Originally Posted by
Warren Mickley
David says he sees no disadvantages. As I pointed out on this forum in July, the major disadvantage is the extra time needed to execute the "ruler trick", thirty seconds in his December 2015 video. As I recall the time to sharpen a plane iron was in excess of two minutes and that does not include any time for grinding, which he obviously does, or for stropping which he apparently omits.
A minor disadvantage is the angle of the edge; David shows a 35 degree bevel angle plus a 2/3 degree back bevel. When I experimented with bevel angles forty years ago, I noticed a poorer result for bevel angles of 33 an 35 degrees (as opposed to 30). 35 2/3 is uncharted waters for me.