Upright Hammer Shank Length

[Ron Nossaman]

Farrell wrote:
> I'm installing a new action in an upright. I need to find the "sweet" 
> spot up at C88 to determine how long to cut the shanks (determine strike 
> point). Doing this on a grand piano is so easy by sliding the action in 
> and out a bit and the hammer assembly can be glued nice and firm for 
> good sound production.
>  
> Does anyone have any suggestions on how to do this on an upright? If you 
> move the action, the regulation changes, and if you have the hammer 
> mobile, I fear it is too loose to really get a good sound. How do you 
> folks do make this determination?
>  
> Terry Farrell

It's been a while, but here's what I did last time I did one. 
Hammers in a jig clamp, glue in shanks. Pre-travel butts as 
you wish with another set of shanks while the glue dries. Take 
end shanks and hammers to fit to butts. Poke strip of acetate 
into, uh, the hole the top end shank will go into. This will 
provide a tight fit while you test hammer height by sound. 
Trim and fit, trim and fit until you like the sound. Discard 
acetate. Put hammer and shank back in the jig with the rest of 
them and mark all the rest a millimeter or two shorter than 
the guides. Trim the marked shanks to length. Glue in the 
guides, bottomed out in the - hole and squared up for straight 
travel. Tape a straightedge to the underside of the back of 
the moldings. Hang the rest of the hammers, not bottomed in 
the holes, but resting on the straightedge. I do whatever 
shank whittling is necessary to line everything up with the 
strings a section at a time, then just pull the shank and 
hammer, dip the shank end in stickum of choice, and put it 
back in the hole. Align and travel, mop slop, move to next 
one. There'll likely be some burning in later as the glue 
dries and pulls the shanks around some, but it's worked pretty 
well for me.
Ron N