I would like to know if, for the purpose of restoring the geometry of the bridge (the upright under the walnut, etc...), it is good practice to first proceed with applying veneers under its hitch pins and, if that is not sufficient, to bore out the hitch pin hole to allow for easier repositioning.
Furthermore, what should be done in the case where the hitch pins and the bridge are okay but it is the upright that is crooked (perhaps because it has worked poorly...)? In the case of the tail, I know it is common practice to strike the upright with light taps to straighten it... in the vertical position it is not so obvious; proceeding this way on the vertical also seems a bit risky to me...
Having confirmation to proceed in the right way from Maestro Ferrarelli is always a welcome thing.
I am currently repairing an upright piano whose action presents a lot of friction, and I was wondering if there is an empirical method to detect the correct friction also for the key lever and the center pin, avoiding buying the relative gauge (which is rather expensive). As far as the hammer butt goes, I know that it should be allowed to fall and should not oscillate more than 5 or 6 times around its center pin, but such a method is unknown to me for the key lever and center pin as well...
The forcole can be tested with your own screw. Place the screw in the hole and let the forcola fall under its own weight. It must fall slowly and uniformly. Slowly means "the right amount of friction." Uniformly means that the hole has been properly reamed and the cashmere seat has perfectly parallel walls (in fact, non-conical reamers must be used to enlarge the hole. I remind you that the pins must always be replaced with larger sizes to ensure that the pin seat in the wooden part is firm). The pusher must fall, simply moving under its own weight (after being released from the spring).
I understand, everything is clear. However, one could think about replacing the boring of the holes with a cashmere stretching (partially pulling out the pin and heating it) or by using Protek? I often hear conflicting opinions about this around here
Conflicting opinions ... in short; it is experience that has shown that lubricating the pin only makes things worse because over time it becomes gummy and jams, more than before. And having to remedy this kind of intervention is never pleasant. Heating the pin, on the other hand, turns out to be only a temporary fix.
I agree with Giovanni. My opinion: NEVER lubricants... not even Protek. Heating the pin temporarily solves it, but.... it expands the cashmere.... but it also expands the seat where the pin is tightened in the wood. When cooling, the pin shrinks, while the hole in the wood remains expanded. So, a double problem. Otherwise, why would the pins be increased, at least by one size? Naturally "conflicting opinions".... this is my opinion and... also that of our friend giovannig, it seems to me! Ciao
I agree with Giovanni. My opinion: NEVER lubricants... not even Protek. Heating the pin momentarily solves it, but.... it expands the cashmere.... but it also expands the seat where the pin is tightened in the wood. When cooling, the pin shrinks, while the hole in the wood remains expanded. So, a double problem. Otherwise, why would they increase the size of the pins, by at least one size? Naturally "conflicting opinions".... this is my opinion and... also that of our friend giovannig, it seems to me! Bye
Of course Paolo, I think the same way. Best regards.
Why is it that when the motor field weakening combinators on the E 444 locomotive lock, one cannot start the train using only the rheostat cutout lever, and even with the help of the accelerated cutout lever, one cannot achieve the initial surge... etc.. etc.. Oops, I think I've got the wrong forum... look, this is not a site for railway enthusiasts... just as it is not a site for piano technicians... so either support your opinions with videos or drawings, or just have a conversation among yourselves.... showing off your knowledge.... for what purpose? I think the purpose of a non-dedicated forum.. I repeat, NOT DEDICATED, is that everyone knows what you are talking about and then videos are attached to support the discussion. Regards
I believe everything is quite clear. Each of us answers the questions that are asked, giving our own suggestions and opinions. As I have stated in the video tutorials, this site of ours and especially the forum does not intend to replace the Technician and/or the Teacher. There is no claim even to establish a "do-it-yourself school." It is possible to suggest how to carry out small repairs and/or interventions proportionate to the level of knowledge of the subscriber. For example, this intervention on the pins is an expert intervention, and a video could even encourage performing incorrect operations. Instead, we have repeatedly emphasized that our efforts aim to help pianists better understand which interventions and adjustments are necessary on their own instrument, in order to then better communicate with the Technician and/or the Teacher.
