... but why? sure gears - like on guitars - would be probably too big and wouldn't fit[0], right? (and/or too expensive) but they could put the knobs on the to

... but why? sure gears - like on guitars - would be probably too big and wouldn't fit[0], right? (and/or too expensive) but they could put the knobs on the top of the peg ... the gear could be inside, and as it is rotated it could push out small cams or "break pads" to make a wedge[1], same friction would make sure the pin stays in place and does not rotate, but no need for the hammering. of course probably because of acoustic this or that having solid pins is "much" better? [0] https://en.wikipedia.org/wiki/File:Piano_tuning_lever_that_is_on_a_tuning_pin_with_hammer_striking_a_string_in_an_acoustic_grand_piano.jpg https://en.wikipedia.org/wiki/File:Piano_tuning_lever_that_i... [1] https://en.wikipedia.org/wiki/Molly_(fastener) https://en.wikipedia.org/wiki/Molly_(fastener)