2017 was our 20th year online!

Welcome to the Piano World Piano Forums
Over 3 million posts about pianos, digital pianos, and all types of keyboard instruments.
Over 100,000 members from around the world.
Join the World's Largest Community of Piano Lovers (it's free)
It's Fun to Play the Piano ... Please Pass It On!

Shop our online store for music lovers
SEARCH
Piano Forums & Piano World
(ad)
Best of Piano Buyer
 Best of Piano Buyer
(ad)
Faust Harrison Pianos
Faust Harrison 100+ Steinway pianos
(ad)
Wessell Nickel & Gross
PianoForAll
Who's Online Now
40 members (cygnusdei, clothearednincompo, Ben_NZ, Boboulus, Dfrankjazz, Alfred La Fleur, 12 invisible), 745 guests, and 416 robots.
Key: Admin, Global Mod, Mod
(ad)
Estonia Pianos
Estonia Pianos
Previous Thread
Next Thread
Print Thread
Hop To
Page 1 of 2 1 2
#3128197 06/15/21 08:48 PM
Joined: Apr 2018
Posts: 1,054
1000 Post Club Member
OP Offline
1000 Post Club Member
Joined: Apr 2018
Posts: 1,054
I’m still interested in making my piano hammers lighter (Ed McMorrow, I’m putting all my money on you). What contributes most to a hammer’s weight? Is it the type of felt, i.e. some companies use a heavier, denser felt than others? Or is it mostly the mouldings? Tails? Shanks?

My guess is the felt is the single largest source of weight. If so, does removing 1/16 inch or so of felt all around do much? This seems like something that can be done uniformly during hammer shaping, à la Chris Brown’s hammer shaping jig. Or is removing that outer layer of felt a bad idea? Chris seems to remove quite a bit on his hammer filing video.

I’m not as inclined to drastically reshape the tails or cut down the width of my hammers, as they seem to be the width that they are to span all the tri-chord strings. I also don’t want tails that get pointy and cut into the backchecks.

Anybody tried Keith Akins’ “drill a hole sideways through the moulding” technique? I could easily try it on the drill press while I have the hammers out for shaping anyway.

TIA for all ideas/corrections/admonitions.


Daily driver: Yamaha Avantgrand N1
First crush: Kawai GL10, MP11SE
Current fling: Petrof III
Foster child: 1927 Kurtzmann upright
(ad)
Piano & Music Accessories
piano accessories music gifts tuning and moving equipment
Joined: Feb 2002
Posts: 1,550
1000 Post Club Member
Offline
1000 Post Club Member
Joined: Feb 2002
Posts: 1,550
It depends on the hammers! It can be the felt is VERY thick, it can be the molding material and thickness, and it can be the staple adding a little mass. Your GL-10 has all of these factors together.

Usually to make the hammers light you taper the hammer sides from the tip down to the tail, and also remove excess wood from the molding both above and below the hammer shank.

But this is not a job that should be done on your own piano. It needs to be done by a technician with the skills to do it well. Also, if one does a lot of lightening of the hammers the action will need to be modified to go with it. Sometimes the action ratio needs to be adjusted to provide more speed / inertia striking the strings (to make up for lower mass driving the strings), and of course the key weighting should be changed.

You know, Ed McMorrow's shop is in the Seattle area, you could hire him to modify your piano if you really want to do that. But keep in mind the effect this could have on warranty coverage should the action have any problems - the technician doing the modifications needs to take responsibility for the action from there on.


Don Mannino, MPA
Kawai America
Joined: Sep 2018
Posts: 1,271
1000 Post Club Member
Offline
1000 Post Club Member
Joined: Sep 2018
Posts: 1,271
HI Emery,
I had this very discussion with Chip at Renner the other day. I was ordering a set of hammers for a Baldwin SD-6. My client wants the Blue points. The blue points come in 3 different weights. Chip sent me a photo of a one hammer on the other which had a 2 gram difference. They were the same size. The weight difference came from the felt density. I decided to go with the heavier hammer because this is a 9 footer and the mass is desired.
Now here is the conundrum- I like light actions. I ran the action geometry through the fandrich rhodes action calculator, set up my Grand action model and discovered that the hammer was originally set too far on the shank. After the action ratio was fixed the action is now very responsive. I also was able to remove two lead weight from each key( it had 5 in the bass). Darrell Fandrich said 3 in the bass should be sufficient. Hammer weight is just one part of the equation, its really about balance, since the action is really just a lever.


