<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: [pianotech] Agraffe Washers</title></head><body> <div>Hi all,</div> <div><br></div> <div>Agraffe alignment is always a pain without some facility to make custom thickness washers. I don't find OEM washers to be very useful most of the time, because the thickness required invariably isn't the thickness of the washers available.</div> <div><br></div> <div>For those who have a lathe, it is easy to turn up custom washers with a sharp parting tool. A narrow parting tool can be used to part off washers to exactly the thickness required. Wal and I do the agraffe fitting in our shop. Wal fits them to the plate while I work the lathe producing the washer thicknesses that he calls for after the first nip-up of each agraffe which requires shim adjustment.</div> <div><br></div> <div>The procedure for turning is;</div> <div><br></div> <blockquote>1) Turn up a sleeve of approx. 80 mm in length to the OD and ID required (use either free machining brass or SAE 1214L as working stock)</blockquote> <blockquote><br></blockquote> <blockquote>2) Sharpen a narrow width parting tool (I use a 2.5 mm wide cutter - don't use throw away cutters - they are not sharp enough)</blockquote> <blockquote><br></blockquote> <blockquote>3) Make a parting cut of minimum width, such that the tool is cutting with both outside edges of the tool in the stock.</blockquote> <blockquote><br></blockquote> <blockquote>4) Advance the cutter down the bed towards the chuck, using the compound slide, by the width of the parting tool plus 20 thou, noting the total number of thou the compound slide was advanced.</blockquote> <blockquote><br></blockquote> <blockquote>5) Measure the thickness of the resulting washer with a micrometer. You can now calculate the effective parting-off loss due to the cutter width. It will be, the amount the cutter was advanced towards the chuck minus the thickness of the test washer.</blockquote> <blockquote><br></blockquote> <blockquote><font color="#0000FF"><i>The reason for going through this five step procedure before making the custom washers is to determine exactly how much stock is lost for each advance of the cutter from one washer to the next. Lets say that the cutter loss is determined to be 95 thou (our 98 thou [2.5 mm] cutter will become narrower as we sharpen away more of the tool). Knowing this we can produce a 2 thou washer by advancing the cutter 97 thou down the bed, then parting off. For a 5 thou washer we advance the cutter another 100 thou from where the last part-off was made. Using this procedure, we can use up the entire 80 mm of sleeve, losing only the cutter width between each successive washer.</i></font></blockquote> <blockquote><br></blockquote> <div><br></div> <div>You can now part off washers down to a couple of thou in thickness up to whatever you require. Don't worry about the thinner washers curling up a bit when they are parted off. They'll soon flatten out when they are compressed between the agraffe and the iron plate counterbore.</div> <div><br></div> <div>This might sound like something of an effort, but if you fit most of the agraffes using a power screwdriver to determine those agraffes which can be fitted without the need of a washer, you'll usually only have about 6 to 10 agraffes which require a thin washer the get the remaining agraffes to the correct position for pre-loading to alignment.</div> <div><br></div> <div>Hope this helps.</div> <div>Ron O.</div> <div><br></div> <div><br></div> <blockquote type="cite" cite>On 3/12/2012 10:38 AM, Nicholas Gravagne wrote: <blockquote type="cite" cite>List,<br> <br> Am I not remembering right, or was there a time past when 0.007" thick<br> agraffe washers were available? Pianotek carries 0.020" and 0.012",<br> while Schaff carries 0.010".</blockquote> </blockquote> <blockquote type="cite" cite><br> <br> Steinway sells 0.021" and 0.030", according to the 2011 parts list, but I don't remember any 0.007" from anyone. Maybe John Ford or some such, now long gone. But I almost never use them, so I'm not much of an information source there.<br> <br> Ron N</blockquote> <div><br></div> <div><br></div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font size="+1" color="#0000FF"><b>OVERS PIANOS - SYDNEY</b></font></div> <div><font color="#000000"><i>   </i></font><font color="#0000FF"><i>Grand Piano Manufacturers</i></font></div> <div><font color="#000000">_______________________</font></div> <div><font size="-2" color="#000000"><br></font></div> <div><font color="#000000">Web http://overspianos.com.au</font></div> <div><font color="#000000">mailto:ron@overspianos.com.au</font></div> <div align="center"><font color="#000000">_______________________</font></div> <div align="center"><font color="#000000"><br></font></div> <div align="center"><font size="-1" color="#0000FF"><i>A web page with images of recent work and almost-audio-CD quality mp3 sound files of the Overs piano can be found at;</i></font></div> <div align="center"><font size="-1" color="#0000FF"><i>http://overspianos.com.au/more_info.htm</i></font></div > <div align="center"><font size="-1" color="#0000FF"><i><br></i></font></div> <div align="center"><font size="-1" color="#0000FF"><i>So put on your headphones, plug them into your freshly restarted computer and sit back to over 20 minutes of pure piano.</i></font></div> <div align="center"><font color="#000000"> _______________________</font></div> <div align="center"><font color="#000000"><br></font></div> </body> </html>