Few sharpening angle tips
Keeping the sharpening angle is extremely important.
As mentioned
in the previous post, stones with different thicknesses result in different sharpening angles.
This then may result in an insufficiently refined edge, when a finer stone is thicker than a coarser stone and fails to grind the apex made by the coarser stone.
Since burr detection becomes more difficult as the stone becomes finer, the stone angle adjustment is important for fine edges, say above #600.
Stone adjustment collars are available and help to compensate for this.
But I found that setting the stone angle using an angle cube works better and more consistently.
Benefit of setting the stone angle instead of relying on the pivot angle:
Edge Pro-type sharpeners have angle settings at the stone arm pivot.
You can rely on them if you can set the blade exactly the same for each stone and at each sharpening session.
Below is what I mean.
Let's say that you have a pivot angle setting, with which the sharpening angle is 15 DPS, at a certain blade position on the stage.
When the edge portion of the blade protrudes a bit more than the original position, the sharpening angle becomes shallower.
If you use the stone angle instead of the pivot angle, you don't have to worry about this, as illustrated above.
Potential offset of sharpening angle due to changes in how the blade is set:
Even when you keep the stone angle the same, the actual sharpening angle depends on how the blade is held on the stage.
Let's say you sharpen a blade with the convex primary bevel.
Convex grind makes it easy to shift the angle of the midline of the blade, as the blade may wiggle on the stage.
If that changes, then the sharpening angle will change.
This could happen with a hollow ground blade, though you can secure it better than convex.
The stage magnet, as well as very light pressure to the blade, helps a lot to keep a blade steady.
But I still have issues with convex blades like Opinel
I ended up "clamping" it under the small knife attachment.
For these types of blade, a clamp system might be better.