It's the rounded bevel which confuses people.
All the old books quite rightly warn against "rounding over" i.e increasing the edge angle progressively in search of the burr.
This has wrongly been interpreted by beginners as meaning bevels must be flat.
But in fact "rounding
under" is perfectly OK. The edge stays at about 30º but with the bevel behind rounded. This is what you get if you do easy, fast and energetic freehand honing, but without going over 30º. You start the movement at 30º and dip the handle slightly as you go. It means you are also backing off at the same time and on narrow or thin blades avoids having to grind on a coarser stone.
In fact keeping a bevel flat is quite difficult freehand - hence the attraction of the jig.
I do seem to have to explain this very often (100s of times!
) but if you stop and think about it a bit it's not that difficult to grasp.
I've seen a lot of people who claim that they don't get over 30. Remember when you called me <30 minute refurbishment of an early 1800s plane "confusing" because I described exactly what I did and then showed the plane blasting away at hard figured maple without tearout? I think if I explained to you where you're in a golf swing zone, you'd claim it was confusing.
"golf swing zone" - the principle of someone talking about what they think is happening, what they're doing in their swing, where, how, why, and then showing a video of it and what they think they're feeling isn't what they're actually doing.
In short, the bevel will always be chased steeper, no matter how shallow you want to make it rolling, the geometry of the edge will suffer both in camber and clearance and you're ultimately creating more work for yourself. Hasluck described this better than I've seen. I experimented over time just in the course of daily use to understand this - not sure I would've grasped it without the experience.
Which leads to my biggest annoyance about the discussions never progressing to anywhere without someone getting huffy and claiming it's complicated and nobody does it (when it's not). There's an ability to do this stuff entirely by hand without too much skill - it takes a little experience.
There are two huge myths:
1) that it's physically too difficult for someone able bodied
2) that it's hard to understand and expensive
Quite often, someone will attempt to paint me with strange brushes about sharpening material costs, etc, when I typically use and talk about a sharpening rotation that nobody could possibly not afford if they can afford to buy wood. I *have* some exceptionally expensive stuff, and have had others in the past. It doesn't move the needle, but some details do. Edge fineness makes a difference, edge geometry makes a big difference. As someone continues to work longer, chasing the bevel shallower and separating the honing and grinding is the only natural course.....unless hand tools are a side show to power tools.
And lastly, maybe I'm just wrong about people wanting to work by hand. Maybe they don't want to, maybe they want to imagine it and there's something about really doing it that isn't as interesting as pondering it.