CAUT

Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested

This caught my eye:  "I followed the Yamaha recommended sequence to putting the screws in"

 I don't think I remember hearing that there was a Yamaha recommended sequence. Mostly what I've heard is not to put in angled screws before the ones that go straight down. Generally I put the screws into the 4 corners first, and then put the rest in. Sometimes I've tightened them like lug nuts, basically jumping around as I tighten in an attempt to get even stress. I'm always wondering how much it really matters. 

Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested

This caught my eye:  "I followed the Yamaha recommended sequence to putting the screws in"

 I don't think I remember hearing that there was a Yamaha recommended sequence. Mostly what I've heard is not to put in angled screws before the ones that go straight down. Generally I put the screws into the 4 corners first, and then put the rest in. Sometimes I've tightened them like lug nuts, basically jumping around as I tighten in an attempt to get even stress. I'm always wondering how much it really matters. 

Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested

There is always a certain amount of inevitable twist on the keyframe and action frame.

I have found the best way to get consistent results is to install all the screws in the same order,

keeping in mind that angled screws will move the action rearward if installed early on. 

FWIW, it makes sense to me to always follow a routine:

Back corners,

Front corners,

Back row from outside toward center,

Front row from outside toward center. 

While it may not make a huge difference, it does ensure that all the frame members twist the

same way every time, thereby avoiding small differences when things are not done in the same 

sequence and minimizing any related duplication of effort.

This caught my eye:  "I followed the Yamaha recommended sequence to putting the screws in"

 I don't think I remember hearing that there was a Yamaha recommended sequence. Mostly what I've heard is not to put in angled screws before the ones that go straight down. Generally I put the screws into the 4 corners first, and then put the rest in. Sometimes I've tightened them like lug nuts, basically jumping around as I tighten in an attempt to get even stress. I'm always wondering how much it really matters. 

Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested

There is always a certain amount of inevitable twist on the keyframe and action frame.

I have found the best way to get consistent results is to install all the screws in the same order,

keeping in mind that angled screws will move the action rearward if installed early on. 

FWIW, it makes sense to me to always follow a routine:

Back corners,

Front corners,

Back row from outside toward center,

Front row from outside toward center. 

While it may not make a huge difference, it does ensure that all the frame members twist the

same way every time, thereby avoiding small differences when things are not done in the same 

sequence and minimizing any related duplication of effort.

This caught my eye:  "I followed the Yamaha recommended sequence to putting the screws in"

 I don't think I remember hearing that there was a Yamaha recommended sequence. Mostly what I've heard is not to put in angled screws before the ones that go straight down. Generally I put the screws into the 4 corners first, and then put the rest in. Sometimes I've tightened them like lug nuts, basically jumping around as I tighten in an attempt to get even stress. I'm always wondering how much it really matters. 

Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested

Thanks Jim and Dave - great description. This gets me thinking about another issue related to keyframes: what type of surface is the keyframe on when the screws are installed and tightened. In the shop I have workbench space, but in the field its either the LaRoy caddy, or the piano  bench, or the top of the piano. I'm imaging that uneven stresses on the keyframe could also have an effect. Perhaps just a drop cloth on top of the piano would be best so that the entire frame is well supported. So many details to worry about...

There is always a certain amount of inevitable twist on the keyframe and action frame.

I have found the best way to get consistent results is to install all the screws in the same order,

keeping in mind that angled screws will move the action rearward if installed early on. 

FWIW, it makes sense to me to always follow a routine:

Back corners,

Front corners,

Back row from outside toward center,

Front row from outside toward center. 

While it may not make a huge difference, it does ensure that all the frame members twist the

same way every time, thereby avoiding small differences when things are not done in the same 

sequence and minimizing any related duplication of effort.

This caught my eye:  "I followed the Yamaha recommended sequence to putting the screws in"

 I don't think I remember hearing that there was a Yamaha recommended sequence. Mostly what I've heard is not to put in angled screws before the ones that go straight down. Generally I put the screws into the 4 corners first, and then put the rest in. Sometimes I've tightened them like lug nuts, basically jumping around as I tighten in an attempt to get even stress. I'm always wondering how much it really matters. 

Wim  ... I had the top stack off so I could ease the keys. The screws in the action brackets where all tight as found. When I put the stack on I followed the Yamaha recommended sequence to putting the screws in . I have no idea about who serviced the piano before or why drop screws where all the way up as well as letoff buttons. I am returning tomorrow morning to take various measurements and possibly set some samples. In addition I have to install a hammer that was broken right at the tip of the shank glue joint. I will certainly take the measurements that Mr. Roeder suggested

Good points all esp. Kathy's regarding the glide bolts.  

I have "rescued" several technicians who have called me to find out why the action they were working on didn't work after R/R the action stack.  "It worked OK before I took it apart"!!  In those cases it was the angled screws holding the front of the stack up off of the key frame.  Like Jim's scenario above with the angled screws front AND back simply holding the stack in place or even a clamp might help to get the stack "seated" so that the threads of the screws are not holding it above the action frame.  It's actually really, really solid when properly bedded.  

Also, I can't tell you how many action stacks I have simply screwed down that were loose and conquered a whole world of issues previously present.  Things like lost motion, hammer tails catching on back checks and even sluggish repetition springs (they weren't being compressed enough) not to mention all the clicky-ticky noises as a result.  

Mike 

One other thought BTW.  How about checking the action spread?  Could it have been altered at some point.  Might explain a bunch, particularly with regard to the let off buttons.

Mike

Good points all esp. Kathy's regarding the glide bolts.  

I have "rescued" several technicians who have called me to find out why the action they were working on didn't work after R/R the action stack.  "It worked OK before I took it apart"!!  In those cases it was the angled screws holding the front of the stack up off of the key frame.  Like Jim's scenario above with the angled screws front AND back simply holding the stack in place or even a clamp might help to get the stack "seated" so that the threads of the screws are not holding it above the action frame.  It's actually really, really solid when properly bedded.  

Also, I can't tell you how many action stacks I have simply screwed down that were loose and conquered a whole world of issues previously present.  Things like lost motion, hammer tails catching on back checks and even sluggish repetition springs (they weren't being compressed enough) not to mention all the clicky-ticky noises as a result.  

Mike 

Michael   ... what should the action spread be for this action ? I have replaced several sets of action brackets on Young Chang pianos including other pianos that had expanding brackets. I would have to look at the instructions I have that came with the replacements. 

One other thought BTW.  How about checking the action spread?  Could it have been altered at some point.  Might explain a bunch, particularly with regard to the let off buttons.

Mike

Good points all esp. Kathy's regarding the glide bolts.  

I have "rescued" several technicians who have called me to find out why the action they were working on didn't work after R/R the action stack.  "It worked OK before I took it apart"!!  In those cases it was the angled screws holding the front of the stack up off of the key frame.  Like Jim's scenario above with the angled screws front AND back simply holding the stack in place or even a clamp might help to get the stack "seated" so that the threads of the screws are not holding it above the action frame.  It's actually really, really solid when properly bedded.  

Also, I can't tell you how many action stacks I have simply screwed down that were loose and conquered a whole world of issues previously present.  Things like lost motion, hammer tails catching on back checks and even sluggish repetition springs (they weren't being compressed enough) not to mention all the clicky-ticky noises as a result.  

Mike