<!doctype html public "-//W3C//DTD W3 HTML//EN"> <html><head><style type="text/css"></style><title>Re: tooling up for soundboard replacement</title></head><body> <div>At 9:10 PM -0500 6/12/03, Erwinspiano@aol.com wrote:</div> <blockquote type="cite" cite><br></blockquote> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#000040">   Hi Ron</font></blockquote> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#000040">  Beautiful plate and soundboard shot on the url. WOW!!!</font></blockquote> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#000040">  How are you turning the bolt in full depth without a head on it?</font></blockquote> <div><br></div> <div>Sorry Dale if I didn't explain it properly. Before fitting the dome-nuts-fitted-to-booker-rod into the iron plate, we use a piece of threaded booker rod with a nut welded to the top. This piece of booker has a section of its diameter ground away where it first enters the inner rim, so as to cut a slightly tight thread into the inner rim. This makes inserting the dome nuts and booker a lot easier so as to avoid damaging the chrome finish on the dome nuts.</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#000040"> & Would you mind clarifying this procedure?</font></blockquote> <div><br></div> <div>In the case of our 225 piano, the pin block is first fitted to the plate<font color="#0000FF"> (which has a flange on either side of the pin block)</font>. The plate and pin block are bolted together when the plate is fitted to the case. The plate and pin block is secured to the inner rim using long coach screws which pass through both the plate and pin block. We don't glue the pin block to the inner rim so that, if necessary, the plate and pin block can be removed from the piano as a unit when overhauling the piano at a later date. We adjust the height of the plate in the piano by shimming up or letting in the pin block ends, relative to the inner rim. The shims are tapered to ensure that the orientation of the pin block agrees with the final angle of the plate inside the rim. At the back of the piano a cap screw<font color="#0000FF"> (a bolt with a hexagon wrench recess in the head)</font> is fitted through the sound board panel and into the inner rim. This cap screw is responsible for setting the height of the plate behind the bass bridge. The cap screw is adjusted via the access hole which is drilled in the plate<font color="#0000FF"> (this hole is visible in the large image of piano no. 3 at</font><font face="Arial"><b>  http://overspianos.com.au/bkcl.html</b></font><font color="#0000FF"> )</font>. All setting of the plate height in the case is done with the set bolts wound down sufficiently to avoid contact with the plate. So the plate is adjusted using only three support points<font color="#0000FF"> (each end of the pin block and the cap screw at the back)</font> until all hitch pin fields are at a height which enables the down bearing to be fine tuned with various heights of rear aliquot blocks manufactured for the purpose<font color="#0000FF"> (in 0.5 mm steps from 4 mm to 7.5 mm)</font>. Once the correct height for the plate has been established, proper tapered hardwood shims are manufactured for each end of the pin block contact with the inner rim. The thread holes<font color="#0000FF"> (around the plate perimeter)</font> are then 'tapped' into the inner rim before fitting the dome nuts. After locking down the dome nuts, the set bolts are raised just until they meet the underside of the iron plate<font color="#0000FF"> (a dial gauge on a magnetic base is used for determining the exact point of the set bolt meeting the plate)</font>.</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#000040"> I"d might be interested in adapting this perhaps on certain  rebuilds.The plate holes on S&S & others are a bit big so I'm not sure how retrofits would work out.</font></blockquote> <div><br></div> <div>The S&S D plate looks as if a Baldwin style plate mount conversion would work with 1/2" bolts. I've just pulled down a 1962 Hamburg D for a rebuild. After pulling the plate we found that the board has collapsed in the second last treble section. There's plenty of crown out the back of the bridge, but the board is inside out between the bridge and the belly rail<font color="#0000FF"> (would anyone like to see an image?)</font>. I will be discussing a proposal, with the concert hall's house technician, of building one of our new sound boards into the piano, along with a curved bass corner cutoff, a back beam & set bolt in place of the bell<font color="#0000FF"> (which in this case had the drop bolt bent into a 25 mm offset to accommodate what appears to be an incorrectly drilled hole in the plate)</font>. I designed my own log style scale for Ds back in 1990. I'll certainly use it if the clients are OK with it, since the tuning stability and tune-ability has proven to be better than the OEM version<font color="#0000FF"> (I have re-bridged three Ds with this scale to date)</font>. I'm also considering a sound board cut-off out the back of the top treble section to rid the piano of a few acres of unnecessary panel out the back of the treble bridge. As has been our previous practice, we will be placing text in the piano to state exactly what we have modified, just to keep the dollar signs out of the legal-eagle eyes. Wouldn't want anyone to allege that we were 'Passing off' would we?</div> <div><br></div> <blockquote type="cite" cite><font face="Times New Roman" size="+1" color="#000040">. . . Also how do you cut that relief channel in the board so beautifully?</font></blockquote> <div><br></div> <div>We use an air driven die grinder which is mounted in a custom made mini-router style attachment. The die grinder is mounted directly over a corner of the base plate so that it can be used right in close to a vertical surface. I turned up a number of different diameter steel 'tyres' which fit over a ball bearing mounted above the half round cutter. The bulk of the material is removed by taking passes with the required diameter guide wheels, before hand blending the profile.</div> <div><br></div> <div>By the way folks, I am pleased to be able to tell you that our piano no. 4 will be playing by this coming Saturday. We are having an open day for local technicians to try it out against no. 3. Wal just got the last strings on today<font color="#0000FF"> (Sunday)</font> and I chipped it up to pitch this afternoon. Details of the new sound board design<font color="#0000FF"> (the first is fitted into no. 4)</font> can be released from Saturday December 13.</div> <div><br></div> <div>Best,</div> <div>Ron O.</div> <x-sigsep><pre>-- </pre></x-sigsep> <div><font face="Times New Roman" 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><font color="#000000"><br> _______________________</font></div> <div><font size="-2" color="#000000"><br> </font><font color="#000000">Web http://overspianos.com.au</font></div> <div><font color="#000000">mailto:info@overspianos.com.au<br> _______________________</font></div> </body> </html>