This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment That's exactly what I have done as wel Dave. Approach also from Del. = Works great. That way also, when rescaling, you are not restricted by = the original speaking lengths and bridge shape. Terry Farrell ----- Original Message -----=20 From: David Love=20 To: Pianotech=20 Sent: Friday, October 24, 2003 6:26 PM Subject: RE: Make a soundboard--Measurements The bridge I just did I ended up laying out from scratch rather than = trying to follow a pattern, an idea I got from Del Fandrich. I found = this to be easier and more accurate since I was rescaling and making = slight alterations to the speaking lengths. It also allows you to avoid = duplicating mistakes on the previous layout. The method I used was to = first mark on the plate the center string locations on each hitch pin. = I used a dummy tuning pin with a string attached (Mazzaglia) which I put = into the center tuning pin hole on the plate and wrapped the string = around the corresponding hitch pin. Eyeball the string in a straight = line through the capo (or from the agraffe) and over the bridge and make = a pencil mark right under the string on the front and back of the = bridge. Take a small straightedge and draw a line, move to the next = one. When you are done look at the overall spacing and make any co! = rrections to get it looking even. From there measure your speaking = lengths and mark on the line the front center pin location. Using one = of several three hole punches I also got from Mazzaglia (depending on = spacing), mark you pin locations. Measure from the front row to the = back row at whatever pin spacing you are using and mark the back row = center pin. Using the three hole punch, mark the back row. At that = point, if you are going to paint graphite on the bridge to, do it then, = it makes it much easier to see where you are notching if your eyes = aren't as sharp as they once were, like mine. Drill your bridge pin = holes. Then mark the side of the notch at 90+ degrees (whatever you = use, I use 93) off the front pin line. I use a small piece of mylar cut = at the proper angles which a lay along the pin line. Look over your = markings to see that they are evenly spaced. Cut along the line with a = small saw to unif! orm depth (don't overshoot the hole, use a chisel for = that last bit). Then cut your notches. =20 I've gone beyond my point a bit, but I found that laying out the = bridge from scratch eliminated worrying about how precise the pattern = was and trying to copy it. I still make the pattern because it gives me = the location for screws in the top of the bridge when I am gluing down = the new cap (on an old board), and lets me know generally where I should = cut my bearing points, and out of habit. But laying out new gave me = better results and it may even have been faster. =20 David Love davidlovepianos@earthlink.net ----- Original Message -----=20 From:=20 To: pianotech@ptg.org Sent: 10/24/2003 8:37:18 AM=20 Subject: Make a soundboard--Measurements In a message dated 10/23/2003 11:19:33 AM Pacific Daylight Time, = michael@gambles.fsnet.co.uk writes: Hello RicB It would be very important to set down the criteria for = measurement of soundboards. That must be the starting point. If everyone who = wants to partake in this research takes all the stipulated points for = measurements then there might be some realistic steps taken. Be sure to make = the names of these points international!..;-) Regards Michael G (UK) -----=20 Michael, Ric Glenn Well, Michael, I don't know if you'd call it research. List you = proposed on measuring things & observations are really probably already = outlined in the journal & are just some of the measurements all = soundboard installers use.=20 I.E. Measuring string heights, Plate height, bass & treble 88, = mark the front corner of the plate & measure the distance fore & aft in = mm to the case side. These locate the plate. Note any odd things about = the bridges. I.E. inadequate side bearings, strings not going straight = to the hitch pins, funky notching angels you don't wish to duplicate. = Measure down to the top of the plate at the bosses. This allows you to = set the height of you dowels later if you use them. Measure the string scale. If funky after unstringing measure = string lengths & crunch the no.s. Often note 88 is too short for decent = tensions in the last section. You may want to move the bridge as on many = older 1800s S&S grands. Note the angle of the bridge top to the board. I don't often do = this but every piece of info can be helpful. (Observation)Look at the thickness of the board thru the action = cavity at the belly rail & see how it tapers. (Mental note) Observation) Any crown left any bearing left. Does the bearing = string still touch the bridge now the strings are removed. is the bridge = below the string plane? Pull the plate. Pull the bridge pins. make a GOOD pattern noting = hole side notch cut. Use a bridge pin bit drilled straight down thru the = bridge to locate the mylar pattern. Place mylar (I use 10 mil) over = bridge and tap no. 6 pin thru mylar. It make a cleaner hole than = drilling thru it. I always measure at least first and last string lengths on the = long bridge & bass bridge.=20 Very important: Bridge location markers. I do this 2 ways. I drill straight down. straight is very = important thru the top of the bridge at not 88 with a 3/16 bit and thru = the board & into the belly rail. This will help locate the top of the = bridge very precisely. I also do the same in the tenor end, drilling = into a beam if possible. I also take direct measurements with a metric = ruler to the side of the case at each end of each bridge.=20 I also measure the distance from the no. 88 bridge pin hole to = the side of the case & stretcher. This eliminates the possibility of = getting pattern located wrong. There are other ways. Rebuilders please = chime in. Drill out dowels remove treble cap screws. Now the fun part. It's = time to knock the board out Any body tired yet? More later. going to work Later--Dale =20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... 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