Craig, Below is a post from Israel Stein that I saved from a previous discussion on the CAUT list. Maybe it'll help. Good luck. Avery >I need to do some regulation work on a Steinway upright. The sostenuto does >not work quite right, (it holds some dampers but not all) and another >technician told my friend that it could not be fixed (I think he didn't know >how to fix it, or didn't want to bother). I assume that it works like a grand >sostenuto, but I haven't been able to find literature or reading on the >matter, in either my Potter course manual or the Reblitz. > >Does anyone have the regulation sequence for a Steinway upright? Specifically >on the Steinway sostenuto? I will gladly pay for postage and copying if >someone has it handy. I have regulated umpteen verticals, but never one with >the sostenuto mechanism. > >Sincerely, >Craig Deets **************************************************************************** Date: Sun, 10 Aug 1997 09:14:35 -0700 From: Israel Stein <custos3@ix.netcom.com> Subject: Re: Help with Upright Steinway Sostenuto Sender: owner-caut@ptg.org David, Steinway publishes a technical bulletin. The section on upright sostenuto regulation is quite thorough and helpful. It is Steineway Technical Bulletin Volume II #1. It applies to all current upright models - K-52, 1098, 45 - and both types of upright sostenuto - felt and neoprene tabs. Sounds like you have the felt tab model. I've used the method in the Steinway bulletin back when I worked full time for the Boston Steinway dealer, and we got occasional mis-regulated sostenutos delivered. (No piano was sold or even shown to anyone until the shop gave it a clean bill of health. This dealer takes his prep and service obligations quite seriously...) Briefly, the idea is to regulate all sostenuto tabs in as straight a line as possible both vertically (by screwing them in and out) and in the backward-forward plane (by bending the wires). This adjustment is done on the bench, with the damper lift rod wedged up so that the dampers are approximately in the position they are when sitting on the strings. Needless to say, the dampers need to be in pretty good regulation (both to key and to pedal) for this to work. You then put the action in the piano, and adjust the position of the sostenuto rod and its rise so that it functions properly. You remove keys #3, 26 and 49 before replacing the action in the piano, so you can see what you are doing in the most strategic places. Use keys #2, 25 and 48 as your guide keys. Now, some specs: The sostenuto rod lip at rest should be at about 40 degrees pointing upward towards the wippen flange pin. Adjust this by shortening or lengthening the connector rod from the trap lever to the sostenuto rod - it has threads and nuts for this. The lip of the rod should be 1/16" below the felt tabs. Adjust it by shimming the rod brackets up and down on the keybed. Looking at your test keys, make sure that the rod lip engages the tab on the keys by a minimum of 1/32". If not, adjust the position of the rod back to front or up and down as needed. Now, try the sostenuto on each key individually. If some don't work, you'll need to adjust their tabs individually on the bench, by trial and error. Adjust the amount of damper rise with sostenuto by moving the (sostenuto rod) brackets backwards and forwards. That's a synopsis. Call Steinway Tech Services and get the bulletin. In fact, get all of them - they should have plenty on various topics. If you are going to be getting referrals from a Steinway dealer who doesn't give you any backup, no sense making yourself look bad. New Steinways do need a lot of prep (I spent close to 2 years doing it for a dealer who did back us 100% - even when Steinway disagreed!) Oh, about your squeaky sostenuto rod teflon bushing - I came accross a few of those. Sometimes the bushing can be damaged - Steinway sells replacements, and the replacement is quiet. Sometimes, the bracket is too tight (sounds like you did that when you bent it). Just throw away the teflon and replace it with good ol' bushing cloth. It works just fine... Israel Stein, RPT
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