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I try and keep my finger joints square for aesthetic reasons, but the depth of the joint is what is relevant to the thickness of material. If the depth is a hair too much or too little the piece can still be assembled. On the other hand, a hair too much or too little will multiply on a row of joints and what fits at one end by the time you are ten fingers down they could be 180 degrees out of phase and the piece cannot be assembled. So this needs to be kept in mind when modifying a working design
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