Leuke demonstratie, die "slingertest". Wat je daarmee in wezen laat zien is het verschil tussen traagheid (=massa) en traagheidsmoment. Toets, onderhamer en hamer zijn roterende voorwerpen, als je wil dat dat systeem snel reageert is niet zozeer de massa of traagheid van belang maar het traagheidsmoment. Dan is het inderdaad het beste om de loodjes die je aanbrengt zo dicht mogelijk bij het draaipunt te plaatsen.
Haha idd Ze pasten in deze context echt te goed! Sterker nog ik heb twee copyright claims lopen hiervoor tegen CDBaby ;) Ik neem aan dat jij een mailtje gaat krijgen hierover?
Haha, fijn om te weten dat het werkt! Volgens mij zie ik die fracties van centen op een gegeven moment verschijnen op mijn overzicht. #momoneymoproblems @@CoenvanDongen
De slingertest met een horizontale as is niet optimaal, omdat de drijvende kracht afhangt van het zwaartepunt van de toets en de afstand daarvan tot het draaipunt. Beter is het om de slingeras verticaal te doen en de drijvende kracht dmv een torsieveer te genereren. Dan zijn de metingen vergelijkbaar. Verder is het zo, dat een zeker lood-gewicht aan het eind van de toets hetzelfde doet voor het neergewicht als het dubbele gewicht op de halve arm. MAAR: het massatraagheidsmoment gaat volgens arm*arm*massa. Derhalve is het massatraagheidsmoment van het lichte gewicht aan de tip van de toets tweemaal zo groot. Dus is het gunstiger om veel lood nabij het kantelpunt aan te brengen. Dit is helaas wel duurder. Ook kan men aan de achterkant van de toets hout verwijderen om de benodigde hoeveelheid lood te verminderen. De vraag is of de snelheidswinst die op deze manier wordt bereikt noodzakelijk is voor de speelaard. Basnoten zijn zelden prestissimo. Omdat de hoogste noten weinig lood benodigen en weinig massatraagheid hebben, kan het voor de speelaard gunstig zijn om het lood verder naar de tip van de toets aan te brengen. Als het massa-traagheidsmoment dan nog niet voldoende is, kunnen gelijke hoeveelheden lood voor en achter het kantelpunt dit verder verhogen, zonder dat dit het statische speelgewicht vergroot.
@@CoenvanDongen Leads near blance pin are better for fast repetition. And if you make the hammers and the key ends lighter, you will need less leads. Great footage, thanks.
Hi Chris, I kind of understand your comment. And I'm sorry if you feel this way. But I don't think I copied your experiment. I've seen David Stanwood and the PTD community doing this example of swinging keys for decades. I understand by the timing of this video you will think otherwise. Also you and me have been doing it on pretty different ways and we are taking different conclusions. Your way of "fixing" the inertia feels to me almost the oppositie of how I'm trying to take care of it. I hope I did not offended you in any way with my video. I like your videos and respect you as a technician.
So sue him for copy-right infringement. No one knows who invented calculus but if Isaac Newton and Gottfried Wilhelm Leibniz owed one another an apology, it never happened.
@@CoenvanDongen No worries Coen. I like your channel too. I can follow along pretty well even though its in another language. Don't worry about a lawsuit as suggested by another user as we are only talking about etiquette. If i ever see a good idea on your channel i will gladly give you credit for it.
Great videos! I think you may realize that standwood doesn’t yield to any magical action. There are pianos out there sometimes Steinway sometimes not, right from the factory with absolutely heavenly action that every famous pianist in the world is just in love with. And those action don’t draw a nice graph in excel for down and up weight. Because pianists don’t feel the difference between 48g or 52g. There are actions at 40g which all pianists will say is heavy, and actions at 60g which all agree feels light. The uniformity from note to note in terms of grams is just not the solution. Although it doesn’t hurt to please the excel graph, it’s just not the solution and the answer is not there. Sorry to say. Your experiment with where to place the weights has failed because you even mentioned you arrived at no conclusion. Therefore you place somewhere in the middle o in hopes that the middle is the good place. That is not a conclusion nor is it scientific. You should explore further the difference between small weight in the end versus large weight in the center. I fear you will not find much difference in reality between the 2 cases but it’s worth exploring with extra effort. The true soul of any action is fundamental and rather basic. For every x mm the key moves down, how many mm does the hammer move up. If this ratio is to the pianist taste, they willl find heavenly action regardless of touch weight up or down. Of course if there is too much friction, it’s all garbage anyway.
