regulation problems in Aeolian era M and H 50"

[Richard Brekne]

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Dave.

Been reading back and forth your replies to posts coming in on this, and 
cant help but wonder about this gargantuan amount of air between where 
you say the key stops and the front rail punchings.  20 mm is like a 
huge amount.... even 10 mm away from the punchings is a ridiculously 
large amount.  I have a hard time understanding that any of this can be 
accounted for by the points suggested so far... not even in combination 
when it comes to it.

Assuming you have even 5-6 mm of key travel, a 20 mm gap at the bottom 
of this travel means there is over 25 mm of space between the bottom of 
the key and front punchings.  Or taking your lowest samples of 12 mm 
gaps... a near usual amount of key travel (10 mm) means about the 
same... 22 mm.

Key height would have to be well over 6-7 mm too high ... which you 
would easily be noticed by the bottoms showing way over the top of the 
key slip...which you havent noted so I can only assume thats not the 
case.  Conversely... if you key bottoms are at all below the top of the 
key slip... then key height can not be more then a small amount too 
high.... far to little to account for your stated problem.

Off hand something sounds broken... and rather big time.  That said, a 
couple basics to confirm for next time you check the piano.

--Just how much key travel are you getting.  (should be around 10 mm)
--Just how much distance is there between the bottom of the keys and the 
front rail punchings with the keys at rest. (should also be around 10 mm)
--Where are the bottoms of the keys height wise in relation to the top 
of the key slip. (should be somewhere around 3 mm below the top of the 
key slip... certainly no higher then that)
--Check whether or not the keys are binding... simply remove the action 
and see whether or not they can fall or be easily depressed a full 12 mm.


Unless something is broken  .. about the only thing I can think of that 
can account for such a large distance between the key bottoms and the 
front punchings with the keys at rest is a combination of somewhat high 
keys and nearly nothing for front punching thickness.  In which case 
this is at least to some degree a separate problem for why you are not 
getting any aftertouch with your stated 1 7/8 hammer blow. That, and the 
bobbling must be caused by some lack of key travel. 

What could be happening here is that the keys are  binding on something, 
like the mortise in the balance rail holes, and at some time some tooner 
tried to solve the problem of bobbling by removing most of the front 
punching thickness and in general mucking up the regulation.  But 20 mm 
at the bottom of key travel.... shheeeshh... thats hard to imagine.

 
Cheers
RicB




Piannaman@aol.com wrote:

>
> Ric, David,
>
> The more I think about it, the more I doubt that it's the jack stop 
> rail.  As Ric says, that would not account for the ridiculous amount 
> of dip, and would cause jack breakage.  
>
> The more I think about this--and it's been far too much in recent 
> days--the more I'm thinking that it's either capstan position as Jon 
> Page suggested, or a really poorly assembled piano, or both.
>
> There is not much damper pedal travel on this piano, and the dampers 
> don't lift high enough off the strings with use of pedal or with key 
> stroke.  I will check damper stop rail, but that still doesn't account 
> for the keydip.  
>
> Perhaps the balance rail was positioned too far back towards the 
> action when the piano was assembled...?  Quality control at that 
> factory in those days was not optimal, so nothing would surprise me 
> here!  Nor would it surprise me if the problem was something terribly 
> obvious.
>
> I'm gonna go play with my action model.
>
> Dave Stahl
>
> Original post:
>
> >>I've got some regulation problems on a 50 inch Mason upright from 
> the 70s.  I've worked on other Aeolian uprights of that vintage, and 
> some of them have the same problem.   
>
> The initial problem was that the keys weren't bottoming out on 
> punchings.  It seems that it's been that way since new(though they 
> bought it used).  There was a huge gap between the bottom of the key 
> and the punching when the key was depressed.  This led to hammers 
> blocking, bobbling, and a feel that could only be described as spongy.   
>
> At my last visit, I added punchings, and improved the feel somewhat, 
> but some of the bobbling is still there.  I also had to increase 
> letoff distance in some areas of the keyboard an unacceptable amount 
> to get it to work without hammers blocking against strings.
>
> I think that the main problem is that the key height is too great.  It 
> was somewhere around 70mm, though I forgot to write it down.  More 
> precise measurements are necessary, and they will be forthcoming after 
> my next visit there in January.  Blow distance is at 1 7/8(the only 
> thing in the piano that seems at spec...:-), but it doesn't seem to be 
> enough.
>
> I tried lowering the key height on a few sample keys by removing 
> balance rail punchings, but there was nowhere near enough aftertouch. 
>  Should I try increasing blow distance to 2 inches or more?  Any 
> ideas???  Haaalp??   
>
> Any input is welcome,
>
> Dave Stahl >>



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