I have played on the ED McMorrow Light Hammer action before and did not like it. You should go try it for yourself as well. Its a heavy modification, and is costly to undo, so it is best to try it before you buy it(or buy into it).
As i have stated above, such heavy modifications are unnecessary because one can see many fantastic pianists playing Steinways, Baldwins and many other brands with standard actions and seem to do just fine.

Like this one on a Baldwin:


Chernobieff Piano Restorations
"Where Tone is Key"
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
Youtube https://tinyurl.com/5aw83b73


Joined: Dec 2012
Posts: 6,013
E
6000 Post Club Member
Offline
6000 Post Club Member
E
Joined: Dec 2012
Posts: 6,013
I think it a very wise and low cost investment to come to my shop to play some of my pianos to see how you like them.


In a seemingly infinite universe-infinite human creativity is-seemingly possible.
According to NASA, 93% of the earth like planets possible in the known universe have yet to be formed.
Contact: toneman1@me.com
Joined: Apr 2018
Posts: 1,054
1000 Post Club Member
OP Offline
1000 Post Club Member
Joined: Apr 2018
Posts: 1,054
Originally Posted by Chernobieff Piano
HI Emery,
I had this very discussion with Chip at Renner the other day. I was ordering a set of hammers for a Baldwin SD-6. My client wants the Blue points. The blue points come in 3 different weights. Chip sent me a photo of a one hammer on the other which had a 2 gram difference. They were the same size. The weight difference came from the felt density. I decided to go with the heavier hammer because this is a 9 footer and the mass is desired.
Now here is the conundrum- I like light actions. I ran the action geometry through the fandrich rhodes action calculator, set up my Grand action model and discovered that the hammer was originally set too far on the shank. After the action ratio was fixed the action is now very responsive. I also was able to remove two lead weight from each key( it had 5 in the bass). Darrell Fandrich said 3 in the bass should be sufficient. Hammer weight is just one part of the equation, its really about balance, since the action is really just a lever.

Hi Chris. Didn't you release a YouTube video about the Baldwin recently? Don't know if you saw my question in the comments, but I was wondering how you moved the hammer on the shank while keeping the proper strike point.


Daily driver: Yamaha Avantgrand N1
First crush: Kawai GL10, MP11SE
Current fling: Petrof III
Foster child: 1927 Kurtzmann upright
Joined: Apr 2018
Posts: 1,054
1000 Post Club Member
OP Offline
1000 Post Club Member
Joined: Apr 2018
Posts: 1,054
Originally Posted by KawaiDon
It depends on the hammers! It can be the felt is VERY thick, it can be the molding material and thickness, and it can be the staple adding a little mass. Your GL-10 has all of these factors together.

Usually to make the hammers light you taper the hammer sides from the tip down to the tail, and also remove excess wood from the molding both above and below the hammer shank.

But this is not a job that should be done on your own piano. It needs to be done by a technician with the skills to do it well. Also, if one does a lot of lightening of the hammers the action will need to be modified to go with it. Sometimes the action ratio needs to be adjusted to provide more speed / inertia striking the strings (to make up for lower mass driving the strings), and of course the key weighting should be changed.

You know, Ed McMorrow's shop is in the Seattle area, you could hire him to modify your piano if you really want to do that. But keep in mind the effect this could have on warranty coverage should the action have any problems - the technician doing the modifications needs to take responsibility for the action from there on.

Thanks Don. Visiting Ed's shop is on my bucket list. I'm actually thinking of the action on my Petrof. It feels pretty good so far, and I'm thinking about removing the Touchrail because I want to see if that makes the action feel a little snappier due to the faster return. However, that will cause the inertia to go back to how it was. Shaving felt off the hammers in a uniform manner as Chris Brown does would be a more idiot-proof way of reducing hammer weight a little without getting into the major surgery I'd need a guy like Ed McMorrow for. I'm looking for small, incremental changes that don't involve anything drastic. Drilling a hole in the molding is another such small change that may get me there. About 1/2 to 1 gram off each hammer is what I'm shooting for.


