regulation problems in Aeolian era M and H 50"

Piannaman@aol.com Piannaman@aol.com
Mon, 20 Dec 2004 11:17:01 EST


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In a message dated 12/20/04 12:13:06 AM Pacific Standard Time, 
Richard.Brekne@grieg.uib.no writes:


> I would submit that if the jack rail was causing key travel to stop as 
> 12 - 20 mm from the front rail cushions, then you'd have one whale of a 
> lot of broken jacks. The first time you play a bit hard you the jack 
> centers would be so stressed that jacks would easily break there.  I 
> mentioned something similiar with the damper wires earlier on...  
> Anything like this being responsible for stopping key travel in midair 
> as it were would have to be able to handle the stress of hard play as 
> well... or parts will break.
> 
> Keith is right about one thing tho.... whatever the problem is it will 
> be painfully obvious when first noticed.

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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