Discussion Posts

  • Posted in: Pianotech

    Hi Mike: I downloaded the online version of the directory.  They are from last year.  Two PDF's,  One is alphabetical, the other is also, but by chapter and region.  I'm attaching the files.  I also would like a printed version, but with these files you ...

  • Posted in: Pianotech

    Nearly every day I have a need to find information on a member of PTG.  The former printed directory was so handy and useful that I rue the day it was decided to cease publication.  Yes, I understand the reasoning:  Go Green, save trees, it was costly, ...

  • Posted in: Pianotech

    Nearly every day I have a need to find information on a member of PTG. The former printed directory was so handy and useful that I rue the day it was decided to cease publication. Yes, I understand the reasoning: Go Green, save trees, it was costly, ...

  • Posted in: Pianotech

    Sort of.  What I'm saying is that increases in bearing change the stiffness of the assembly which has tonal implications in terms of impedance.  There is a point of diminishing returns, of course.   I don't think the change goes to zero but graphically ...

  • Posted in: Pianotech

    Let's try that again... David L< But if you notice that reducing downbearing has an effect that means that increasing it does too. This  statement  needs clarification, which is the point of my post.  It implies, as stated, DB changes spring function...true...and ...

  • Posted in: Pianotech

    Jim That's exactly what I said.  Read it again.  It depends on your starting point.  But the fact that you've compressed the board to it's maximum doesn't mean that the tone wasn't changing along that continuum until it wasn't changing any more.   If ...

  • Posted in: Pianotech

    The plate is strong, but its also flexible. Just observe what happens before and after with the Steinway Bell. The plate flexs up. The whole point of the bell is to stop that upward thrust to provide tuning stability to the treble.  Notice the nosebolts ...

  • Posted in: Pianotech

    David L<But if you notice that reducing downbearing has an effect that means that increasing it does too.  Not necessarily. Reducing DB most often has an effect when the linear spring has been overloaded, and the spring is no longer being allowed ...

  • Posted in: Pianotech

    I have just ordered a set of the size that is not available from PAL sound. I guess I'll have the answer to your question shortly. ------------------------------ Floyd Gadd Regina SK 306-502-9103 ------------------------------

  • Posted in: Pianotech

    James, Around 10 or 15 years ago, I changed the brackets in a Knabe branded Young Chang that was supplied by Piano Disc. It's probably the same model as yours. At that time I was able to get the brackets from Piano Disc, and they even compensated a pittance ...

  • Posted in: Pianotech

    If I had encountered what Jim did upon restringing, I would have simply said: "Well, I guess I was deceived again...the board's flat. So my next step is...can I improve it?" Pwg ------------------------------ Peter Grey Stratham NH 603-686-2395 pianodoctor57@gmail.com ...

  • Posted in: Pianotech

    The latest catalog show action brackets for YC and Weber grands . Has anyone used them and how did they fit as well as how much work did they require to replace the expanding/crumbling old brackets ?  I ordered 4 of the smaller size from Pal-Sound because ...

  • Posted in: Pianotech

    I think the back posts and bracing serve mostly to stabilize the rim and belly rail, not to support upward or downward movement of the plate.  The nose bolts are anchored to the bracing but the upward or downward forces are relatively small   The forces ...

  • Posted in: Pianotech

    Dave, Important observation. Perhaps some pianos have no deflection while others have upward or downward deflection. The substantial back posts and beams serve some purpose. Where is St. Fandrich when you need him? ------------------------------ ...

  • Posted in: Pianotech

    Hi Fenton, the blood was actually on the hammers just below where the knot was formed. ;). Good eye about the photo, though. There is an explanation coming out in next month's journal.

  • Posted in: Pianotech

    Dear Matteo, I'm very grateful for the work that goes into our publication, the technician likely had 90 seconds before the concert. At least there is no blood on the plate. Fenton Virus-free. www.avg.com

  • Posted in: Pianotech

    I appreciate Geoff's post, and would like to add that in their own way, as musical instruments, Viennese pianos from their later period, like this one, stand on their own merits as fine musical representatives, and should not be compared to today's pianos ...