Daily driver: Yamaha Avantgrand N1
First crush: Kawai GL10, MP11SE
Current fling: Petrof III
Foster child: 1927 Kurtzmann upright
Joined: Jun 2003
Posts: 29,994
B
BDB Offline
Yikes! 10000 Post Club Member
Offline
Yikes! 10000 Post Club Member
B
Joined: Jun 2003
Posts: 29,994
1/2 gram is a lot on a hammer that might weigh as little as 3 grams.


Semipro Tech
Joined: Jul 2014
Posts: 969
W
500 Post Club Member
Offline
500 Post Club Member
W
Joined: Jul 2014
Posts: 969
Removing the staple will take off about half a gram, and a full side taper done on a table saw with a custom jig should get you where you want to go hammer weight wise. The cut can begin just below the top of the hammer and preserve the width of the hammer there. Pictures of the GL-10 hammers show no taper down the length, so tapering the hammer down to 8 or 9 mm. of width there will result in a removal of a gram or close to it, as you are removing progressively more material from the felt and the molding from top to bottom.

There will be a change in the tone of the hammer when removing this much material, which may be to your liking (or not). You may well pick up more sustain in the treble with the lighter hammer.

It would be prudent for you to consider Don Mannino's advisement on your warranty before making changes. You paid for that warranty when you purchased your piano.


When modifying an action by reducing hammer weight, many rebuilders first choose a lighter hammer, and then process it to achieve desired strikeweights. This is also considered in their choice of action parts and their effect on leverage ratios. Finally, the key leading is appropriately modified.


fine grand piano custom rebuilding, piano technician and tuner
Joined: Jun 2003
Posts: 29,994
B
BDB Offline
Yikes! 10000 Post Club Member
Offline
Yikes! 10000 Post Club Member
B
Joined: Jun 2003
Posts: 29,994
When I weighed a staple, it was about 0.1 gram.


Semipro Tech
Joined: Apr 2018
Posts: 1,054
1000 Post Club Member
OP Offline
1000 Post Club Member
Joined: Apr 2018
Posts: 1,054
Thanks BDB. So maybe 1/4 gram is all I need to remove.

William and Don: I'm doing this to my 99 Petrof that is no longer under warranty period, FYI. The GL10 is safe (for now). Also, I tried removing the staples from old hammers once. First, the staples were harder than !#@$ to remove, and really tore up that section of the felt. Also, some of the shoulders started separating after the staples were gone. Is removing staples really a good idea?

Finally, here's a general question for everyone on hammer weight: Ed has mentioned many times that pianos of yore had lighter hammers, and ostensibly that was a good thing for tone, touch, and durability. Others have mentioned that if hammers are too light, tone will suffer due to insufficient force to properly move the strings. As with all things, there are outer limits, and I trust no one is suggesting one extreme or the other. However, is there agreement that modern hammers are in general too heavy? Would a 10 to 15% reduction in hammer weight ever be a bad thing in modern hammers?

Last edited by Emery Wang; 06/16/21 12:49 PM.

Daily driver: Yamaha Avantgrand N1
First crush: Kawai GL10, MP11SE
Current fling: Petrof III
Foster child: 1927 Kurtzmann upright
Joined: Jun 2003
Posts: 29,994
B
BDB Offline
Yikes! 10000 Post Club Member
Offline
Yikes! 10000 Post Club Member
B
Joined: Jun 2003
Posts: 29,994
You really do not need to remove any mass. What you need to do is play the piano enough that things loosen up on it and your fingers strengthen.

I just worked on an old action that had a significant amount of liquid damage. The piano, a Kurtzmann, by the way, was not valuable enough to justify putting a lot of money into it, but I had to replace some knuckles and a couple of hammers that were previously replaced poorly. There were other hammers that came unglued on one side, but the tops of them were okay, and they were held in place by the staples. The ones that had been replaced were at the top where there were no staples.

I am still not convinced that hammers were especially lighter years ago. If they are lighter, it could be from wear and drying. Old Mason & Hamlin used hammers which were huge compared to those they used later. The top hammers tend to have thicker cores than old hammers, but they do not break as often these days.


