Often during grand regulation we remove and replace the cheek blocks repeatedly as we go through our procedures. I used to be in the habit of giving a moderately strong tap on the cheek block with my fist, once it was in place, to make sure that they were properly seated.. that is, until Stephen Knupfer of Steinway Hamburg pointed out that this common gesture has the effect of bending the guide pin into a downward angle after a number of repetitions. Then, of course, the pin will rattle in shift position. Giving the left guide pin a half turn once it's bent just inverses the problem and makes the action tend to stick in shift position. For the right guide pin the situation is roughly the opposite: if it rattles at rest it could stop at shift, and given a half turn it can rattle in shift position but not at rest, all depending on the regulation of the cheek block bracket. The best solution is, of course to replace the guide pin. The moral is, don't bang on the cheek blocks, set them in politely. I've been stunned to see our piano movers heft a grand onto a stage by flipping it upside down (i.e. plate and string side down towards the floor)! I don't imagine that this does much for the guide pins either. Jerry Anderson Paris
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