Hello Piano World gurus (or not ;)),

This is my first post. I am a young full-time tuner / tech. I've been tuning pianos since 2007 and have been adding skill sets, buying tools, and trying to gain customers as I go along (minor repairs, then upright regulation, bigger repairs, etc.). My instructor has been Art Reblitz's book, and these forums.

Now I am in the middle of my first grand regulation. It is a 6' 4" 1937 Kimball. I have leveled the keys, set the key dip, aligned the jacks to the knuckles, and set repetition lever height. I started to set hammer height to 1 3/4" blow, but as I was turning the capstans out a WHOLE lot, I thought, "I probably shouldn't be having to make this much adjustment. What am I doing wrong?" I then found out that 1 3/4" blow put the bass hammers at 6 1/2" above the keybed, which is a problem because the pinblock makes the action compartment opening only 6 1/4" tall.

Anything I should know about the effects of increasing the hammer stroke to 2"? Or about grand regulation in general? Remember I have done full upright regulation, but this is my first grand.

Al:

Welcome Aboard!

I don't do much grand work, others will surely chime in, and I look forward to what they may post.

My first thought is about leveling the keybed and just where you are taking these measurements from. My second thought is what blow distance will be best in way of aftertouch.

I would think there is considerable wear on the hammer set; this is why you have to raise the capstans so high in order to find the correct travel distance.

What were the measurements previous to beginning the work? Go with 1 7/8 and sneak the hammers under when you replace the action. Usually after regulation on a used grand of this age the capstan height falls away in the first couple of weeks if you have shaped the knuckles.

With no new parts or felt I usually take the measurements of the top three keys. These do not have much weight and the parts will not be as worn as the rest of the register. You can usually take those measurements and set up the action in an artisan fashion.

Remember that with a used action of this age, the regulation measurements can only be used as a guideline, unless the action/keyboard has had all of the felt restored.

Silverwood, I think some felt has been replaced since 1937, including the hammers. There is a message penciled on the key frame that says "Z. Huang" "reconditioned" and "regulated action" back in 2004. I am not sure if Z. Huang did it correctly, though. I had to replace the old plastic key tops because they were glued improperly. (By the way, the new key tops have the same thickness as the old ones.)

The upper three hammers were resting about 2 1/8" below the strings. Since posting my first post, I have regulated all the hammers to 2" blow.

I still would appreciate any more advice you guys have for a first-time grand regulation.

Welcome to the world of regulating crummy actions!

How are you measuring the hammer blow? Two inches is rather extreme.

My first questions would be:
How did the piano play when you first encountered it? What were the regulation dimensions - did you take notes of any of this?
Have the hammers been replaced at some time (possibly with dimensions deviation from the original specs?) or are the hammers original (how much wear on the originals?)

One time saving tip: regulate all the adjustments of one key, play with it until everything works out, then copy it to the whole keyboard. This will save you from un-doing an adjustment 88 times if you are off.

If you really want to become proficient at piano technology, you have to move far beyond the one book and an online forum as your teaching sources. Make contact to local technicians, find a mentor, get some real training by attending a PTG convention (they are open to non-members). I think those who can successfully learn to tune and service pianos from a book are about as rare as hens' teeth.

You don't say if you have adjusted the action glides (studs) yet. That should be correct before messing with anything else. To answer your other question, a 2" blow might require a deeper key dip if the let off is set close to the strings. Or a 2" blow might increase let-off distance without a deeper key dip, or the action might have needed a 2" blow when new. It wouldn't hurt to find a tech who will spend an hour with you and this action.

Supply, I didn't play the piano with the knowledge that I would be regulating it, nor did I take any measurements. Those are things I will definitely do next time. The hammers look like they have been replaced, and they have minimal wear (1/32" grooves with no filing indications).

Thanks for the tip on adjusting one key before everything else. I will play with that for a little bit before I go on.

Bob, I have adjusted the glides. I also have just set let-off to 1/16" and there is still plenty of aftertouch, in my opinion. Isn't it possible that the action was designed to have a 2" blow?

I will consider calling a more experienced tech, but I'd like to try to troubleshoot it myself, first.

BDB, Yeah, I realize that there are plenty of crummy actions to massage into submission.

I am measuring hammer blow with the Jaras let-off rack. I also slid the action into the piano and measured with a ruler between the strings just to be sure I wasn't making a measurement mistake with the Jaras rack.

The technician who worked on the piano is most likely Zhiwei Huang, who is living in the San Francisco Bay area, I believe. His email is goldenoteh@yahoo.com. Maybe he would be able to tell you something about the piano. He is a very gracious person and would love to talk with you.

By the way, Zhiwei is teaching 2 voicing classes as the Westpac conference coming up: Angel Shot voicing, and Voicing without needles.

There is a Mason & Hamlin in my town that regulates with a 2" blow distance and a 3/8" keydip. Needless to say it is a heavy action. The only way to fix this type of problem is to change the action ratio - move the capstans toward the player or the knuckles away from the player. If the piano had the hammers and shanks replaced I would suspect the knuckles.

I recommend regulating the action in the piano as opposed to on a work bench. Anything you can do on a workbench you can do in the piano with some practice and the right approach.

The problem with this action is that the hammers need so much distance to fit under the pin block. The action ratio has nothing to do with that.

BDB: You're right!

Alexander,
If you set the blow is to 1 7/8" will the action come out without the hammers binding?

