regulation problems in Aeolian era M and H 50"

[Piannaman@aol.com]

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In a message dated 12/18/04 1:17:08 PM Pacific Standard Time, 
Richard.Brekne@grieg.uib.no writes:


> Piannaman@aol.com wrote:
> 
> > Salutations,
> >
> > 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.
> 
> 
> I am not sure I understand here.... what is inhibiting the keys from 
> bottoming out ?  Is there a stop rail at the back of the keys ? Is there 
> something about the regulation of the action itself that meets a stop 
> rail before the keys bottom out ?
> 
> You should be able to get a 9-11 mm dip range with no problems whatsover 
> (outside of the obvious general regulation consequences of too deep or 
> too shallow a key dip).Bottoming out should be no problem in this range.
> 
> If key height is way too high, then the bottoms of the keys will show 
> over the keyslip rail yes.... I have a hard time seeing that anyone 
> would set them so high as to cause them to not bottom out... but who knows.
> 
> Off the top of my head, from your discription so far it sounds like 
> perhaps the dampers are hitting the stop rail before the key gets a 
> chance to reach bottom. That would explain the spongeyness, and could 
> account for bobbling. But if you force the key down you should be able 
> to stress the damper wires enough to hit bottom... so I am just 
> guessing.  Something, however, must be stoping the keys from hitting 
> bottom and you need to find out what that something is.
> 
> Check all your regulation points first,  get all of those within 
> acceptable tolererances before anything else.
> 
> Cheers
> RicB
> 
> 
Ric,

I don't know if it's even posssible.  I'm convinced the geometry is totally 
screwed up, and I need to figure out why and where.

The key dip before I changed the punchings and added cardboard punchings was 
anywhere between 12mm and 20mm depending on how hard you pushed.  In other 
words, it was not governed by the front rail punchings, rather by how hard you 
pushed and forced the capstan to the wippen, jack to hammer butt, hammer to 
string.  Even then, the keys were not touching the punching.  I think that this 
piano was built in the dying days of Aeolian, and that they forgot to check 
things, like keydip.  It is weird.  And the thing has been tuned regularly since 
new, judging by all of the pencil marks on the plate.

Thanks for the input,

Dave


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