Semipro Tech
Joined: Sep 2004
Posts: 2,125
R
2000 Post Club Member
Offline
2000 Post Club Member
R
Joined: Sep 2004
Posts: 2,125
The moment of inertia in a piano is approximately proportional to the square of the action ratio and linearly proportional to the hammer mass. There are other parts of the piano action that contribute to moment of inertia, but the action ratio causes the hammer to be by far the largest contributor.

Joined: Apr 2015
Posts: 314
A
Full Member
Offline
Full Member
A
Joined: Apr 2015
Posts: 314
Originally Posted by Roy123
The moment of inertia in a piano is approximately proportional to the square of the action ratio and linearly proportional to the hammer mass. There are other parts of the piano action that contribute to moment of inertia, but the action ratio causes the hammer to be by far the largest contributor.

It's true but that doesn't always exactly describe "perceived heaviness", for example (ignoring letoff and aftertouch for simplicity):

8g hammer, 5x action ratio, 50mm blow distance, 10mm keydip (8*5^2=200)
should feel the same as:
12.5g hammer, 4x action ratio, 50mm blow distance, 12.5mm keydip (12.5*4^2=200)

but it obviously won't, resistance to acceleration will be the same (from finger perspective) but keydip is larger in second case so time of keystroke will be larger, for this reason I like to use blow distance squared instead of action ratio squared to estimate "preceived heaviness"

Last edited by ambrozy; 06/16/21 08:52 PM.
Joined: Apr 2018
Posts: 1,054
1000 Post Club Member
OP Offline
1000 Post Club Member
Joined: Apr 2018
Posts: 1,054
Originally Posted by ambrozy
Originally Posted by Roy123
The moment of inertia in a piano is approximately proportional to the square of the action ratio and linearly proportional to the hammer mass. There are other parts of the piano action that contribute to moment of inertia, but the action ratio causes the hammer to be by far the largest contributor.

It's true but that doesn't always exactly describe "perceived heaviness", for example (ignoring letoff and aftertouch for simplicity):

8g hammer, 5x action ratio, 50mm blow distance, 10mm keydip (8*5^2=200)
should feel the same as:
12.5g hammer, 4x action ratio, 50mm blow distance, 12.5mm keydip (12.5*4^2=200)

but it obviously won't, resistance to acceleration will be the same (from finger perspective) but keydip is larger in second case so time of keystroke will be larger, for this reason I like to use blow distance squared instead of action ratio squared to estimate "preceived heaviness"

See, this is why I opt for simply filing hammers to see what happens rather than hurting my brain with all this techy stuff.

Just kidding. Keep it coming.

My brain hurts, but only a little.

Last edited by Emery Wang; 06/16/21 09:26 PM.

Daily driver: Yamaha Avantgrand N1
First crush: Kawai GL10, MP11SE
Current fling: Petrof III
Foster child: 1927 Kurtzmann upright
Joined: Sep 2018
Posts: 1,271
1000 Post Club Member
Offline
1000 Post Club Member
Joined: Sep 2018
Posts: 1,271
How appropriate it is that the Wizard of Oz was quoted.

The inertia problem has been solved by Fandrich and Rhodes. And i think thats what all of this comes down to. I have my favorite inertia touch and can manipulated any action to get that touch, or one the customer likes. Actions aren't always put together correctly, the hammer distance can be off, the action spread can be off, the key leads can be out of balance with the hammer. I'm not too sure that hammer mass is as important as techs claim. I have used the exact set of Ronsen hammers for two decades on every size piano there is and they sound great on all of them.

The strike point in my case of the SD6 was off and had to be set back to the correct point.
-chris


Chernobieff Piano Restorations
"Where Tone is Key"
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
Youtube https://tinyurl.com/5aw83b73


Joined: Jun 2003
Posts: 29,994
B
BDB Offline
Yikes! 10000 Post Club Member
Offline
Yikes! 10000 Post Club Member
B
Joined: Jun 2003
Posts: 29,994
The solution to the inertia problem is anti-gravity.


Semipro Tech
Joined: Nov 2010
Posts: 606
P
500 Post Club Member
Offline
500 Post Club Member
P
Joined: Nov 2010
Posts: 606
Originally Posted by BDB
The solution to the inertia problem is anti-gravity.

This is fundamentally incorrect. The only way to eliminate inertia is to eliminate mass. Gravity has nothing to do with it (though mass does create a gravitational field too).

