[pianotech] Lyre Damage

[Ron Nossaman]

William Truitt wrote:
> Let me re-ask my question again, Ron.  To what other possible causal agents
> could you possibly attribute the upward distortion of the keybed that we so
> often see? 

I certainly can't blame rocking it on the lyre in the pianos 
I've seen in this condition that haven't been moved in many 
years. I'd be more likely to blame humidity shifts. And is it 
an upward distortion of the key bed, or a distortion in the 
action that's to blame? And how have you determined either?


> What would qualify as "reasonable evidence" of a direct causal relationship
> between setting the piano down on the lyre and keybed warpage?  Both Al and
> I have given instances of observation soon enough after such a move that any
> other cause is unlikely, and the lyre is the most obvious suspect. 

And David indicated, as have I, that a whole lot of pianos get 
moved using the lyre, that show no such problems. Two reported 
suspected instances against a whole lot more instances where 
no such problem occurs doesn't meet my criteria for reasonable 
evidence.



>Neither
> of us are trying to make the leap of saying that all instances of warped
> keybeds are caused by setting the piano on the lyre, only that we have a
> particular instance where doing so is the only reasonable suspect.  

Reasonable suspect? Again, did you determine the key bed was 
deformed, or did you assume it because the end action glides 
were floating?


>As to
> how many instances are caused by setting the piano on the lyre, you and I
> share essentially the same incomplete knowledge, regardless of our position.
> We rely on anecdotal information and hopefully good logic, because we don't
> have much else to go on.

Which is why I said there's no reasonable evidence saying that 
rocking on the lyre deforms key beds, making the end glide 
bolts float. The number of observances against it are far 
higher than the number in favor. I couldn't care less who's 
right here, but I am interested in *what's* right, and I still 
see no reasonable evidence of lyre moves damaging key beds.


> David, I don't doubt that a great many pianos are moved by setting the piano
> on the lyre, and no harm comes of it.  Lots of movers do it that way with no
> ill effects (at least most of the time).   A Steinway is a substantially
> built piano with a thick keybed.  But there are plenty of Crappendorfer
> pianos out there where the keybed is as insubstantial as the rest of the
> piano, and as cheaply made.  And less tolerant of insult than the better
> made instruments.  

Like that Hamburg C you used as an example of damage incurred 
by, you presume, rocking it on the lyre, which you also presume?


> As for the side stresses on the treble leg, fair enough.  Perhaps one could
> even say it is a question of choose your poison, but you have to choose one
> because you have to move the piano.  One way to lessen that stress is to
> make sure that you spin the caster wheel on that leg so that the wheel is
> facing outward and away from the rim.  Otherwise, at a certain point in
> lowering the piano down at the bass end, the wheel will spin on its own to
> achieve that position, suddenly and with a little jolt, adding more stress
> than needs to be there.

I know all that. I wasn't looking for instructions, just 
making a comparative observation.


> For me, it is not hard to draw the following conclusion:  IF it is true that
> some instances of keybed warpage exist due to setting the piano on the lyre,
> whether caused by poor and rough technique, the insubstantiality of the
> keybed, or both; AND IF it is true that simple, quick, easy, and safe
> methods exist that remove the need to set the piano on the lyre when moving
> and risk such damage, THEN wouldn't it be true that said methods would be a
> better and safer choice for moving a piano? (Logic 101 - if A is true, and B
> is true, it follows that C must be true)

If you like.


> If one were so inclined, it probably would not be too difficult to set up a
> long straight edge with a dial guage or digital caliper to take measurements
> of deflection, both temporary or permanent, on a number of pianos, just to
> see how much the keybed actually changes when doing a move.

If one was interested in learning something, one should be so 
inclined as to attempt to find out. I just now did that, on a 
NY D, with a straightedge and punchings. A dial indicator, 
which I have handy, would take longer to set up, and wouldn't 
tell me anything more than this did, just to more decimal 
points. Key bed is concave by 0.06" in the center. Jack up one 
side, and float the piano on the lyre with a scrap of 2x4. Key 
bed is now 0.04" concave. The full weight of the piano on the 
lyre deflected it 0.02", or thereabouts. Removing the block, 
it went back where it was, nearly as I could tell. The end 
glide bolts didn't knock when it was up on the lyre.

Is this proof of anything? No, not really. But it's an 
indication to me, along with the many years of similar 
indication, that rocking on the lyre doesn't typically 
endanger the key bed.

For most of the time I've been in this business, I've set 
pianos up and down without the lyre, concerned with breaking 
the lyre or at least loosening the glue joints. So I'm not 
questioning the point because I'm defending my own 
"questionable" practice. I'm questioning it because, other 
than the structural risk to the lyre, I don't think it's 
likely enough to screw up key beds or action regulation, to 
use that as an argument against the practice.

Ron N