Hi, The real question is, why aren't all balance pins oblong at the top? With this arrangement, button and mortise can be mortised with the same tool, at the same time. Not only that, the number of doglegs in a key can be reduced since the buttons aren't so compromised in width, and therefore lengthening their working grain. Seems to me the extra cost of a 0.147" shank, 0.089" tip balance pin would offset the cost of keyplank layout, button placement and button trimming, where bushing would be directly on each key - before or after sawing. Yes, the oblong shape of front pins lend them to adjustment when bushings become worn - however, this only compounds the original problems of misplacement. Round balance pins, similarly misplaced, exhibit deformed bushings (perhaps more, due their tighter radius and smaller travel) - ideally they should be positioned to intersect a variable touch point and fixed jack or capstan position, according with the leverage required by the action. I've been replacing well-placed oblong-tip balance pins with round wherever I find them. Like many other antique features I wish they were more available. I've made a tool for this replacement if you're interested. Disgruntled, Clark
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