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Jeff,

Thank you for your honest and uncondescending advice. You're right about the action probably being loose due to it's age. I didn't think about how that would affect friction. I like the balance punching idea. I've had lots of ideas and lots of time to contemplate them all. I believe the best approach for this piano and my client is to replace the hammer springs.. check the touch, then possibly half the punchings like you suggested.

Thanks again.

Marcus:

On a grand, the weight of the hammer affects the downweight in relation to the action ratio, but on an upright not as much because the hammer moves mostly horizontally. I think 45 grams or so on an upright will give a similar feel as 50 grams on a grand. And the downweight should be lighter in the bass. A difficult place to get the feel right is across the break where the weight of the hammers change. The change can be a great deal on consoles and spinets if the hammers are narrower to allow clearance due to side angle. Don’t be afraid to make adjustments to the downweight on an upright based on how it feels. Yes, replace the hammer return springs. And if you want the action to be consistent repin the hammer butts and rebush the keys.

Yeah Jeff, that's interesting. If the spring tension is not even, the weigh off becomes random, note to note. Sure you even the DW but then the mass is not evenly placed and that gives a difference in feel from key to key. Like the Samick grands with wippen springs. Some of the springs are set too heavy and there is lead in the back of the key. If you use a spring to assist, to have to lead to reduce the assist is stupid.
So by weighing with the springs engaged, the lead is compensating for the spring varience and not the mass of the system. The positon of the lead in the key affects the rate the key rocks back and forth. Most grands will have a pattern that reflects the varience of mass in the key and hammer. To me the evenness of mass is as important as DW.
F=Ma. If the force, F, is the same from note to note, as the mass get lighter, the acceleration increases. The finger hits bottom sooner.

BDB,

I don't understand

I'm talking about regular old touch weight, not some other, non-standard definition. The jack spring pushes up on the jack but the jack is stopped against the hammer butt felt. The jack spring is also pushing down on the wippen and thus down on the back of the key.

A stronger spring will require more weight at the front of the key to get the key to go down when doing touch weight mesurements.

This seems to be tricky to describe and difficult to visualize in your mind. Please experiment and you will know what I'm getting at.

When the action is at rest, the jack is a stick that goes between the wippen and the hammer butt. It does not matter whether there is a spring there or not. The spring only changes the force against the key when the jack arm touches the button. So the strength of the spring has nothing to do with the touch weight.

I'm surprised nobody has mentioned "Jiffy Weights". These are the rather large weights that screw onto the back of the keys. They have a few advantages:

1. easily reversible
2. relatively inexpensive (around $40-50 bucks a set)
3. Quick to install (no holes to drill in the keys
4. Because their large size they install closer to the fulcrum thus causing less inertia for the same touch weight effect, than a smaller lead farther toward the end of the key.

Drawbacks:

1. if installed too close to the capstans they can make adjusting them challenging.
2. They look kinda cheesy.
3. Lead is toxic and I keep hearing that manufactures are going to be moving away from using lead in actions.

I have found that "individually leaded keys" that some manufacturers brag about can have very random leading patterns. This tells me they are also not paying much attention to friction and other factors that affect the down weight.

BDB,

Try to imagine where the spring tension is going. One end pushes against the hammer butt felt. But the spring also has to push in the opposite direction which is against the wippen. Since the wippen rests on the back of the key the force of the spring effects the pressure of the wippen on the back of the key - which in turn affects the touch weight.

Just for fun, I just took an action model and measured the down weight with jack spring in place: It was 54 grams to get the front of the key to drop. With the spring out of place the down weight dropped to 40 grams. That's quite a difference!

I had a hard time understanding the jack spring's role in touch weight too. It was a Steinway console that finally opened my eyes. The piano had weights in the FRONT of the keys. I was trying to adjust lost motion and was pulling my hair out. On many of the notes when I would try to introduce a small amount of lost motion the key would follow, messing up the key leveling and removing all the lost motion. This was a serious hindrance to the repetition.

A previous technician had diagnosed it as a key weighting problem. As it turned out, when I installed a new jack spring in one of the wippens the problem was suddenly solved.

Since the jack spring is only in play after the key is depressed most of the way, wouldn't that only effect the touch at near the end of the key stroke.. and not the initial downweight?

There might be a tiny effect of the jack spring as the angle between the base of the jack and the notch in the butt changes. Definitely no effect on grands.

I have jiffy leads that I have removed from pianos. Removing them was a big improvement in the touch.

I thought about it, Ryan, but I've never used them except on cheap old verticals with an isolated key or two that won't return properly. I'm interested to know what other techs think about using them more extensively, particularly on better instruments.

A couple of things I do with them are: Cut them in half when that much weight will do the trick, and screw them onto the bottom of the key whenever possible, which does away with the cheesy appearance factor.

Jeff

On a grand the jack spring has no effect on the touchweight. This is because the jack stop cushion is on the wippen. On an upright, the jack stop cushion is on a different action rail than the wippen.

I wouldn't call 10 grams of added down weight "tiny" Did you read my last post? Haven't you come across console pianos with weak jack springs where the lost motion is impossible to adjust?
Please, please, take the measurements yourself so you can convey accurate information here. A little scientific study might make the light go on. Measure downweight with and without a jack spring. Apparently, I'm unable to describe why the spring has a substantial affect on downweight to you, but if you take the time to study it yourself you may get a handle on it.

My other theory is you're trying to drive me crazy! <font size=1> it may be working!</font>

10 to 14 grams of DW. No, it is not little.

The tip of the jack is pushing against the hammer rail. This is trying to force the wippen down and the force in grams of DW is????
a) 0 grams
b) 1 gram
c) 100 grams
d) 10 grams
For 1 million dollars, is d) your final answer, Ryan?

On my Young Chang action model the jack spring added about 14 grams. On a new 52" Heintzman the spring added about 10 grams.

So for the big money I'm going with "D"

Did I win???

Bonus question: On the above mentioned action model how many grams of down weight were added by placing a Jiffy lead just behind the key button?

a)5 grams
b)9 grams
c)13 grams
d)17 grams

This is for 50 shares of Ford stock!

Ryan:

I never realized the jack springs would make such a difference. Thanks!

I agree. I will conduct an experiment of my own. I've learned hear that grands touch weight has more to do with gravity and weight than verticals. Verticals has more to do with the springs.. inherent in their design.

Ryan, how do you manage to put in those extra little goofy guys in your posts anyway???

Don't tell him Ryan, his posts are already goofy enough.

It depends on how much the jiffy lead YOU use weighs.
a)5grams

I do not have an upright that I can experiment with here.

A wore of warning. New springs relax a bit after they are installed, so if you try to do too much with them too soon, you will not get consistent long-term results.

The new Jack springs that were developed by John Rhodes, RPT of Portland Chapter have many more coils which has improved longevity and stability of the spring. He also had the center portion of the coils touching each other so that the springs don't become entangled.



Schaff is selling them.