This one that is available is a little different than the one I used years ago in the body shop.In the old days an adjustable grinding disc cutter was used to trim down the worn edge of a grinding disc might someone have one surplus to there current needs I would like to buy one .John.
Unless you have many to do, I use an old pair (Chinese made) of aviation snips and do it by eye. The uneven edge actually helps for some reason.
Cutting "V" notches or cutting the disc in the shape of a triangle or square was not meant to provide a 'fresh' area of grinding material but gave flexibility to the disc that allowed it to conform to curved or convex surfaces. (did that back in the 50's)Somewhere awhile back I saw a tip in a magazine that said to cut "V" notches in the edge of the disk. Similar to your method.
Don't know what kind of discs you are talking about but the autobody surfacing discs that are being talked about generally have to have about a half inch or more removed to get to fresh material.If you are careful and practice for awhile, try holding the disc against a COARSE bench grinder wheel.
Cleans the edge up just like new.
Don't know what kind of discs you are talking about but the autobody surfacing discs that are being talked about generally have to have about a half inch or more removed to get to fresh material.