Steinway "pinning" dilemma

[Don Mannino]

Hey Fred (and list),

I sort of figured you were putting more friction there in compensation
for conditions.  They should not loosen up as much as you said, though -
an average of .5 gram resistance drop in hammer flanges after 20,000
keystrokes is what I found when testing the process.  If the cloth isn't
very good that could make it worse, or if the broaches are too rough.

On the next repinning job you do on parts that are not too old, try
using only a 2 foot long stretch of music wire to burnish only.  Just
sharpen an end, then drag each part over the long wire.  If you are not
having to change the pin size up more than .001, then this burnishing
can be enough to create a firm and stable center with low friction (2 -
4 grams), even under heavy use.

The rough broaches you received were not made correctly - they sound
like the ones APSCO was selling, which were wrong and did not follow my
design.  You should not continue to use them - they should be trashed.

Schaff is making the sets with 8 broaches now, the smallest is .048 and
the larges .055.  These have been available for a couple of years now.
Be sure to run the broach onto the part all the way to the handle, so
that the rough area simply scuffs by the bushing as you run it on and
off.

I agree, the handles don't need to be as big as Schaff makes them, but I
sort of like the shape of them.

Don

> -----Original Message-----
> From: Fred Sturm [mailto:fssturm@unm.edu] 
> Sent: Friday, October 03, 2003 6:40 AM
> To: College and University Technicians
> Subject: RE: Steinway "pinning" dilemma
> 
> 
> Hi Don,
> 	I agree that for most purposes, 8 grams of friction in 
> a shank would be 
> excessive. I should have qualified the number:
> 1) Only on high use grands
> 2) with heavy-ish hammers
> 3) bass to tenor area
> 4) when  done during high end of humidity cycle
> 5) in conjunction with application of Protek
> 6) with a cross check of minimum three swings
> 	I have found a fairly rapid drop in friction after 
> re-pinning, somewhat 
> similar to drop in torque when stringing, where after two to 
> three months 
> (granted, of heavy use, and possibly drop in humidity), 
> friction will drop 
> by at least a couple grams, and number of swings will 
> increase from three 
> to five, from four to seven, or so. In a sense, what I am doing is 
> "floating" frictional parameters - making it too tight to 
> begin with so it 
> will be right longer. And removing as little felt as possible 
> to preserve 
> the bushings as long as possible. I typically use 3 to 5 
> grams for home or 
> low use. And maybe my dry climate and low air pollution has a 
> big effect on 
> efficacy of these parameters.
> 	I do use a commonly available set of tools known as 
> "Mannino broaches" 
> (hmmm, maybe some relative of yours, Don <g>), and rough up 
> the felt as 
> little as possible, in conjunction with solid burnishing. 
> BTW, I have found 
> those broaches can vary quite a bit. I bought two sets over 
> time, one for 
> home, one for school, and the first set was great. The second 
> had extreme 
> roughness in the cuttin area - real deep spirals. Not hard to 
> get around. I 
> just made my own rough spots a little down the wire, and 
> don't get into the 
> pre-made rough. But it may be something to watch for. Also, 
> the same second 
> set had nasty burrs by the sharpened end, so that it would 
> cut felt while 
> being inserted in the bushing (easily removed with a file or 
> sandpaper).
> 	As long as I'm on the subject, I like to replace the 
> rather bulky handles 
> with home made ones out of 1/8" dowel. This is plenty of 
> handle for the 
> purpose, and allows me to carry the set with me in a very 
> compact kit made 
> of a small square of firm corrugated cardboard - just press 
> the broaches 
> through the corrugations (don't insert in the corrugation 
> holes, go cross 
> wise and puncture each corugation). The square goes with my nice new 
> pinning tool by Mike Calahan (boy is it nice to have zero 
> wobble/side play. 
> Definitely my favorite purchase from the Dallas convention) 
> and pin nippers 
> into a small pouch made of mackintosh.
> 	One more thought: I sure wish there were two more sizes 
> in these broach 
> kits - up to 22 1/2 centerpin (.055). And I sure wish action 
> makers would 
> revert to starting off with 19 centerpins, instead of 20.5 or 
> so. Regards, Fred Sturm University of New Mexico