Dan had done a great post on the arched grind line, I call it the SWOOSH. Anyway I could never get it to work and after many frustrating attempts decided there had to be a better way at least for me there had to be a better way. I rough grind all my blades on a 2x72 and then it is off to the lap wheel to final grind and finish them. I consider my lap wheels the most important piece of equipment in my shop. Note : my lap wheels (disk grinders ) run at 1200 RPM are reversible and have 1 degree bevel on the face so the blade does not touch the wheel on the other side of centre. Anyway here is the process that I use and has worked for me.
Thanks Cal. I have a similar wheel, 1° bevel, reversible. About how thick do you take the bevel down to on the belt before going to the disc? I will give it a try. Dan
Maybe 50-60 thousands, depends if you left any ugly gouge marks from the 2x72. I usually rough grind with a 36 grit belt which can leave some pretty ugly marks.
I have a 1 degree beveled disc, so a few questions. So if center is flat and the disc slopes out to the outer edge...you’re carefully feathering the plunge in, as it makes contact on the outer edge, hence the ‘Swoosh!’ By the looks of the photo you are grinding edge down, and the disc would be running clockwise grinding the left side bevel. Okay so do you have to watch that tip like crazy because it’s flush on the center while you’re putting pressure at the plunge area on the outer edge of the disc? Or is the tip raised off center as you put pressure on the outer edge? Or Are you pushing across center so the tip starts lifting off on the other side? Just curious about the nature of the beveled disc...to date I have only used the flat disk for...well...flats lol! Final question, has anyone forgone the 2 x 72 and done this grind completely on a disc sander start to finish? I would imagine a jig set at the correct angle would make this easier. Anyway, thank you @FORGE for sharing this, and thank you @dancom for starting the discussion on this fascinating grind. *Thumb up* and Cheers