  • Posted in: Pianotech

    Hi Fenton. I took the shot. I did not make the knot. And even though the knot was done well, I took the shot because the wire on the pin was overlapping the coil. Meaning, funny to do the work to make a nice knot, but not spend the time to get the ...

  • Posted in: Pianotech

    I ran across one of these from late 1870's, almost identical, at a high school in 2018. Posted pics and asked for feedback here. Received a lot of information and interesting opinions about what it was, what to do with it, etc. Here is that thread... ...

  • Posted in: Pianotech

    Jim, I would agree with that.  I have a couple of questions though. 1) How did the piano sound overall prior to teardown? 2) Were there any specific "problem areas" you isolated ahead needing investigation? Pwg ------------------------------ Peter ...

  • Posted in: Pianotech

    Not sure what that means. If you remove the cap screw and turn down the nose bolt the plate will not follow it down ( assuming the bolts are set neutral to begin with). To pull the plate down to the bolts you will have to tighten the nose bolt caps. On ...

  • Posted in: Pianotech

    Jim wrote " the only point of DB is to assist the termination at the front pin." i don't agree with that. DB compresses the soundboard. Since it is a non linear spring that stiffens the assembly and affects impedance. The compression also loads the ...

  • Posted in: Pianotech

    Sorry.  Not sure why they posted "sideways". ------------------------------ Timothy Edwards Beckley WV 740-517-7636 ------------------------------

  • Posted in: Pianotech

    Ran into this yesterday.  Badly cracked pinblock.  Several soundboard cracks.  It seems to have what I would describe as a "bridge cap" instead of the usual pressure bars or agraffes (some cracks).   s/n OPG420?  (I think)   Action reasonably functional, ...

  • Posted in: Pianotech

    Blaine, If you look under a lot of plates, you will often see a gap between the shoulder of the nose bolt and the plate bottom. Indicating the plate deflection is either neutral or upward. Pressure on the nose bolt screw can also be high, if you try ...

  • Posted in: Pianotech

    David S... NET DB is simply equal to the sine of the included angle (front and back added...ie the composite angle) * string tension. It doesn't matter whether the front and back are equal. Only thing that effects the actual DB force is the composite ...

  • Posted in: Pianotech

    OP = Original Post Alan ------------------------------ Alan Eder, RPT Herb Alpert School of Music California Institute of the Arts Valencia, CA 661.904.6483 ------------------------------

  • Posted in: Pianotech

    No.  The cap nut on a nose bolt is usually brass and only knurled to be installed by hand.  The plate bends downward into the back or under belly beams.  This should increase pressure on the soundboard. ------------------------------ Blaine Hebert Duarte ...

  • Posted in: Pianotech

    Like David S., I'm not any sort of belly man and may be off base or not even on the playing field, but.  In an earlier thread, David Love posited that the reason strings continue to go flat as one begins a pitch raise below is that the plate and ...

  • Posted in: Pianotech

    I use a bubble gauge. ------------------------------ David Love RPT www.davidlovepianos.com davidlovepianos@comcast.net 415 407 8320 ------------------------------

  • Posted in: Pianotech

    The plate doesn't deflect downward, it deflects upward. If the bridge is deflecting downward then the plate must be deflecting upward. How would you lose downbearing when taking off tension?  It's just the opposite. ------------------------------ David ...

  • Posted in: Pianotech

    I've never figured out an accurate way to measure the change in crown directly I used to measure the free space between a bridge top and strut before and after de-stringing. Jim, I also would want to know bearing after de-stringing, did it change? How ...

  • Posted in: Pianotech

    Note: I am not a rebuilder! The function of the nose bolts and beams of a grand piano is to support the strong downward deflection of the plate.  I have worked on an antique grand that did not have sufficient plate support and the plate collapsed (I ...

