Feedback about plane blade sharpening analysis

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Jeff,
Thanks for your thougths.
I read the article on your site a while ago and also about hollow grinding in Leonard Lee's book. Both are about chisle sharpening and have created the myth that hollow shapes are less supportive in all cases. The conclusions cannot be easily translated to bevel down planes.
Two methods that require work on the entire bevel to sharpen are a single bevel and hollow _honing_ which is like the Tormek system. For a given included angle the hollow honed shape wins hands down. It has a lower contact height on the frog.
Two methods that require work on less metal when re sharpening are the double bevel (primary/microbevel) and hollow grinding followed by flat honing (as described by Krenov). They have the same geometry at the tip. They can both have the same support angle because you can choose the primary bevel angle or the grinding wheel diameter. But the hollow ground/flat honed method leaves more metal behind the blade and has a lower contact height. So the hollow shape wins this comparison too!
But both comparisons are based on geometry and after that available equipment and the time necessary to make a quality cutting edge must be factored in.
How well does a blade with 12 1/2 degree primary perform in difficult woods?
I wasn't concerned with skitter in my statement but your article is interesting and I'll have to think more about the chatter issue. If the chatter is occuring in the very tip then it doesn't matter how thick the blade is. If the chatter is due to the length of the blade flexing and your plane is holding the blade the best it can then it does matter how thick the blade is. You measured the frequency of the resulting sound which is interesting. What we really need to know is the wavelength in the blade to determine where the chatter occurs. We could ask for some experience...
Has anyone ever remedied chatter by buying a thicker blade? But the two blades were probably different metals with different rigidities.
Thanks again. Your comments will help me word my thoughts more carefully.
Peter
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There are some pretty sophisticated models out there so I wouldn't be so certain that it is insufficient. The real question is whether it is worth modeling or analyzing. Either flat or hollow grind works well enough that I would not bother with trying to determine which is "better". I'm not about to buy a grinding machine to put a hollow grind on any of my tools. That said, my shovel DOES get a hollow grind when I touch it up with the grinder...
-j
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J,
You are right, there are some sophisticated models. But you have to include everything. Like how much slip is there between the cap iron and the blade as the blade flexes. Maybe there is a little slip there. Including all the little things would be tough. Probably easier to build experimental equipment and just test the systems. Probably even easier just to stop worrying and sharpen up a blade and do some woodworking. I was just curious.

haha
Peter
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