Pianotech

Expand all | Collapse all

Heavy action. 1927 M&H grand

  • 1.  Heavy action. 1927 M&H grand

    Posted 10-10-2022 18:48
    Working for a customer with a 1927 Mason & Hamlin grand.  "Recently" rebuilt.  Maybe a decade or so.  Used little since then.  Customer complains of heavy touch.  I plan to iron the key bushings and clean and lubricate the key pins.  I noticed that many of the round key leads have either been removed or fallen out at some point.  Most of the white keys are missing at least one.  I've purchased a set of leads, but have no experience with "re-weighting" keys so-to-speak. 

    Assuming that the bushing and key pin work doesn't yield the results he wants, how should I approach the issue of the missing key weights?

    ------------------------------
    Timothy Edwards
    Beckley WV
    (740) 517-7636
    ------------------------------


  • 2.  RE: Heavy action. 1927 M&H grand

    Member
    Posted 10-10-2022 19:06
    There are a number of journal articles on the subject but before doing anything you need to get measure where each key is now with the current leading. You should also be looking at friction in the hammers and check the friction on the rep levers, jacks, whip flanges. Also think about easing the keys and the balance pin holes. I have been working on a 1919 Mason & Hamlin that was unplayable but lots of tlc and lubrication plus PLAYING by many different pianists has greatly improved it. This piano was not stored properly and had some mold issues and humidity induced friction. What model of Mason & Hamlin is it ?   You may want to work with some of your PTG Chapter colleagues like Maggie and Andy

    ------------------------------
    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
    ------------------------------



  • 3.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-10-2022 19:32
    Greetings,
       That really isn't enough info for any of us to offer suggestions.  Yes, if the leads were removed from the keys, the touch will be heavier, but it may have been too light with them in there and new action parts installed.  

       Suggestions will be more pertinent if we know some of the down/up weights, Front weights, and Strike weights, as well as what sort of action ratio you have going.  Friction can play a part, but with. "rebuilt" action, there is a lot of room for mismatched parts.  
    Regards, 





  • 4.  RE: Heavy action. 1927 M&H grand

    Posted 10-11-2022 06:28
    Before going for touchweight issues, make sure piano is well-regulated.
    Things I'd look at before touchweight would be:

    1. Tight hammer flanges.
    2. Tight whippen flanges.
    3. Tight balance rail key holes. Key's should drop on the pins easily.
    4. Tight front rail key bushings. Lift key; it should drop easily.
    5. Dampers lifting too early. Check that dampers don't lift from key before hammer is 1/2 to strings; put finger on damper head to feel for lift.
    6. Hammer knuckles badly worn. If they're flattened this is major friction.
    7. Jack alignment, repetition lever height, letoff, etc.: basic regulation.
    8. Drop is excessive.


    That's a start.  I always go for lubrication/friction and regulation first and work from there; this solves 99% of problems with 'heavy' pianos.

    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 5.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-11-2022 07:26
    And in addition to the above list I would add the fact that the replacement hammers are likely 1-3 grams heavier overall than the originals. THAT often overlooked fact by "rebuilders" is a starting point for several poor followup decisions.  You should anticipate several hours of weight reduction at the hammers. It can make a HUGE difference (at 5:1 ratio).

    Peter Grey Piano Doctor

    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 6.  RE: Heavy action. 1927 M&H grand

    Posted 10-11-2022 19:03
    Peter,

    When you refer to "weight reduction of hammers", may I assume this entails filing them? 
    If so, then would that also require resetting hammer blow, as well as the rest of the action regulation?

    ------------------------------
    Timothy Edwards
    Beckley WV
    (740) 517-7636
    ------------------------------



  • 7.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-12-2022 07:44

     

    Yes, and in addition to the new hammers being heavier they may be mounted on original spec high-ration shanks. Check the center pin to knuckle core distance. 17mm is often necessary to deal with the increased weight of the hammers.

     

    Mark






  • 8.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-12-2022 07:30
    When I first got into key weighting in the 1980s, the conventional wisdom was "don't mess with those key weights. They were put in correctly at the factory." Now we know it's not safe to assume that the factory key leads are necessarily correct. It is however safe to assume that if the action is well regulated and voiced and touch weight is normal and the keys have a normal amount of key leads in them, the action will feel normal. What is normal touch weight? Simply measuring the down weight won't tell you much. Always measure up weight as well. This will immediately reveal whether or not friction is normal. With a normal playing friction, the difference between up and down weight will be close to 24 grams. Once the friction is fixed you can turn your attention to deeper matters.