You don't need to say sorry to say. I completely agree with you. Downweight does not tell much about the playability. And factorys in general do a pretty good job making good playing instruments. And yes a good balance between the hammerweight and Ratio has the biggest share in a good playing instrument. The point of the experiment was that it is impossible to make two matching grand pianos with a different lead pattern. And also probably impossible to say if one is better than the other. I think there will be a matter of taste involved with this. The experiment did point out that there is a difference between lead in the front and lead in the back. So when calibrating the keys I think the placing of the lead should be as regularly as possible. Putting the lead regularly in the front or in the back would be fine also. As long as it is regularly. The lead pattern method I show is imo a great way to achieve this. I've also seen other good ways. So Yes, placing of the lead, and balance weight is just a little piece of the bigger puzzle. But I think it is great to take every little piece of the puzzle (at least) in consideration when balancing an action.
@ perhaps it’s best to decide where the leads to go, by weighing the entire key? And by making sure the keys from a0 to c8 reduce in over all weight evenly and in a linear way? Have you graphed the key weights after installing your leads? The entire key, on a scale. As a whole, with the back check and capstan etc. I’m just thinking. I don’t know. I don’t have the answer to the leads :) Pianos are very annoying. Nothing too much is good. Nothing too little is good. Always some golden middle zone where things are nice. So max inertia is probably not good. Minimal inertia is not good. The question is simple. Lots of weight near the center or less weight near the end. I would have done the experiment in a more extreme way. Put a huge amount of weight extremely close to the center. I can imagine that with this scenario, any acceleration such as pressing down on the key from the up resting position would have minimal resistance to change. Also the change of direction as the key returns up would be quicker. But the felt under the key in the center will be much more compressed, because the key is so heavy as a whole. And perhaps this compressed felt would give a lazy feeling to the key.
Leuke demonstratie, die "slingertest".
Wat je daarmee in wezen laat zien is het verschil tussen traagheid (=massa) en traagheidsmoment. Toets, onderhamer en hamer zijn roterende voorwerpen, als je wil dat dat systeem snel reageert is niet zozeer de massa of traagheid van belang maar het traagheidsmoment. Dan is het inderdaad het beste om de loodjes die je aanbrengt zo dicht mogelijk bij het draaipunt te plaatsen.
Briljant Coen. Daadwerkelijk tijd nemen om bekende vraagstukken te toetsen.
Great video this technique is amazing
Prima presentatie, proficiat Coen.
Great video. Thanks!
Fantastic
Next level deze video! Goed gedaan zeg. Thanks dat ik auditief ook weer even mag meepingelen ;)
Haha idd Ze pasten in deze context echt te goed! Sterker nog ik heb twee copyright claims lopen hiervoor tegen CDBaby ;) Ik neem aan dat jij een mailtje gaat krijgen hierover?
Haha, fijn om te weten dat het werkt! Volgens mij zie ik die fracties van centen op een gegeven moment verschijnen op mijn overzicht. #momoneymoproblems @@CoenvanDongen
Heerlijk om naar te kijken Coen, prachtig vakwerk!
🔥🔥
Very very good !
De slingertest met een horizontale as is niet optimaal, omdat de drijvende kracht afhangt van het zwaartepunt van de toets en de afstand daarvan tot het draaipunt.
Beter is het om de slingeras verticaal te doen en de drijvende kracht dmv een torsieveer te genereren. Dan zijn de metingen vergelijkbaar.
Verder is het zo, dat een zeker lood-gewicht aan het eind van de toets hetzelfde doet voor het neergewicht als het dubbele gewicht op de halve arm. MAAR: het massatraagheidsmoment gaat volgens arm*arm*massa. Derhalve is het massatraagheidsmoment van het lichte gewicht aan de tip van de toets tweemaal zo groot. Dus is het gunstiger om veel lood nabij het kantelpunt aan te brengen. Dit is helaas wel duurder. Ook kan men aan de achterkant van de toets hout verwijderen om de benodigde hoeveelheid lood te verminderen. De vraag is of de snelheidswinst die op deze manier wordt bereikt noodzakelijk is voor de speelaard. Basnoten zijn zelden prestissimo.
Omdat de hoogste noten weinig lood benodigen en weinig massatraagheid hebben, kan het voor de speelaard gunstig zijn om het lood verder naar de tip van de toets aan te brengen.