Joined: Feb 2017
Posts: 4,360
P
4000 Post Club Member
Offline
4000 Post Club Member
P
Joined: Feb 2017
Posts: 4,360
Emery,

If there is any wear whatsoever on your Petrof hammers the very first thing you should do is to reshape them REALLY well and consistently (then if course try it to see what that to did). Then you need to do a strike weight analysis (Stanwood protocol). You also need to find out what level of friction you have going on in the shank centers. ALL of this has a cumulative bearing on your strike envelope. If you don't have this data you are essentially walking in the dark. With it, you can decide how, where, and how much you want to remove from each hammer.

Peter Grey Piano Doctor


Peter W. Grey, RPT
New Hampshire Seacoast
www.seacoastpianodoctor.com
pianodoctor57@gmail.com
https://www.youtube.com/watch?v=PK0T7_I_nV8
Joined: Apr 2018
Posts: 1,054
1000 Post Club Member
OP Offline
1000 Post Club Member
Joined: Apr 2018
Posts: 1,054
Assume a modern piano with stock hammers in decent regulation and no major friction issues, and you could wave a magic wand and reduce hammer weight 10% across the board, would you do it?


Daily driver: Yamaha Avantgrand N1
First crush: Kawai GL10, MP11SE
Current fling: Petrof III
Foster child: 1927 Kurtzmann upright
Joined: Jul 2014
Posts: 969
W
500 Post Club Member
Offline
500 Post Club Member
W
Joined: Jul 2014
Posts: 969
Emery, the answer to your question begins with analyzing what you already have by measuring your strike weights, as Peter has suggested. I suggest check the strikeweights of all the C's, that will give you an idea of how heavy your hammers are. Take down and up weights on your samples, and establish the friction level for your notes How many leads are there in each of these notes.

From looking at pictures of Petrof III hammers, it looks like there is no side taper.


fine grand piano custom rebuilding, piano technician and tuner
Page 1 of 2 1 2

Moderated by  Piano World 

Link Copied to Clipboard
(ad)
Pianoteq
Steinway Spiro Layering
(ad)
PianoDisc

PianoDisc
(ad)
Piano Life Saver - Dampp Chaser
Dampp Chaser Piano Life Saver
(ad)
Mason & Hamlin Pianos
New Topics - Multiple Forums
Sustain Pedal Use
by john fh - 09/25/21 02:13 AM
Insulted a Kawai salesman with straight talk
by Cristofori - 09/25/21 01:37 AM
Berg Sieben Früher Lieder and more
by MinscAndBoo - 09/24/21 08:47 PM
Free Books
by Larry Fine - 09/24/21 07:18 PM
Need help finding a piece (Streabbog?)
by cygnusdei - 09/24/21 06:51 PM
Download Sheet Music
Virtual Sheet Music - Classical Sheet Music Downloads
What's Hot!!
My first professionally recorded piece
---------------------
Our Free Newsletter for Piano Lovers!
The summer edition of our free newsletter
---------------------
Visit Maine, Meet Mr. Piano World
---------------------
Posting Pictures on the Forums
-------------------
Forums RULES & HELP
-------------------
ADVERTISE on Piano World
Forum Statistics
Forums42
Topics209,282
Posts3,134,985
Members102,816
Most Online15,252
Mar 21st, 2010
Please Support Our Advertisers

Faust Harrison 100+ Steinways

Dampp Chaser Piano Life Saver

 Best of Piano Buyer

PianoTeq Bechstein
Visit our online store for gifts for music lovers

Virtual Sheet Music - Classical Sheet Music Downloads



 
Help keep the forums up and running with a donation, any amount is appreciated!
Or by becoming a Subscribing member! Thank-you.
Donate   Subscribe
 
Our Piano Related Classified Ads
| Dealers | Tuners | Lessons | Movers | Restorations | Pianos For Sale | Sell Your Piano |

Advertise on Piano World
| Subscribe | Piano World | PianoSupplies.com | Advertise on Piano World |
| |Contact | Privacy | Legal | About Us | Site Map | Free Newsletter | MapleStreetMusicShop.com - Our store in Cornish Maine


© copyright 1997 - 2021 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission
Powered by UBB.threads™ PHP Forum Software 7.7.5