Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum No capstans and question about damper lift

My church has a 50 year old Hoffman upright with Herrburger & Brooks action. I tuned it yesterday lifting it from 415Hz to 440Hz. As I was in fear of breaking strings I did not overpull. As a result and in full knowledge that it would happen I spent five hours going back over it.

I have two questions the first is why might it be that there are no capstans? The key ends are felt covered and press directly on the wippens.

The second is what part of the action would cause every damper to lift immediately a key is pressed? It surely cannot be that every spoon needs bending?

Ian

There are usually flat-head screws under the back of the felt which are the lost motion adjustment.

If the nuts that hold the action on the action bolts are not tight, leaving the action further from the strings than intended, damper lift will be earlier in the keystroke.

Greetings,
It is not uncommon for damper felt to compress with age, allowing the spoons to hit earlier and earlier. You may find that bending the wires forward would be better than bending the spoons. Sometimes, they don't have room to come back far enough to allow the dampers to lift properly.

However, I would ask about the tuning. 5 hours is far, far too much time to spend in one session on a piano that is a full 1/2 step flat. A 1966 piano should easily be tunable, and I would far more inclined to pull it up to pitch with 8 cents over pull,(takes about 1/2 hour), then spend an hour and a half tuning. I am not sure what I would spend five hours doing.

Ed,

The nuts were tight and no evidence that the action bolts had been wound out.

Ian

Ed,

The dampers are sitting so lightly that some of the strings are sounding sympathetically. There is clearance at the sustain rod.

The damper felts have significant grooves as do the hammers.

My reluctance to bend the dampers wires was because of the grooves. I was thinking that the bending might result in uneven sideways pressure for the bi and tri chords. However I now realise that if I resurface the dampers I could bend the wires without the uneven pressure result.

I think the excessive time I spent was for three reasons.

First, my reluctance to overpull on each pass.
Second, the tuning was more difficult because of uneven hammer string indentations.
Third, the dampers were allowing sympathetic vibrations to affect my etd (my guess!) and the aural tuning of the choir outers.

I am well aware of the necessity to work to a proper regulation procedure before starting tuning but I made a fatal error which was to offer to tune before I inspected the piano.

I'm told that this instrument is little used and when I was told that the usual pro tuner has twice failed to turn up, I made my offer to tune it. From my inspection I can see that he has not been doing any regulation on it for many years.

Ian

Ian, the first thing to check is that the sustain pedal adjuster is not too tight, or that the rod is sitting correctly in the levers at both ends.

If not that, it is best not to start bending damper wires willy-nilly to increase the pressure bias to the strings. You will bound to end up with uneven damper lift and possibly confusing the desire to start adjusting spoons to correct uneven damper action. It would be best to systematically regulate the whole damper system from the start. Unfortunately, I think the descriptions given in the texts are not very adequate to do this. However I do remember that BDB posted a good upright damper regulation procedure at some point if he is reading this and wants to cough up!

Back to your original post: there is no part of the action that will cause only all the dampers to lift if you press a key.

Chris,

I said "The second is what part of the action would cause every damper to lift immediately a key is pressed? It surely cannot be that every spoon needs bending?"

I see what made you respond. What I meant was that on pressing ANY key, that key's damper lifts immediately.

So as learned here it looks as if the damper felt wear is the problem a full damper regulation is required. I have seen a You Tube video showing two extremity test dampers being adjusted then all damper spoons aligned to them. I guess much easier to do on a grand.

Ian

Manipulate the damper felt carefully?

However, flat treble dampers are not likely to wear so that they do that on 50 year old piano unless thay have been eaten. "V" dampers maybe to some extent if they become very squashed. It seems more like a fault. Are you sure that nothing is holding the damper rod from fully returning?

Chris,

I slackened off the pedal nut to make sure of some clearance between the lever and rod. It was the fact that any hammer movement starting the lifting that made me ask if there was something I was missing.

I should have taken some photographs of the damper felt to let those here judge the wear. I might still do that when next I visit.

Frankly there are other issues with this piano that has me hesitating to offer further regulation. The balance pin felts are very worn such that at least one key is slipping forward to rub against the key slip.

Maybe unknown to me, as I am new to membership of this church, the pro tuner had made an offer to regulate and was turned down and this maybe why he is reluctant to just tune it.

Replacing all the dampers would no doubt move the lift point perhaps even to its halfway position but I have a feeling that this action has more problems to reveal since I did see some hammers appear to wobble sideways.

I have no intention to tune and regulate any other pianos than my own but I am glad that I did make some effort with this one as it gave me an insight into what can confront you pro tuners every day.

Ian

Good plan. Leave this one alone.

With the pedal rod disconnected and the action in situ, slide you hand down to the damper lift arm and check there is a little movement slack before the dampers start to lift. If there is slack and all the dampers start to lift more or less at the same time do not start bending the damper wires as suggested - damper lift is normally completed as one of the first parts of regulation even before the hammers and levers are screwed onto the action beam, and not something to be messed about with unless you know what you are doing.

Regulating the damper spoons is much easier and is the very last procedure to complete.

Johnkie,
On hand lifting the lever just slightly all dampers lifted immediately and evenly.
Ian

Ian .. You haven't made it clear whether there is free movement in the damper lift when the action is in place i.e is it possible to feel free play (moving the lift rod both up and down) before any movement of the dampers?

The most usual cause if the spoons are lifting too soon is when the blow distance has been narrowed and pilots adjusted to compensate for the lost motion.

However, if the damper lift hasn't sufficient free play, either the action bolts have been interfered with, the lift support bushings are tight, or the felt pads located between the lift rod and the action beam is too thick.

JOHNKIE,
On the 25th I said there was clearance at the sustain rod.

Ian

Ian

Yes I know Ian, but that was the operating rod from the pedal rocker which is totally different from the clearance needed at the damper lift arm. When the action is in situ and the pedal rod is disengaged there should be an amount of free movement at the damper lift arm. If not the the dampers will bleed through at the very least, and the most common cause is usually someone fiddling with the position of the action bolts to adjust the blow rather than adjusting the hammer rest.

Best wishes John

John,

Now that is something new for me. Neither in my previous Knight upright, nor in my present brand-new Blüthner is there any free movement of that damper arm. With the rod disconnected, as soon as I put upward pressure on the lever the dampers start to lift.

I suspect we are at cross purpose in our descriptions. The only point at which there is clearance is, as I said, at the top of the damper rod before it lifts to touch the damper lever.

I'll measure the blow and see if it is around 47mm.

Ian

Ian:

I think you may not be understanding exactly what free play I refer to. There simply must be free play in order for the dampers to seat on the strings correctly.

Are you removing or partly releasing the action to test for the free play ?

The action must remain fully installed and bolted in its normal operating position, the pedal rod either disconnected or the adjuster slackened off. and then passing your hand down between the action end and the casework, grasp the "L" part of the damper lift rod and check to establish that there is free up and down movement felt on the "L".

I certainly don't accept that either your previous Knight or New Bluthner upright didn't have this crucial free play, otherwise you would have experienced real damping issues

A remote possibility is that the action is not sitting correctly on the mounting studs. This can happen despite being able to tighten the brackets on some pianos.