Dale, I must agree! Your block method is very accurate and has never failed me. I will at times do a check based on measurements, but as you can see, based on the length and different inputs on this tread, I'll stick with the KISS method. Al - High Point, NC On Sep 22, 2012, at 10:00 PM, Dale Erwin <erwinspiano at aol.com> wrote: I had to know, ya know?...so I went to the shop and performed my own first test based on the parameters below in my previous e-mail. The initial action ratio reading using the quick Erwin action ratio block/tester shows a 5.5 action ratio on a Stwy B action from the last decade. The action is in good shape and regulated. 6 mm of key dip accounted for 33 mm of hammer rise. In the next test to insure only 10 mm of dip I removed the punchings and replaced it with hard card board one. So no punching compression at all. Ok Jason? I used digital calipers to measure dip as accurately as possible at 10 mm. the key was depressed 10 mm and measured;... total hammer rise. Tada !....55 mm So the action ratio is 5.5. So this is only one check & I was more microscopic than usual. So for my money, I'll stick with the quick and simple method of using the action ratio tester first and then measuring of the leverage. The beauty of crunching the numbers is that the leverage changes become more specific. Usually its the knuckle placement, capstan location or changing both in order to achieve a specific reasonable action ratio. Beyond that its a new key set with a change in leverage. Try this yourself Dale Dale Erwin R.P.T. Erwin's Piano Restoration Inc. Mason & Hamlin/Steinway/U.S. pianos www.Erwinspiano.com Phone: 209-577-8397 -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://www.moypiano.com/ptg/pianotech.php/attachments/20120923/71fb8dd7/attachment.htm>
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