Well, here's the US view on the rather iffy practice of running a stone across the jointer knives with the motor on:
1)
While this practice is done, it is normally done AFTER newly sharpened
blades are installed, not to sharpen them, but to joint and dress them so
that both(or all) blades are cutting at exactly the same height. When it is
done, the blades are set at .0005" to .001"...that would be .012mm to .025mm
then using a fine, hard stone on the outfeed table and the cutter head
running, SLOWLY easing the stone over the blades at one end and gently
sliding the stone over the head until you do not feel the blades touching
AND NO MORE! Otherwise you'll actually stone the outfeed table down and that
isn't a good thing.
If you close your eyes and visualize this operation, I'm sure you'll see the
hazards to your fingers are pretty obvious.
Altho it is something that I do, I cannot, in good conscience, suggest to
anyone that hasn't done it, to try. Just a little white lie to myself so
that if something DOES happen to someone trying to learn it, I can tell
myself that I TOLD him not to do it.
2)
I honed the blades on my 54a just as the instructions
suggest. it works fine as long as you are super careful.
those blades are whirling around at a pretty good clip!
"Safe" is a relative term. I was apprehensive about doing
it, but I took my time and made sure the blades weren't
going to hit the stone too deeply. I set the tables so that
the blades barely grazed the sharpening stone. They ended
up very sharp, and of course even with the table.
Personally, I'm still not sure about this practice although I shall have another look at it when re-sharpening time comes. Just the thought of putting a 6" stone near the revolving blades is a little daunting......Maybe build some some kind of holding device for the stone so that fingers are well away from the cutter head.
Rgds
Noel