Als het massa-traagheidsmoment dan nog niet voldoende is, kunnen gelijke hoeveelheden lood voor en achter het kantelpunt dit verder verhogen, zonder dat dit het statische speelgewicht vergroot.
Bedankt voor de toevoeging!
@@CoenvanDongenDank voor de interessante en instructieve videos!
@@CoenvanDongen Leads near blance pin are better for fast repetition. And if you make the hammers and the key ends lighter, you will need less leads. Great footage, thanks.
It's common decency that when you copy someone else's experiments and ideas you give them acknowledgement.
Hi Chris, I kind of understand your comment. And I'm sorry if you feel this way. But I don't think I copied your experiment. I've seen David Stanwood and the PTD community doing this example of swinging keys for decades. I understand by the timing of this video you will think otherwise. Also you and me have been doing it on pretty different ways and we are taking different conclusions. Your way of "fixing" the inertia feels to me almost the oppositie of how I'm trying to take care of it. I hope I did not offended you in any way with my video. I like your videos and respect you as a technician.
So sue him for copy-right infringement. No one knows who invented calculus but if Isaac Newton and Gottfried Wilhelm Leibniz owed one another an apology, it never happened.
@@CoenvanDongen No worries Coen. I like your channel too. I can follow along pretty well even though its in another language. Don't worry about a lawsuit as suggested by another user as we are only talking about etiquette. If i ever see a good idea on your channel i will gladly give you credit for it.
Great videos! I think you may realize that standwood doesn’t yield to any magical action. There are pianos out there sometimes Steinway sometimes not, right from the factory with absolutely heavenly action that every famous pianist in the world is just in love with. And those action don’t draw a nice graph in excel for down and up weight.
Because pianists don’t feel the difference between 48g or 52g.
There are actions at 40g which all pianists will say is heavy, and actions at 60g which all agree feels light.
The uniformity from note to note in terms of grams is just not the solution. Although it doesn’t hurt to please the excel graph, it’s just not the solution and the answer is not there. Sorry to say.
Your experiment with where to place the weights has failed because you even mentioned you arrived at no conclusion. Therefore you place somewhere in the middle o in hopes that the middle is the good place.
That is not a conclusion nor is it scientific. You should explore further the difference between small weight in the end versus large weight in the center.
I fear you will not find much difference in reality between the 2 cases but it’s worth exploring with extra effort.
The true soul of any action is fundamental and rather basic.
For every x mm the key moves down, how many mm does the hammer move up. If this ratio is to the pianist taste, they willl find heavenly action regardless of touch weight up or down.
Of course if there is too much friction, it’s all garbage anyway.
You don't need to say sorry to say. I completely agree with you. Downweight does not tell much about the playability. And factorys in general do a pretty good job making good playing instruments. And yes a good balance between the hammerweight and Ratio has the biggest share in a good playing instrument.
The point of the experiment was that it is impossible to make two matching grand pianos with a different lead pattern. And also probably impossible to say if one is better than the other. I think there will be a matter of taste involved with this. The experiment did point out that there is a difference between lead in the front and lead in the back. So when calibrating the keys I think the placing of the lead should be as regularly as possible. Putting the lead regularly in the front or in the back would be fine also. As long as it is regularly. The lead pattern method I show is imo a great way to achieve this. I've also seen other good ways.
So Yes, placing of the lead, and balance weight is just a little piece of the bigger puzzle. But I think it is great to take every little piece of the puzzle (at least) in consideration when balancing an action.
@ perhaps it’s best to decide where the leads to go, by weighing the entire key? And by making sure the keys from a0 to c8 reduce in over all weight evenly and in a linear way?
Have you graphed the key weights after installing your leads? The entire key, on a scale. As a whole, with the back check and capstan etc.
I’m just thinking. I don’t know. I don’t have the answer to the leads :)
Pianos are very annoying. Nothing too much is good. Nothing too little is good. Always some golden middle zone where things are nice. So max inertia is probably not good. Minimal inertia is not good.
The question is simple. Lots of weight near the center or less weight near the end.
I would have done the experiment in a more extreme way. Put a huge amount of weight extremely close to the center. I can imagine that with this scenario, any acceleration such as pressing down on the key from the up resting position would have minimal resistance to change. Also the change of direction as the key returns up would be quicker.
But the felt under the key in the center will be much more compressed, because the key is so heavy as a whole. And perhaps this compressed felt would give a lazy feeling to the key.