<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body bgcolor="#ffffff" text="#000000"> The sharps at rest should be at 1/2" above the naturals. If you increased the dip to 1/2", the sharps would bury in the naturals which is incorrect. That's the reason for .390" ±. I think spinets may have a little more dip. Key dip is an independent variable. This is what an experienced pianist expects so we start with that. The dependent variable is hammer blow distance which should be sufficient to allow the jack to clear the hammer butt buckskin by about 1/32". If the hammers have been filed such that the blow distance has increased, the solution is to shim under the hammer rest rail to decrease the hammer blow and not change the key dip if it is correct. Tom Cole <a class="moz-txt-link-abbreviated" href="mailto:mps@usol.com">mps@usol.com</a> wrote: <blockquote cite="mid200704090027.l390RYrh025980@www.usol.com" type="cite"> <pre wrap="">I have an old Hackley upright in which the hammers have probably been shaped a couple of times. I have had no problems with the regulation on the instrument. However, I think that I read someplace that the key-dip on this could be adjusted as low as 1/2". My question is if I do adjust the white keys to a 1/2" key dip, how would I measure the black keys so that they also have the same amount of dip? Also, what are the deciding factors of exactly how deep to set this key-dip? Thank you Mark D. Montbriand </pre> </blockquote> </body> </html>