Raise the grinder or lower the jig as Eddie does. Or forget it and freehand, using the tool as its own jig. Six versus eight comes up in grinders all the time. If slow speed is better, which is another bit of grinding wisdom, then 6 should be better, because the speed's slower. If only there weren't so many famous names brought up endorsing 3450, there would be no problem.
We all know that beautiful edges are produced by honing under hand power at slow speeds, just as we know that beautiful cuts are made by carving gouges at equally pathetic slow speeds. So why do we say faster speed at the lathe makes smoother cuts and slower speed at the grinder makes better edges?
Of course 1' stones are available for 6" grinders, so that's no problem. With only one point of tangency possible at a time, never did matter on a curved edge. Some say the wood knows the difference between 0.002 and 0.003 air gap in a hollow grind, but all the pieces I've asked have given me a blank stare and ignored me as if I were crazy. I don't think they can tell whether the bevel was made by a 6 or an 8 or any of the in-betweens.
Guess the summary goes "do what produces best results for you." The reproduceability afforded by the jig is highly regarded by many. But then so are slower speeds, higher speeds, shallow and deeper grinds. I personally think it's a case of micrometer measurement and crayon marking. I can't bring a perfect edge to the wood freehand any better than I can bring the edge to the stone. OTOH, I don't do worse, either. Both involve A-B-C with spinning objects.