  • Posted in: Pianotech

    In this scenario did you measure the change in the downbearing with the tension off the strings?   When I destring a board I first measure the DB with tension. Then when I take down the tension I leave a string in each section with tension and then ...

  • Posted in: Pianotech

    The downside of high positive front bearing and negative back bearing is that you can cause the bridge to rotate forward (bridge roll) as it's pressed down from the front and lifted from the back. That can cause some distortion of the panel in an extreme ...

  • Posted in: Pianotech

    I don't believe I was arguing on behalf of angular equality.  Rather, wondering if a configuration that acheives a target moderate amount of NET downbearing by combining grosser amounst of positive front and negative rear is a) functionally the same as ...

  • Posted in: Pianotech

    The tech obsession with angular equality of the front and back segments, I find, emprically, to be spinning wheels in the sand. It has no meaning, in my experience, if it is even being accurately measured. Efficiency of front termination is very important, ...

  • Posted in: Pianotech

    Hi Jim - Skipping over my particular obsession with front termination issues for the moment, I also use a Lowell gauge in a more semi-traditional way, comparing SL to HL segments, but relying upon my  other methods to ascertain negative relationships ...

  • Posted in: Pianotech

    I made a couple years ago, but no longer have the dimension for the 5-6 holes. It's super easy to do with some thin plexiglass and a drill press. ------------------------------ John Formsma, RPT New Albany MS Live not by fear or lies. Over 3,400 Americans ...

  • Posted in: Pianotech

    David, Yes, I meant strung...autocorrect.  There are two basic reasons I don't attempt to measure DB in the string state:  1) I have dealt with too many "mis-diagnoses" due to the fact that it is a dynamic system and what "appears" to be...ain't 2) ...

  • Posted in: Pianotech

    <"misleading unto bogus" - can you describe how so? This was the content of the OP. Bogus means, when loaded there is DB, and loaded board is flat. Then when unloaded, the board remains flat...no crown recovers. This does not physically makes sense, ...

  • Posted in: Pianotech

    I'm definitely going to try the stretcher before I take off a leg! Thanks, everyone. I'll let you know what happens.

  • Posted in: Pianotech

    There is a 2007 AF 215 here at the shop, but no scaling notated on bridges or plate.

  • Posted in: Pianotech

    Does anyone have the Stringing Scale for an August Forster Model 215? ------------------------------ Mike Ello Richmond TX 281-633-0622 mike@ellopianoservice.com ------------------------------

  • Posted in: Pianotech

    I see it a little like a diving board: when you put pressure on it with weight (compression), its inherent elasticity is flexed and resultingly under tension. The SB though, being glued on all edges, appears to have less give with zero weight or ...

  • Posted in: Pianotech

    Why, when I look at the cover of the new PTJ do I critique the entire repair? A bend in the wire, the knot bearing again a neighboring coil, 4 coils instead of 3, overlapping coil. I'll stop there, so easy to critique from my easy chair. Fenton ...

  • Posted in: Pianotech

    Not sure that 'tension' is what you mean.  'stress' or 'compression' perhaps, but, even then, where would that come from without downbearing? ------------------------------ David Skolnik [RPT] Hastings-on-Hudson NY 917-589-2625 --------------------- ...

  • Posted in: Pianotech

    Hi Susan, I've seen a couple pianos that required removing the stretcher to access cheek block screws running down thru the top of the blocks into the keybed. Fenton ------------------------------ Fenton Murray, RPT Fenton ------------------------- ...

  • Posted in: Pianotech

    Entertaining mad scientist video :) So one could surmise that even a flat board, or one with seemingly zero bearing, is actually still under tension.

  • Posted in: Pianotech

    Jim - "misleading unto bogus" - can you describe how so? ------------------------------ David Skolnik [RPT] Hastings-on-Hudson NY 917-589-2625 ------------------------------