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I acquired an old 1910 Hardman/Peck 6’8”grand a couple of years ago. I have been doing my own work on it using the Reblitz book as my primary source of information. I have had some trouble particularly in the bass section getting the let off set to 1/16 inch. I am trying for hammer travel of 1 ¾” and key dip of 3/8”. I run out of key travel before I can achieve let off of 1/16”. Some keys are worse than others and I find that I either have to increase the let off distance or reduce the hammer travel. (I am trying not to increase the key dip)

I recently got a tech to look at it in hopes of getting some help. His assessment was that the repetition springs were set to strong and asked me to readjust them which I have since done. He also asked me to go over the regulation using his usual specs which are setting the hammer travel at 1 ¾”, the let off at 1/8” with the hammer drop 1/8” below let off or ¼” below the string. I have gone through the action using these specs fudging here and there. I am still having some trouble in the base achieving ¼” let off and some after-touch. He is going to come back and check it over. The tech has a lot of years of experience and has charged me nothing for his help so far.

When I asked him about his usual specs deviating from Reblitz, he said that he liked to have extra room so that he would not get a call from half way across the state two weeks after he had been there and the weather had changed resulting in a hammer jamming against the strings. I can certainly understand that.

I also understand that the Reblitz specs may be a general ideal and that reality may vary. My question is, is the deviation mentioned above a realistic norm, and what is sacrificed in making this kind of deviation? I have up to this point tried to stay pretty close to the Reblitz specs with modest fudging.

Thank you

When an action is worn 3/8 key dip might not be enough. Pick one key, increase the dip till it lets off. You might not be able to acheive 1/16 let off - the hammers are likely not as large as they were originally due to wear and hammer filing. You might have to settle for 1/4 inch or more let-off. The fix is new hammers and shanks, which should get you closer to spec.

The springs might be too strong but that's not the source of your problem

This piano should be a good quality piano - It's worth spending a bit of money on it.

Thanks Bob,
I agree with the tech that the springs were too strong but I coudn't see it affecting my problem. I had increased the spring tension previously to make sure my problems were not caused by the hammers pushing the repitition levers down from thier weight and I over did it. I got the impression that the springs were the first thing he noticed and decided that we should get them right for starters.

The piano had new hammers installed in 1990. Looks like the old shanks. I was told that the new hammers are either renners or Yamaha. ( I think that they are probably too hard for this piano.) The knuckles look old and I have wondered if the flattened knuckles may be the problem. I cleaned up the knuckles with nafta and mineral spirits and tried to shape them up a bit.

I have been pondering the idea of replacing the hammers with a cold pressed hammer.

I don't mind taking things one step at a time with a professional tech and making things right. It may give me time to get to know him and validate what we do along the way. Hope no one minds if I use the forum here for some of that validation.

It could be that that piano was meant to have less that 1 3/4 inch blow distance. Also, did you bed the keyframe? Key height can also be a factor.

While Reblitz is one of my favorite bathroom reads and I find his info to be a great general overview, I wouldn't take every measurement of his to be gospel.

If you change hammers again certainly get new shanks. You'll be surprised at how shanks can effect tone. New knuckles are a darn fine thing:)

PTG may be able to find the exact specs for your piano.

Happy rebuilding,

Brad,
Thank you, I did bed the key frame or went through the motions. I may have to recheck it. It seems like as much art as anything. The Hardman was built with an iron frame on the underside of where the action lays and appears to be pretty stable. That is if you crawl under the piano and look up beneath the action section. I don't know if other pianos have that iron frame.

How could I go about finding out if the specs for my piano are available through the PTG?

Thanks

You may have hammers that are bored improperly in the bass, if they have been replaced. You may be measuring wrong. It is difficult to tell over the internet.

Hardmans used Wessell Nickel & Gross actions, which use standard regulation numbers.

