On the contrary, the jack top does have friction-related resistance to moving across the hammer butt leather on an upright. You can especially feel it while pressing the key down very slowly - it is not nearly as prominent as on a grand, but it is there. A nice new piano with a lubricated jack tip will have little resistance. An older piano may have more. The hammer butt spring is pushing the hammer (and hence the hammer butt) backwards and the key is pushing the wippen (and hence the jack) upwards and the let-off button and key movement is causing the jack to rotate and the jack tip to travel across the small section of hammer butt leather. Aftertouch is NOT the feeling of resistance. Aftertouch is the distance the key travels from when the jack JUST kicks out from the hammer butt and the hammer lets-off to where the key bottoms out on the front rail punching. The "after" part of the word "aftertouch" means "after let-off". I find the easiest way to measure aftertouch is to press the key down slowly paying close attention to the let-off event. The jack should move out from under the jack and you'll notice that the hammer travel is no longer being supported by the jack/key travel. Then there should be some small amount to key travel after the let-off event. That small key travel is aftertouch. We want to measure that small amount of key travel. Get an assortment of thicker front rail punchings and put some on the test note, on top of the felt front rail punching (thus limiting key travel a little bit). Maybe start with an 0.025". Now slowly push the key down and again closely observe let-off. Does let-off occur? Do you have enough key travel? If let-off still easily occurs, you have more than 0.025" aftertouch. If let-off doesn't occur by the bottom of the keystroke, you have less than 0.025" aftertouch. Experiment with different thickness punchings until you can press the key down with light/moderate pressure and see that the jack does not move out from the butt, but with a little more downward pressure with the key at the end of its keystroke, then the jack will just move out and the hammer falls back until the backcheck catches it - the thickness of test punchings you have on top of the felt front rail punching is the aftertouch distance. Be consistent with your key pressure. Some folks use a weight to be sure to apply consistent pressure. When I regulate aftertouch on a non-performance piano (like a piano in a home that hasn't been regulated in 50 years and likely won't ever again), I use a "go - no-go" aftertouch gauge. If, say, I'm targeting an aftertouch of 0.035", I will have a stick with front rail punchings glued on each end. One end will have an 0.025" punching and the other will have an 0.045" punching. The punchings will have a slot on the ends so that I can just slip the gauge in onto the pin (I don't have to lift the key). Then I simply adjust front rail punchings so that the not does not go through let-off with the 0.045" gauge end inserted onto the front rail key pin and the note easily goes through let-off with the 0.025' end inserted. Then I know aftertouch is somewhere close to 0.035". Or, on the other hand, I could be wrong. My fingers are tired from typing. I'm going to stop now. Terry Farrell ----- Original Message ----- From: "John Delacour" <JD at Pianomaker.co.uk> >>Maybe my understanding of Aftertouch is not right. I understand it to be >>the feeling of resistance (like a shelf that 's about to fall) that the >>player feels just when the jack is about to flip out..Is that right? > > That might be a symptom in a grand but there is no such thing in an > upright, which is what you're asking about, because there is no resistance > to the jack escaping from under the notch. SNIP
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