Hi JD How can this difference be delt with by raising the front of the flange ? I havent done the trig to figure it out... but off hand seems like to gain 1 mm spread by rotating the flange on its 23 mm arc you'd need quite a raise. Perhaps I am in error here. In any case you are not repositioning the centerpin horizontally so much, which means the knuckles horizontal location will be basically unchanged... which means the jack will still have to be angled inwards just about as much to meet the knuckle core. Grin... puzzle for the day ... I suppose I'm going to have to dig out my math books agin... :). How much arc travel does the hammer flange center pin have to travel upward and away from the whippen flange center to increase its spread by 1 mm ? Cheers RicB The difference between 23mm centre to rail-midpoint on the old flange and 24mm on later flanges can be allowed for by packing the top of the lever flange, as has been discussed, without affecting much the behaviour of the action, but there is no way a 10mm roller can be used rather than the original 9mm roller without severely interfering with the geometry of the action. JD
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