You seem to be working it from the top down. It's usually better to regulate from the bottom up. Might want to put the ruler away for a while too.

Sowers, Yes, the action will slide out without the hammers binding even if they're at 1 7/8". They just get depressed a little as they pass under the pinblock. It just doesn't seem correct -- why would they design an action that way? Unless the pinblock was replaced, but that's unlikely.

There is one other problem that I haven't mentioned yet. The drop screws were turned all the way up to the stops (i.e. the position that allows smallest hammer drop) when I got the piano. Even unscrewed to the highest position like that, the hammer drop is still too much (i.e. too low).

Thanks for Huang's email by the way. I sent him a message. I also am going to see if I can get a technician who I know has extensive action experience to come take a look on Thursday.

It happens that the bass hammers on many pianos barely clear the pin block, or even touch it slightly. Some Kimballs actions were made for a 1-7/8" blow.

If the hammers are just slightly scraping the pinblock on action removal, that's not TOO bad.......Just set the blow at 1 7/8 if the ratio will handle it. Sounds like it will.

Ah, sounds like the knuckles have been replaced with ones that are not quite the same size. (damhik...) This may have been the result of replacing the shanks with the knuckle positions also being different from original, resulting in a different action ratio and allowing such a large blow and still with adequate aftertouch.

Of course this does not explain why there is so little clearance between the bed and the pinblock. In which case I wonder why the drop screws are not digging into the pinblock, being up so high.

Don't mind me too much, I am mostly musing out loud.

UnrightTooner, The drop screws just barely clear the pinblock.

Make sure all the action frame screws are tight.

Grand action work is difficult enough for a beginner when everything is in the correct ballpark. (Even then - remember to take careful notes and measure everything before you even begin!)

There seems to be a number of things about this piano that are off the mark. While sight-unseen advice, speculation, guessing, and musing is fine and dandy, what you really need is someone who knows their way around grand actions to come in, look at the issues and properly diagnose what is going on.

I just saw this thread. Contrary to what all of the books say, I set the blow distance last, not first and I never measure it. When the key frame is fitted, the key height, dip, let off and drop are correct, the best blow distance is found when the proper amount of after touch is found. Any time you think you have to turn up the capstans any more than a a crank or two, put this image in your mind: that big red sign that says "Wrong Way" as you are making a turn onto a highway.

I don't know where you got the 1 3/4 spec from in the first place. For grands, it is usually given as 1 7/8.

The best way to find the right after touch after you have all other regulation dimensions set is to take a .030 card front rail punching and put it on top of the Middle C (C4) front rail punching. This is best done in the piano rather than on a bench. Adjust the capstan of that key until there is zero after touch. Now, do the same with all of the C's and F's. You will then find all of the C's and F's at an average height. Adjust all of the capstans to that height. The result may well be in this case that the blow distance is close to two inches.

I suspect more than anything else that (as Jeff mentioned early on) the way you are taking the measurement is the problem. If you do the capstan adjustment the way I suggested and then take a measurement, you will probably find that it turns out to be within the range that it should be.

Thanks Mr. Bremmer, your post was helpful.

I called out a tech with 30 years experience, and we determined that the new hammers were incorrectly bored, resulting in hammers that were too short. This also caused the drop screws to run out of travel. Also, the action design by Kimball might not have been optimal to begin with.

Since the drop was inherently so low, I ended up setting let-off to 6.5 mm to minimize drop. Even with that much let-off, some of the drop screws were topped out. (Crummy action? You bet!) Key dip I set to 9.5 mm, and blow distance to 1 7/8".

Thanks you all for your input, especially those who recommended I call out another tech. I now have a much better understanding of grand actions.

This is more or less how I was taught to do it. However, the shop I learned grand regulation at used proprietary benches that allowed us to index everything, including after-touch. Once the bench was set up, we would rough-in hammer blow to, if I remember correctly, 47mm. After all the other reg steps were done, we would go back and set after-touch using the method Bill describes, though our standard spec was .047" @300g (more after-touch than I like).

Glad I could be of help. I suspected what you said, too short of hammer bore. While it may be a compromise, one thing that could be done in such an instance is to shim the stack higher. That is, to place some front rail card material under the feet of the action stack such as some extra thick (.060") material. Trim the material so that is no wider than the feet of the stack.

One change like this will, of course, affect other adjustments. The screws that hold the stack may not tighten, so you would need either longer screws or do something to shim the screw holes so they will. You can put in thicker back rail cloth or put some card material under the loose end. That would mean fewer front rail punchings to get enough dip. If the knuckles (rollers) are flattened, they can be bolstered. All of the above would reduce the amount you would have to turn up the capstans, give you closer let-off and allow you to have the proper amount of drop.

The best solution for someone like you however, would be to get a new set of pre-hung hammers from a shop like Pianotek or Wally Brooks. The new hammer shanks would have new knuckles too. You would just need to make sure the shop knows that the samples you send have a too short bore and that they should supply new hammers with the correct bore length.

You can then use the same technique I described for the final adjustment of the blow distance. I learned it at the Steinway factory in 1986. Those instruments sometimes have dimension problems too, so rather than measuring the blow distance from the string, the technique I described is what they do. They also manipulate the back rail cloth the way I described as well (but with veneer) and as a last resort, shim the feet of the stack as I described (but usually with some glued in veneer).