    You mention that leads are missing. Don't assume that is a good or bad thing. Find out if they are normal by measuring. Take the key out of C4 and tip it onto a digital scale using the front weight protocol. Above 30 grams is excessive. 27grams is more of a medium value. Do a test at C4 by adding or subtracting key leads to make the front weight be 27g. Put the key back in the piano. If your down weights and up weights are still really high this indicates you have a hammer weight that is too high. Try switching to a lighter hammer and shank from higher up in the scale to find one that balances the action normally. If a much lighter hammer is indicated for a normal touch weight then you might be facing hammer weight reduction. That's and advanced special skill set. You'll have to learn how to do that or get help from someone who has those skills. Filing the hammers down isn't advised. Weight can always come off the sides and other places. Another advanced skill option is changing the action ratio to bring the touch weight down. This means altering action geometry, usually by such means as moving the capstan line or modifying the balance rail point. When you are out of your skill depth relax and use the team approach with your piano tech associates to give the best service to your client.   Good luck!

    ------------------------------
    David Stanwood RPT
    Stanwood Piano Innovations Inc.
    West Tisbury MA
    (508) 693-1583
    ------------------------------



  • 9.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-12-2022 07:55
    Yes, full agreement with David.  Generally speaking though, almost any replacement hammers in the last 40 years are found to be heavier (some MUCH heavier) than originally installed. Three areas to give "quick and dirty" weight reduction are:

    1) The coving behind the hammershank. Unless the hammer maker intentionally and purposely carved this out knowing where the bore point would be, there is usually a substantial amount of detrimental wood weight in that area. If nothing else, this should be removed to the max (without compromising tail strength). 

    2) Tapering the sides. I have seen plenty of new and replacement hammers with minimal or no tapering. Up to a gram of material can sometimes be removed in this way. This can be done on a belt sander OR with a hand held grinder. I made a video of doing this but have yet to publish it. 

    3) The wood on the back side of the hammer itself including the shank just above the tail (where it's glued on). Often material can be safely removed here as well.

    Remember that this is a "q&d" method. Refinement requires calibrating the strike weight as per David's protocol. But do his analysis first to confirm.

    Peter Grey Piano Doctor

    ------------------------------
    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 10.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-12-2022 08:49
    Greetings,
        I try to get my SW in place on the tapering jig when hanging new hammers.  After the AR is determined, (by the architecture of the piano, itself), I will begin by using what I know are acceptable FW's to find the SW that gives me the "touch" I want.  "Touch" is a broad subject, ranging from a light-feeling 60 gr DW in a McMorrow action, to a controllable 46 gr. in some older Chickerings, etc.  When tapering from the crown to the tail, I can take 2 grams off most of the larger hammers without sacrificing crown width.  The tails get narrow, but   with a smooth surface and good back-check angle, I didn't notice any excessive wear in heavily used (40 hrs per week in the university practice rooms), pianos.  

        I have found only a little reduction in removal of the wood under a normal cove.  Usually .5 grams or less.  What I have found makes a major difference is thinning the hammer on the sides, sometimes into a subtle "hourglass" shape. Like Peter, I have done this to hammers on the shanks by using a belt sander, but I really try to hit the target on the tapering jig, as it leaves cleaner sides.  If I do use the sander, I take the shanks off the rails, as pinning can really take a hit during the process.   

        On jobs that justify it, I will measure the SW's while mounted on the rail by putting the digital scale on a lift block so that I can just go down the line dropping the hammers, tail first, on the scale. It can also be done upside down by placing the stack on a pair of large blocks and measuring the SW with the nose of the hammer on the scale and the shank parallel.  It helps to have the bench vibrating a slight bit to overcome the static friction in the pinning.  I do this by using some fairly loud music through a speaker I clamp to the bench, ("Living On A Prayer" does a good job of this, as well as most AC/DC tracks). 
    Regards, 





  • 11.  RE: Heavy action. 1927 M&H grand

    Posted 10-12-2022 14:28
    Most of any weight change in a hammer is in removing felt, unless the moldings are massive. An oscillating spindle sander makes reshaping hammers a breeze.

    A cove will only remove around 3 grams, for this reason I order hammers uncoved; it also helps when arcing the tails. I also order the overall length 3mm longer than the longest bore distance (tapered bore) to trim tails to an even length when done (at the final weigh-off). This area is a good place to remove that last little bit of SW, if needed.  Tapering is done prior to hanging.  I made 'hanging squares' when installing the hammer onto the shanks. These either center the tail or offset it for pitched hammers (a set screw accounts for the taper).

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 12.  RE: Heavy action. 1927 M&H grand

    Posted 10-12-2022 18:05
    Thanks, everyone again for the great input!   I think my next visit will be occupied with friction issues (keypins, bushings, action centers) and checking for regulation problems.  The key weight and action weight issues are, I believe more than I want to get into at this point, so I'll probably be calling on Andy or Maggie to assist if we need to go that far. 
    Many thanks for all the expertise here.

