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Sharpening with a wink, using a lookup table for the sharpening steel

Started by aquataur, August 03, 2023, 07:37:58 PM

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Ha, that´s a brilliant approach from a different side. You vary a different parameter of the right angle triangle.

In seeing your pictures I realize that all of the above contemplations, my idea foremost, are dramatically simplified:

  • the basis of those calculations is a triangle. In real life, it is a segment of a circle with the pivot point being the point of contact knife/honing rod
  • the width of the "wedge", i.e. the width of the blade, is not being accounted for.

The error was considered small, but seeing how close the marking lines on the rod are and how easy it is to miss them, lead me to the following conlusions:

  • the method of using a hone rod is proven working over several decades
  • the operation is probably mostly executed by personnel in ignorance of the underlying principles
  • maintaining a precise angle throughout the action must be uncritical
  • the whole process must be uncritical
  • the process must be simple enough to be executed by personnel not knowing the theory behind it
  • the process must be simple enough to be applied to every hone specimen
  • the calculation must be simplified enough to exclude the need to use specialised equipment (3D printer, PC etc.)

What further supports those observations is, that ideally the honing rod should not remove any material, which is why the mostly revered rods have a "diamond" or "micro-mesh" finish, or none at all. All ceramic rods I have seen fall into this category (besides the fact that a very hard steel very likely needs something harder than itself to rub against...) It (ideally) does therefore not grind a new bevel but re-erects the cutting lip. In consequence, it does not help if the knife is genuinely blunt.

So, back to cbwx34´s method:

I prefer your method over mine, because it excludes the factor "blade height". Furthermore, the reference point is further down the knife´s face where blade with is smaller and the error introduced by ignoring the blade with too.

Seeing how close the 15° and 17° lines are and how questionable it is that somebody can maintain that exact angle, it appears that two lines (15° and 20°) drawn all around the circumference are probably enough. How do you find that folks?

I will later on the day make an extension to above spreadsheet that lets you input your hone´s collar width and calculates the distances for you.


There she goes.

A lookup table to set up a honing rod according to the method outlined by cbwx34. All you need is a fine permanent marker.

There is some caveats:

  • this method is independent of the blade height, the excess back portion of the blade just protrudes past the rim. But on the contrary, a given setup may not work for very slim knives
  • you may have a square rim (i.e. finger protection on the corner of the handle). Choose the smaller one (the bigger one quickly yields distance values only suitable for very big knives)
  • you may have an oval rod. choose a suitable side. Usually the finger protection flanges protrude to the wider side.
  • First tests revealed that it is quite uncomfortable to look at the markings. You better remember, how much your knife sticks out beyond the rim on the top (a further improvement by making a physical stop there comes to mind

This method is no worse than the one outlined by me initially, but only needs a one-time setup. (Maybe an occational touch-up is needed).
Please can somebody verify the calculations.