When I regulate a grand piano, I set the let-off on the end notes of each section so that the hammer lets off when it touches a piece of 1/16" wire between the string and where the hammer would hit. If need be, I raise the hammer until I get a good aftertouch on that note. Sometimes I need to lower the drop, too. The let-off is independent from all other adjustments, so I can use those notes to set a let-off rack, and make all other adjustments from that, i.e., drop is 1/16" and hammer blow is 1-11/16 below the rail.

Don't worry about specs. They probably will not work for your piano.
At 3/8" dip you have room to increase till you can get letoff drop and aftertouch at some blow distance. It may never be what you want unless you do some modifications.
You cannot judge repetition spring tension until letoff and checking are established. For now just have enough to support the hammer assembly.
Be sure to maintain jack/knuckle alignment and rep lever height as you make changes.

Thank you guys,

If the ideal specs are deviated from, is it better to make that deviation just on the notes that require it, or should the whole action be regulated to that deviation?

BDB, You said:

By this I assume that you raised the capstan and reduced the blow distance?

Thank you

Hey Craig,

Here are the specs from the piano action handbook
key height 2 7/16
hammer blow 1 3/4
let off 1/8
key dip 3/8
back check dist 9/16-5/8

Remember that these were the numbers for new, unworn parts. Your mileage may vary...

Here's a trick that may help you:

set the key dip so that the back of all the keys (or the capstans) move the same amount. Once that is consistant, you have a better chance of getting consistancy all the way up through the rest of the action.

The final feel is the evenenss of the aftertouch. If everything is very close, you can "cheat" the hammer line (blow distance) to achieve an even touch.

Ron Koval
Chicagoland

That is correct.

Incidentally, the 3/8" key dip is measured at the keypin, not the front of the key. That according to Aeolian American, who inherited all these old action manufacturers.

Thank you for the specs Ron and for this idea:

It hadn't occurred to me that I may be getting different travel distances at the back of the keys or at the capstans. Each key being a lever, any variation in the geometry of the levers such as fulcrum position (at the balance rail) for example would result in variations of travel at the ends.

Thanks

BDB,

I have been using a little tapered block I purchased to set the dip. I had been assuming the 3/8" was at the front of the key, interesting information.

I have received quite a bit of info from this thread. It may take me some time to investigate it all. I appreciate all the help.

Let off theoretcally is graduated from 1/16 in the treble to 1/8 in the bass and more on the unichords. It has to do, I believe, with the amplitude of the string in motion being greater in the bass.

Make sure the keyframe is bedded properly even when you step on the pedals before proceeding.

I don't like a 3/8 dip, I feel cheated when playing. .390 at the keypin is nice. Yamaha measures .394 or 10 mm at the front of the key which is about .375 or 3/8 at the pin. Set the dip. Leave the blow distance at 1 3/4. Make sure the rep spring is working and drop is more than needed and set letoff. Letoff is an adjustment that won't change when you adjust the others. Set the jack to knuckle position. Now bring your backchecks into play, that changed with key dip, and set the check distance. The back checks affected the rep spring so set that again unless you were lucky. Check the rep lever height because that will be affected or affect the spring too. If you weaken the spring, the jack starts to rise up through the rep window. Make a refinement pass though the whippen adjustments.
Double check letof in the piano if you set it with a gauge the set the drop screw so the rep lever contacts the drop screw athe same time as the jack contacts the letof button. It feels like platform. If there is too much drop it will feel mushy through letoff with extra resistance or if it's too little drop, letoff will seem to accelerate through aftertouch. Now set your blow distance for the proper aftertouch.

Do the whole procedure one more time, checking every note.

Thanks for the additional information Keith like some of the finer details of the drop screw adjustment.

Although my first attempts have taken huge amounts of time my results are probably pretty rough by professional standards. Given that, the piano has seen considerable improvement from when I got it, which has been rewarding. I plan to keep running through it working out the bugs in the piano and in my understanding of it.

I am going to print this stuff out and save it.

Thanks