[CAUT] a simple question

[Ron Overs]

Hello Paul,

I've found that you can work quite quickly when a suitable clearance 
is chosen for the hammer bore hole to shank diameter. It is also 
important to have the Titebond thickened so it sets up quickly.

I generally like about 4 to 5 thou hole clearance between the hammer 
core and the shank. I also like to roll the shanks prior to drilling 
the hammers, to make sure that they are all pretty much the same 
diameter. Even with new shanks there will be quite a deal of 
variation in the shank diameters. Knurling them will significantly 
reduce this variation. I also have a separate container to hold the 
Titebond we use for hammer hanging. I leave this with the lid off, 
stirring it regularly until it reaches the viscosity I want for 
hammer hanging. The combination of even shank diameters, appropriate 
hammer drilling diameter and nice thick Titebond allows me to hang 
one hammer, then check the one I've previously hung, to finalise its 
burning angle, head angle, strike point and tail position. I believe 
the alignment of the tails is just as important as the alignment of 
the hammers to the strike line (or curve). If the tails are all over 
the place it will result in significant hammer to hammer mass 
variation once the tails are shaped. I like the tails sitting in a 
nice line so that the tailing jig/disc sander takes the same amount 
off each tail. This makes the final job of balancing the hammer-set a 
much quicker operation (about 1.5 hours for me at this time).

An image of our tailing work and the spreadsheet that we use can be found at;
http://members.optusnet.com.au/kristieovers/hmrtail.jpg

An image of a balanced hammer set at the bass/treble cross can be found at;
http://members.optusnet.com.au/kristieovers/stmarysd9.jpg

The hammer in the foreground (D#19) was lightened 0.1 gram with the 
2.5 mm hole in the core wood, while the hammer F21 has two lead wires 
inserted (1.7 mm diameter) which increased the hammer weight by 0.4 
gram. Notice also that we've cut the hammer cove of the bass hammers 
deeper to reduce the mass difference between the bass and treble 
section hammers. This compensates somewhat for the longer (and 
therefore heavier) bass section hammer tails. These hammers were hung 
on a Hamburg D we rebuilt late last year. It turned out to be one of 
the most unsatisfactory rebuilding outcomes we have done in perhaps 
the last decade. The piano was fine, but the client . . .

For those who haven't seen the piano, other links to images can be found at;

http://members.optusnet.com.au/kristieovers/st.mary's1.jpg

http://members.optusnet.com.au/kristieovers/st.mary's2.jpg

http://members.optusnet.com.au/kristieovers/st.mary's3.jpg

http://members.optusnet.com.au/kristieovers/st.mary's4.jpg

While I, and some of my colleagues here in Sydney including David 
Kinney and Geoffrey Pollard - the house technician from the Sydney 
Conservatorium of Music, were most satisfied with the end result, the 
head piano teacher of the college decided that he didn't believe the 
piano 'sounded like a genuine Steinway' anymore. He also called in 
alleged experts who were not only by his account leading pianists, 
but were also Steinway owners. They apparently agreed with him. I 
told him that he really should give the piano a chance for the 
hammers to settle in. But like so many 'smart Alecs' who think they 
know everything, but have no experience with a fine set of cold 
pressed hammers, which admittedly don't knock your head off with 
their brightness when new, he continued to bully me over the matter. 
He even called in the local Steinway representative who pronounced 
that the hammers weren't genuine Steinway (of course, they were 
custom made by Abel - so what!), and furthermore he thought that they 
might have been a bit lighter than the standard hammers. Fortunately, 
having balanced the new hammer set, and having measured the original 
hammers as a reference, I was able to email a pdf file of the hammer 
weight spreadsheet to the college and the Steinway agent, which made 
a mockery of the claims of the Steinway agent. Its now 20 weeks since 
I did the final installation tuning and check over. Last week David 
Kinney tuned the piano again for the college. David told me that the 
piano has developed into a quite remarkable instrument. Still not one 
positive word from the teacher (I won't hold my breath waiting). 
Apparently David spent some time with him demonstrating the 
characteristics of the piano. I wonder if he was listening, or 
whether his eyes were glazed over as they seemed to be whenever I was 
speaking with him. You can tell how delighted I am about this. It 
upsets me to throw pearls before swine, especially when we are unable 
to negotiate a fair return for our work because we are looked down 
upon, as some sort of leper.

Ron O.

>How long, when hanging hammers using titebond do you let it sit 
>before going to the next section?  I'm going with 2 hours.  I like 
>letting them sit over-night, but I only have one Sprulock jig and 
>I'm trying to get this done quick. I'm thinking of getting a second 
>jig to double the time (half the time)  What say you?
>
>BTW; Whos going to Oberlin next week?  Let's hook up for a refreshment!
>
>Thanks
>
>Paul


-- 
OVERS PIANOS - SYDNEY
    Grand Piano Manufacturers
_______________________

Web http://overspianos.com.au
mailto:ron at overspianos.com.au
_______________________
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