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Posted By: Numbered Looking for some information, please! - 12/12/17 05:42 PM
I read a thread some time ago which had, if I recall correctly, info about upright damper regulation on the bench, not inside the piano. I think it was a technique that Bill Bremmer was speaking about and in which Mark.R commented.

I have searched high and low and cannot find it.

If anyone knows where I can find it, please can you let me know?

Thank you.
I know the technique you are talking about. It is best used with the piano action in a cradle but not entirely necessary if the action will stand upright on a flat surface. Not all actions will.

What you are talking about is the damper spoon regulation. It is the most difficult part of vertical action regulation. Generally, it is not needed if you have the correct blow distance, key height, dip, etc. Therefore, if you find yourself in a situation where all of the spoons need to be adjusted, you have probably made the blow distance too short and that is the reason why all of the spoons are lifting the dampers too early.

When a vertical action is properly regulated, the jack will trip out just enough to clear the hammer butt and as soon as pressure is released from the key, the jack will pop back under the hammer butt. If you can see that the jack flies out from the hammer butt and leaves a large gap, you have far too much after touch. When you slowly release pressure upon the key in such a situation, the hammer will collapse back to the rest rail and the key will not repeat until it is fully released.

Most brand new vertical actions are actually set up this way. That is to allow for the compacting of all of the material that supports the hammer blow distance. There is the rest rail cloth, the hammer butt material and the keyframe back rail action cloth. They will all compress over time. The manufacturer builds in a short blow distance but expects all of the material to compress and only for the technician to have to fine adjust the capstans for lost motion and to tweak the let off buttons to return the let off to about 1/8" inch.

For the most part, this works for vertical action regulation maintenance. Let me say that a vacuum cleaner, a screw driver for tightening flanges, a flange spacing tool for the combination handle, a capstan tool (either pointed or open end wrench type), let off regulating bit for a combination handle (there are two types) and a straight edge (just a common ruler will suffice) are all that you need. They were given in order of importance. You would need some balance rail punchings for key height and front rail punchings for dip and maybe a dip block but really to have to straighten out a keyboard is rarely necessary.

The most common mistake made is to read in a set of instructions to set the blow distance first. Theoretically, it is correct but practically, it is the worst mistake you could ever make in most circumstances. For one thing, how you actually measure that distance may be totally bogus!

Your goal in properly regulating a vertical action should be to change everything as little as possible, not cranking every screw multiple times. The spoons were set at the factory to be correct. So were the backchecks. If you find yourself having to change either of these radically, you have probably done something wrong.

Nevertheless, there are still circumstances in which the spoons must be adjusted. There is a spoon bender tool for that and it requires removal of the keys. I must admit that after all these years as a piano technician, I could never learn to use one effectively. I have seen technicians who could and my hat is off to them.

The technique to use in the case where all or most of the damper spoons need to be adjusted is to get an end key, such as the highest note of the middle section to work properly by hook or by crook (or find a key where the damper lifts correctly and use it as a model). This can be done by tilting the action back and adjusting a single spoon with a damper wire adjustment bit in the combination tool handle, adjust the spoon, replace the action and try the key until you have the proper adjustment: the damper begins to lift when the hammer is about half way to the string. If you have any key that actually works correctly, use it as the model.

Then, as the case may be, place the action in a cradle or on a flat surface, take a hard, wooden wedge and place it between the damper lifter rod and wedge that rod to the point where you have the one correctly regulated spoon and the hammer and damper lift simultaneously. Now, regulate all spoons with a damper bending bit in the combination handle so that ALL hammers and dampers move simultaneously.

This, of course depends upon whether the lift of the dampers is sufficiently even. If that is not the case, you have a far more worse problem to solve but if you solve it, you may well find that the damper lift with spoon is solved. They are definitely interrelated.
Posted By: Numbered Re: Looking for some information, please! - 12/14/17 07:16 AM
Thank you for your response Bill, but I am looking for a technique to adjust the dampers on the bench, not the spoons.
Posted By: Beemer Re: Looking for some information, please! - 12/14/17 03:05 PM
Originally Posted by Mark Davis
Thank you for your response Bill, but I am looking for a technique to adjust the dampers on the bench, not the spoons.

Mark,

I recall seeing a YouTube video of a factory technician doing what you are looking for. He had a mock-up string choir set (for one note) on the bench sitting behind the bench mounted action. My guess is that it would only be used to set the vertical alignment to ensure top and bottom felts presented the same pressure. As the angular and rotational setting would have to be done in the piano I cannot see much advantage of using the jig.

Ian
I guess you could get close by first getting the end dampers of each section aligned and then using a straight edge. But sorry, I don't know of any specific technique. It is important to adjust them so they lift simultaneously with the sustain pedal before moving on to the spoons. Sometimes the sustain bar needs some work, too.
Posted By: BDB Re: Looking for some information, please! - 12/14/17 03:43 PM
You can set the end dampers, as Jeff said, and then prop the damper lifter bar up so that the levers are all resting on it instead of the spoons, and then adjust with a straight edge. You will need to do final adjustment of the wedge dampers in the piano.

You can adjust the spoons by setting them to lift slightly early, then bend them back by holding the lever as you lift the wippen.
Posted By: Numbered Re: Looking for some information, please! - 12/14/17 04:52 PM
Thanks to all who have responded!

I was thinking that apart from actually aligning the dampers to the strings while the action is in the piano, that there may be a way of adjusting the damper to pedal timing on the bench that is faster than the way I am doing it the piano.

I have checked out my PTG journal Cd's that I bought several years back, years 1979 to 1999, and have found some articles written by Jack Krefting that are very helpful. I am going to just push ahead with damper regulation in the piano.
Posted By: Numbered Re: Looking for some information, please! - 12/15/17 07:35 AM
Found an article by Bill Spurlock "Vertical Damper Replacement" which explains in it the procedure of adjusting dampers on the bench.

Trust the article will help those who are interested.
Posted By: Beemer Re: Looking for some information, please! - 12/15/17 03:14 PM
http://www.spurlocktools.com/index_htm_files/vertdampers.pdf

Ian
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