinding wheel? The handbook is strangely silent about this, and it is a real issue.

Checking with a straight edge, I think it would be possible to use the round face of the grinding wheel to remove most of the high spots. The molding cutter jig works this way. If you were able to remove most of the metal this way, finishing on the side of the wheel or by other methods would not be so laborious.

Your effort has resulted in a substantial improvement in plane performance for the violinmaker. Bravo!

Ken

The cowardly, expensive option would be to purchase a new, hugh quality blade. These are thicker and surface ground at the factory. My less logical, emotional self would prefer to spend the time to correct the original blade.

[Jan]

Thanks for your response, Ken! 

I do not have a suitable set of waterstones with different grits and I am not sure if I would have enough usage for it. For tools flattening I am using either a bench-mounted belt sander with 240 grit or the side of the SG stone.

The belt grinder works more quickly than the SG stone, but when the belt is worn out and hot it is often bulged in the middle of its width. The bulge causes that the blade back is not exactly flat, it is a tendency to concave it. That is why I prefer the grinding direction away from the edge, because the belt is pressed down before it reaches the sensitive area near the edge.

For unclogging the SG stone from embedded steel particles I simply use the coarse side of the Tormek stone grader. Quite high pressure is necessary for some 45 seconds. 

What concerns the mentioned violinmaker, he uses the plane to stitch the halves of the top and back plates. The top sound-table is made of soft tone wood – spruce while the rear part is from hardwood – maple.  The plane iron was ground with a 28°edge angle.

The violinmaker is satisfied but may be applying the David Charlesworth approach would make him even more happy. 

Jan

[Ken S]

Jan,

I would not purchase a set of waterstones to flatten an occasional plane blade or chisel. I think the cost effective way is to get a piece of thick plate glass and some wet or dry sandpaper in varying grits. The sandpaper gets consumed, but the glass lives to sharpen another day.

My daughter plays the cello. I have enjoyed meeting several violinmakers over the years. I am pleased your efforts were successful.

Ken

[Jan]

Yes, Ken, I agree with you. During my pre-Tormek period I was using a flat and polished marmor (marble) plate and my own honing guide. Both worked fine. It had never occurred to me how excellent Swedish equipment I will have one day. 

Jan

[Ken S]

Jan,

I believe the real key ingredients in sharpening (as in life) are experience and imagination. While the Tormek is quite versatile, there are times when a flat plate is a useful supplement. The wise sharpener knows which tool to use for the job at hand.

The wise sharpener also knows the job requirements. A violinmaker making very thin, precise shavings, would want a more highly tuned plane than most users. He also might prefer to have the original blade made extremely sharp instead of purchasing a new, thicker after market blade. His preferred way to prevent blade chatter would be skill and sharpness.

Working with this man would be satisfying for a dedicated sharpener.

He found the right sharpener.

Ken

[Ken S]

Looking at the photos in Wootz' original post, I am disturbed by the very small amount of thread holding area with the EZYlock nut. The saddle in the grinding face is a manufacturing defect, presumably from a "bad batch", which should be correctable at the factory. The lack of thread gripping is a design problem. Presumably this could be easily corrected by insetting the middle of the wheel, something I have seen only on Tormek wheels. What bothers me is that this problem was not discovered and corrected during design. It makes me think that the designers did not actually test it on a Tormek before placing it on the market.

The dealer seems supportive and honest. The basic product seems sound and useful. I hope the dealer will correct the saddle defect and redesign the wheels to thread correctly on a Tormek.

Incidentally, I mounted my King 600 grit wheel yesterday. The bore fit is very snug. Unlike with Tormek wheels, it is necessary to hold the leather honing wheel with one hand to prevent the shaft from moving. This is really not a problen. The slightly oversize diameter does fit in the water trough. The bore area is not inset, as in Tormek wheels. This makes any side of the wheel dressing more difficult, but would not effect using the face. The nut threads fully, due to the wheel being slightly thinner than the Tormek wheels.

Ken

[Ken Rizza]

I know this is an old post but thought  I would mention that the saddle issue on the Tormek CBN wheels is a thing of the past.  So is the ringing problem that  some people experienced.  Our two new style wheels - the Spartan which has a nylon center and our Tornado which is has 1 inch of grit down the sides also are dead flat.  We no longer make or carry the style wheel that had saddle issues. Thanks.  Ken Rizza - Wood Turners Wonders.

[Ken S]

Ken,

Thanks for posting. Old posts often linger long after problems have been resolved. I'm glad the saddle issue was resolved.

(the other) Ken

[wootz]

I know this is an old post but thought  I would mention that the saddle issue on the Tormek CBN wheels is a thing of the past.  So is the ringing problem that  some people experienced.  Our two new style wheels - the Spartan which has a nylon center and our Tornado which is has 1 inch of grit down the sides also are dead flat.  We no longer make or carry the style wheel that had saddle issues. Thanks.  Ken Rizza - Wood Turners Wonders.

True, just to confirm that, I use both the newer Spartan and Tornado and can't be happier. Excellent support from Ken Rizza at all times.

[Sharpco]

I know this is an old post but thought  I would mention that the saddle issue on the Tormek CBN wheels is a thing of the past.  So is the ringing problem that  some people experienced.  Our two new style wheels - the Spartan which has a nylon center and our Tornado which is has 1 inch of grit down the sides also are dead flat.  We no longer make or carry the style wheel that had saddle issues. Thanks.  Ken Rizza - Wood Turners Wonders.

I ordered Spartan CBN wheel #200 in Jan, but it had the same problem. But I couldn't replace or refund it because I'm in South Korea. So I'm waiting for Tormek diamond wheel.

[Grizz]

oouch !