The 5/8" rule isn’t a rule - it’s just a nominal height over the jaws at which the degree graduations are approximately accurate. Where users have wondered why they measure different angles than those shown on the bar, it’s probably related to the height of the blade they have clamped.
I always use an angle cube, but that in itself isn’t enough if the center line of the blade is tilted; hence, Josh’s (and others’) subtract and split the difference method.
Still curious if the G3 clamping issues are resolved.
If you place an AngleCube on one of the diamond plate stones, you’ll find that the angle will change as you slide the stone up and move the grip point above the edge. There is some clearance designed into the blocks to allow for contaminants and such, so that the stones continue to move freely on the rods. This also allows the stones to rotate slightly on the rods. When hand pressure is applied below the edge. the “slop” will tend to lower the angle. When you move the pressure point above the edge, the stone will rock over (pivot about) the edge and increase the angle. If you pay attention to the noise, you can actually hear a “click” when the stone switches from one line to another. I’ve measure differences between 0.45 and 1.05 degrees. Try it yourself.
This all drove me to convert all my stones to bronze bushings. I understand that Cliff Curry has a much easier fix.
The simple solution is to hold the stones at the bottom finger groove and try not to let your grip point go above the edge.
I’ve got some photos of this but couldn’t understand the new dialog box when I tried to insert them. I should have been paying closer attention when it was discussed. But then I have a terminal case of ADD and have never paid much attention to anything I wasn’t really interested in. Aaargh!
Hey man hope I can add some points to the very helpful info the other guys have posted above.
I have not had any issues w/ tightness of the clamp, but sometimes I do need to throw a piece of tape on the spine for added friction so the blade doesn’t slip (I pretty much always do this anyway so as to prevent any scratching from the vise). I can pick up the entire wicked edge and granite base by holding the knife handle, but I can rotate the knife in the clamp by pushing up and down if I try.
Some have put tape over the gap on the side of the vise to prevent abrasives from falling down onto the cam shaft… I haven’t messed w/ it so far.
I use the drop tip method only when I regrind a knife because I know that I set up the grind for an edge that is a true angle from heel to tip (or as close as possible). On pretty much all production knives I tilt the tip down because most all of them actually widen up at the tip and this will allow you to match the existing, yet changing, angle. I use a sharpie with almost every knife =)
Other note: I have found a consistent blade cant/tilt of the knife to the right whereas on the gen 2 vise it was always to the left. It is only about 1 degree so not a big deal, but other than that I haven’t had any issues. I am also using aftermarket steel jaw inserts if that changes anything.