I just soldered a broken repetition rail at C 88 because the hole for that stack bracket was not aligned when a new key set was installed. The bracket screw, when installed, forced the action bracket away from the repetition rail and broke the solder joint. After soldering the joint, I plugged the errant hole, and drilled a new hole that matched the bracket location. Just like new!

That's because its a non-parallel strike line action, that is, the strike line is not parallel to the key fronts.
Whew!
An understatement...it is an arcane design. It has some good points but the rails and the rail profile creates for me, shall we say, job security

Jim Ialeggio

Thanks Jim.
I'm just wondering, how would you say the Hamburg steinway action compares to the NY ones?

Ok it.s 6:50am here, i must be still a bit tired!-Why does a non parallel strike line mean that the front rail must be thicker in the bass than in the treble?

Greetings,
I think what was meant was the balance rail has to be lower under the longer keys to keep a constant relationship between the whippen centers, capstan contact, and balance rail. To effect this, the longer keys must be taller.
Regards,

Ah i see, ok thanks Ed...Good to see you are not being censored on here!

THanks Ed, this is what I was referring to.

However, as I thought about this during the day in relation to Musicbased's comment of a thicker keyframe frontrail in the bass, it really doesn't compute. I can see no reason for the frontrail dimension to change...balance rail yes, but it would decrease...but front rail??

Add to that I haven't seen S&S taper the balance rail for B's & D's. M&H does, at least under Bruce Clark, but have you seen other manufacturers address the tapered balance rail?

Jim Ialeggio

No, Jim, I have not. And to tell the truth, until Bruce pointed this out, I had never considered the concept! Once it was drawn out, it was clear. I personally think the congruence of whip center, capstan contact, and balance point is important, but favor the alignment of the three to occur at let-off instead of at half-stroke.

This comes from my understanding of "gain geometry", reinforced by Del's opinion of sliding motion being minimal (if I understood him correctly). When I get the time, I intend to come up with the numbers,but I do know that the action ratio changes during the keystroke, and I don't want it to be decreasing during the latter half.
Regards,
I will have a post later about the four day WNG class in Haverhill. After formal training and 36 years of this work, I was still treated to at least one epiphany a day!

Looking forward to your report on the WNG class!

A New York B is a parallel strike and all the keys are approximately the same length.


Ed Foote ... Are you in Haverhill now??

Larry, do you know why the keyframe front rail might be 2.5 mm thicker in the bass than the treble?
Setting the dip on this is weird, in the bass i can only just get enough dip with no paper punchings, but in the treble i need loads!

Hi Larry,
No, I was last week, and realized that your place was just one floor above Jude's shop when I went by there. Wish we could have met, but perhaps in the future!
Thanks,
Ed

I apologize, I don't have a good answer for you. I can email someone at Steinway NY and ask. You can do that as well. Kent Webb is a great source of information as is David Kirkland.

I don't have either of their email addresses here where I am. If you would like, I will put my hands on them and send it to you.

Ed ... Yes. Thank You ... I missed your evening at Steinert's, I apologize. Bill Shull pulled me to San Antonio TX to help document an 1858 Steinway Grand ... All original with the original Henry Jr. Action ... all original ... How could I resist ??

Thats ok, thanks Larry. Yes i did email Kent when i first had the initial action twist problem.
He replied wanting to know the serial number, so i sent him that but he never replied after that!
I'm sure he's very busy.

I'm just curious really as it seems to work alright anyway, it just looks weird!

Thanks very much again to everyone who responded, it's actually turning out to be a very nice piano despite all of it's quirks!

the height differnce I noticed was at the balance rail, (plus satck height) and the front rail was following, but it was a 2 mm range maximum between basses and high treble (with key leverage variation between basses and treble) . I dont recall on what models.

Regularely noticed a HC heigh varying (as WC) 1 mm +- not more.

When the keys have a progressive ration, the action position is lightly tweaked (1 mm range) so the "mid blow" is respected (a little later, as said Ed, the acceleration can lower after the beginning of friction moments for let off) ... we may imagine that none of the parts are rigid, that makes more difficult to visualize what happens, but it can be felt if you have a pianist hand)

But some actions are setup with no acceleration but the one on the shank (there the leverage varies much between rest and let off position)
The action at rest have the capstan whippen heel is located on the line of centers (I dont know the exact geometric terminology)


It is supposed to adsorb better the different friction moments (dampers, drop/let off) more progressive touch.

I am not a big fan of this setup, but I can understand the idea. I believe it is just a trend...

I'm up at Haverhill as we speak all this week for the WNG class as well. As expected the use of the action parts is being really well clarified and expanded upon. But, as usual, the informal unexpected chats among the techs Bruce and Kirk Burgett, today about things belly-wise, have been the unexpected traded gems.

Very enjoyable.

Jim Ialeggio