At 5:36 pm -0800 14/2/07, Jurgen Goering wrote: >...For the purposes we are talking about, the velum should be no >thicker than 0.15 mm, otherwise the damper underlevers tend to float >just a little. I have this information from an experienced tech in >Germany who has written an article on replacing the Blthner back >action velum hinges. I had a look today at the damper bodies of an old Kirkman from the days before they switched to a centred flange. Blowing up the original picture and roughly measuring the visible slot on the computer, it looks as if it is something less than 0.2mm, which would include a small amount for the glue lines. I think I have a few of the hinges to replace, so I'll make a point of measuring the old vellum with the micrometer when I do this. I'll be taking a set of Blthner strings to a colleague tomorrow and it's quite likely his damper action won't be perfect, so I may get a chance to measure these too. JD -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070216/66b4b87f/attachment-0001.html -------------- next part -------------- A non-text attachment was scrubbed... Name: P2A9A274A 3.png Type: image/png Size: 263 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/20070216/66b4b87f/attachment-0003.png -------------- next part -------------- A non-text attachment was scrubbed... Name: P2A9A274A 4.png Type: image/png Size: 214750 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/20070216/66b4b87f/attachment-0004.png -------------- next part -------------- A non-text attachment was scrubbed... Name: P2A9A274A 5.png Type: image/png Size: 80721 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/20070216/66b4b87f/attachment-0005.png
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