    --- Tim

    ------------------------------
    Timothy Edwards
    Beckley WV
    (740) 517-7636
    ------------------------------



  • 13.  RE: Heavy action. 1927 M&H grand

    Posted 10-12-2022 20:14
    Usually correcting damper timing is an improvement. When the felt compresses, the underlevers are lower and add their weight too soon in the keystroke.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 14.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-16-2022 19:28
    Jon,   I'm curious about your "hanging squares" as this kind of hammer trimming for weight remediation is often one of the first things I will try since it pays off so well.  But when rehanging the hammers of course the added full taper makes it even more challenging to get them truly vertical--the angles of the sides are more acute and confusing to the eye and the base of the hammer tail, the one touchstone that's left, has been reduced by another couple mms.
     
    I wonder if you could post a photo of your "hanging square" please.  Sounds like a great idea.

    ------------------------------
    Cecil Snyder RPT
    Torrance CA
    (310) 542-7108
    ------------------------------



  • 15.  RE: Heavy action. 1927 M&H grand

    Posted 10-16-2022 20:27
    It's a simple square cut from wood (a scrap spinet music desk piece). A screw at the base is used to account for the taper. Since I usually full-taper with the tail being 8 mm wide at the bottom, it usually means the screw is protruding 1~1.5 mm for the treble. For the bass and low tenor the screw is backed out 1.5~2 mm to account for the added pitch to insure clearance ( .5 mm difference between bass and treble).

    I am now using WNG s/f and Ronsen hammers. I bore .003" larger than the shank and use a counter sink (in a drill press) to lightly bevel front and back. I dry fit the hammers and then add thin CA glue to the bevels to wick in, two applications.  I had been using GluBoost but I'll try Rhino CA glue next time since they claim to be impact resistant.

    I  order the molding 30 mm longer than the longest bore, making the overall length longer than needed because I trim the tails to 27 mm in length after boring and want a good mount to cut off. This insures an even tail length.

    I also order them un-coved because a cove usually interferes with tail arcing and it only removes about .3 grams, hardly seems worth it. In the final weigh-off, the cove-area is a prime area to remove material, if needed.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 16.  RE: Heavy action. 1927 M&H grand

    Posted 10-17-2022 10:37
    Jon,, you should try the glue WNG sells. I ordered their drill bit and glue. The dry fit is very good and the glue just says Rx,,
    I read how you glue hammers on and I got a little nervous. 
    I just did a set of hammers and as usual, I had a few mess ups. So I plugged them using the tite bond thick, (I like the hardness rating) and re drilled. 

    My method is to put some glue on the shank and with a toothpick, I make sure the glue coats the shank all the way around,, then do the same with the hammer hole using the extra glue from the shank. It takes longer than you think to coat everything evenly. 

    Then I had to pull one of the hammers I plugged. The Rx glue won. The half of plug still in the hammer came out with the shank. Then I had to remove that from the shank. I ended up destroying the shank and getting a replacement. I generally use the Hot Stuff CA glue. The thin is great but for thick, the Rx glue was amazing. You need to try it. Those hammers will not come loose from what I saw. Longevity of CA glue doesn't seem to be an issue but I would bet on the Rx glue WNG sells. 






  • 17.  RE: Heavy action. 1927 M&H grand

    Posted 10-17-2022 12:11
    Coating the shank with glue and spinning the hammer on, as was done with hot hide glue, may be just a hold-over from the 'old' way of doing it. The bits they sell are too large to suit me, so I use my own bits. Since there is not a huge gap to fill with thickened CA, then wicking thin CA should have the same results.
    I can better align the hammers dry before applying CA.

    For WNG shanks, I think a removal tool should be a stepped punch. The center would go in the tube and the outer diameter would press on the walls of the tune.
    You might need different sizes for their different tubes.  I think I prefer the Flex 3, the thinnest shank.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 18.  RE: Heavy action. 1927 M&H grand

    Registered Piano Technician
    Posted 10-17-2022 13:23
    Greetings,
       I have had the best and easiest time of gluing hammers to WNG by drilling for a snug fit, installing the whole set of hammers dry, and then finalizing my traveling and spacing, as well as proving my strike point distance.  Once everything is as I want it, I just wick in the thin CA from the front and back without actually touching the hammers or shanks. After it is set, I cut the protruding shank ends off with a Dremel cutoff saw. 

        I use the thin CA from Stewart-Mcdonald guitar supply, and when I did have to remove a hammer, found that a 30 minute soak with acetone was the only way to get the hammer off without tearing things up. 
    Regards,