[CAUT] upright action

[Mark Cramer]

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Hi Les,

just a couple thoughts,

1.) Squareness: Hold a straightedge against the "tails" of the hammers to
verify the hammers will hit strings squarely. Presuming the originals
weren't angled slightly for passing clearance, all tails should be square to
your straight-edge with no gaps.

The hammers need to either be at rest or against the strings (which are
presently elsewehere, as you've noted) for this to be accurate. It's also
helpful to rest a peice of aluminum angle between the shanks and the rest
cloth.

2.) Damper Clearance: You mentioned the new hammers were smaller... all the
same, make sure they will clear the damper felts.

3.) Strike Line & Hammer-to-String Alignment : Strike line isn't so critical
"tonally" in the bass, however, bear in mind as you raise/lower hammers
vertically, the strings deviate diagonally. 

IOW, the more you deviate (higher/lower) from the original strike line, the
more lateral spacing you will have to do. Especially critical if you're
dealing with an old brass-flange action. 

(I know we're just talking bass hammers, but for the record I always try
install #88 at the piano to establish strike and preserve the original
action position. You can always adjust the action later, but this puts the
delicate bass damper-to-string alignment at risk)  
   
I think your action will work out fine Les. 

Once the hammers are on, check traveling again (easier on the bench than at
the piano).

At the piano, slide the angle aluminum rest back between shanks and
rest-felt, and check the squarness of tails again with your straight-edge.
Yes, you can sight between hammers for "parralel" too, but as Fred suggests,
"ignore" hammer-to-string spacing at this point.

Burn-in any shanks until hammer  tails are square to the straight-edge. 

Now, wedge the rest-rail as close to the strings as possible. Your hammers
should be very square to the plane of the strings.

Now you can evaluate spacing, and adjust as Fred describes.

Once spacing appears correct, sound each bi-chord note, muting one string at
a time. Both should sound the same. That's the reward for all your careful
work! 

"Travel, twist and space, always in that order" (my good friend and mentor,
Ted Sambell, RPT)

best regards, 
Mark Cramer,
Brandon University


     





>  -----Original Message-----
> From: 	caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] 
> Sent:	Thursday, November 24, 2005 1:41 PM
> To:	caut@ptg.org
> Subject:	[CAUT] upright action
> 
> A few questions, one of which may rouse a bit of flame, but I'm getting
> desperate.......  I got stuck with rebuilding a 100 year old S&C upright,
> and don't actually have a shop.....  The stringing and key-work has been
> sent out, but I'm left with the action.
> 
> 1. Is there any reason NOT to hang bass hammers before I have the piano
> back from restringing?  I have two samples already hung. Treble hammers
> look pretty decent.
> 
> 2. If, after attempting to align strings to hammers, a few are still not
> "perfect" is it sort of legit to use heated shank bending pliars to align?
> I don't think anything would have to move more than an eighth of an inch.
> 
> 3. Is the old gummy paper tape, for traveling, still available?
> 
> 
> Thanks
> les bartlett << File: ATT00011.txt >> 

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