Pianotech

  • 1.  Kawai 607 regulation

    Registered Piano Technician
    Posted 07-03-2023 21:08

    I'm about to regulate a Kawai 607. I'm looking over the regulation guide from Kawai for their upright lines below:

    Kawai-Upright-Piano-Regulation-Manual.pdf

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    Kawai-Upright-Piano-Regulation-Manual.pdf


    Do all Kawai upright models use the exact same measurements? It says hammer blow distance is supposed to be 46mm which seems like a lot for a console piano (limited experience on my end perhaps). Of course, I can check all these parameters when I get into it, but I want to be as prepared as possible ahead of time.

     Thanks!



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    Tim Foster
    New Oxford PA
    (470) 231-6074
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  • 2.  RE: Kawai 607 regulation

    Registered Piano Technician
    Posted 07-03-2023 22:44

    I think you can rely on the manual however sometimes you have to take wear into account. 

    Also remember regulation starts at the front of the key, not the back (capstans). If the key height isn't right it will affect all the other adjustments.



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    Steven Rosenthal RPT
    Honolulu HI
    (808) 521-7129
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  • 3.  RE: Kawai 607 regulation

    Posted 07-04-2023 09:31
    I believe Kawai uprights have no lost motion. 
    My memory hasn't served me well lately but I thought that was from a class I took from Don Mannino. 





  • 4.  RE: Kawai 607 regulation

    Registered Piano Technician
    Posted 07-04-2023 10:37

    Start with one key, usually in the center where there's the most wear.  Try the spec's from the manual, and see what result you get.  What usually happens is that the balance rail felt crushes a bit, and the keys sag.  Be sure to adjust the lost motion before regulating the key height because it won't be accurate otherwise.  Japanese pianos are usually very well regulated from the factory, so most often if you just do the capstan adjustment, that will fix it.  I usually test the capstan adjustment by pulling on the hammer rail.  If the hammers follow the rail, just a little, that's good.  If some hammers don't move, the capstans are too high and there's no lost motion.  Initial adjustment I will touch the key and see if the backcheck moves just slightly.  If the hammer and backcheck move simultaneously, there's no lost motion, so back off the capstan until you get it right.  Once you have the lost motion adjusted on a key or two, see how it performs.  If you have bobbling hammers, there's a good chance the key height is too low and there's not enough movement of the key to make the action work properly.  Don't adjust the key height until you have the capstans regulated.  Overall, regulation specs from a manual are just a starting point.  Often you find that the specs don't work, or something has been done by another tech that messed things up and now it doesn't work properly.  But my bet on this is that your Kawai worked very well from the factory, and they keys aren't level anymore because of wear or crushing of the balance rail felt. 

    If you're sanding hammers, be sure to account for the loss of the felt by moving the hammer rail closer to keep the blow distance at spec.  That will also require lost motion adjustment afterwards.  If you have moved the rail up and regulated the capstans, you may find that the dampers are raising too soon.  The action will feel a bit heavier because the spoons will be closer to the damper levers and lift the dampers too early.  So, adjusting the spoons is required.  And before you do any damper adjustment, make sure the dampers all lift evenly with the pedal.  If the dampers are lifting too early, the damper felt might be sinking into the strings, and damper lift from the pedal won't be even anymore.  Adjust the damper wires first to get even lift with the pedal.  Then do any spoon bending as necessary so the dampers begin to move when the hammer and key are about half dip and hammer blow.

    In summary, there are several places that need to be inspected for wear: the hammer (string cuts), the balance rail felt, worn damper felt, and hammer butt leather.  Regulation is usually needed when these are worn, and sometimes replacement is necessary when regulation doesn't fix the problem.

    Good luck.  Let us know how it goes.



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    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
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  • 5.  RE: Kawai 607 regulation

    Registered Piano Technician
    Posted 07-04-2023 10:57

    Paul, thank you very much! The piano is not badly out of regulation, and is one that I bought in preparation for the technical that I'll be taking at the convention in a few weeks. I only have grand pianos at home, so I thought I should get an upright. I got it at a low enough price point, and it is in good enough condition that my goal is to flip it after I'm done with the regulation and some other minor repairs. Overall, I could probably get away with not regulating it, but I wanted some extra practice. There's one regulation that seemed way off, the dampers lift well before the hammer travels halfway to the string. When I play it, the action feels a little heavy, which is why I looked to the dampers in the first place. I am wondering if it somehow came from the factory that way, or if the previous owner wanted a heavier action and had it regulated that way. 

    Thanks again!



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    Tim Foster
    New Oxford PA
    (470) 231-6074
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  • 6.  RE: Kawai 607 regulation

    Registered Piano Technician
    Posted 07-04-2023 11:53

    Hi Tim:

    You might look at any looseness in the action brackets and key bed studs.  I sometimes find that if I pull on the brackets where they sit on the studs, they might wiggle a little bit.  Anyway, it's hard to say why the damper regulation would change so much.  Once I did a lot of regulation on a piano, only to discover that the key bed itself had moved.  If you look underneath at the plate where the keybed is attached, you'll find some wedges screwed on.  On that particular piano, a wedge was missing on one side.  That was after I'd spent more than an hour re-regulating the piano.  It's possible there may be some structural failure, and maybe it got dropped?  Just a wild guess..  In my experience, every time I have to re-regulate a piano I find that there's something that I missed that explains why it's so far off.  I had a call from a guy who had bought an almost new Essex upright.  It had been worked on by a big-wig Stineaway technician.  But it didn't work right at all.  When I asked, the owner said that the tech had taken the keys out and did something in there.  I discovered piles of front rail punchings in the piano.  They key dip was so far off I couldn't believe what I was seeing.  Bottom line is, you never know if somebody messed things up before you got there because they didn't find what was actually wrong.  Somebody might have found too much lost motion before you got it, and regulated it by raising the capstans.  That moved the wippens up, and the spoons moved closer to the damper levers.  Which is why the dampers move too soon.  My guess is that you'll have to adjust the spoons (fun, right??), and all will be well again.  Spoons are a pain to adjust of course.  I usually have to remove the key(s) to get enough room for the tool.  I usually use the "L" shaped tool with the slot in it.  There's another one that looks more like a damper wire tool, shaped like a "U" on the end of a long thin shank.

    Anyway, a bit of detective work will probably show you the problem.  If the cabinet is good and the piano plays well, it should be a pretty good flip.  Kawai's are good pianos. 

    Best,

    Paul



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    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
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  • 7.  RE: Kawai 607 regulation

    Registered Piano Technician
    Posted 07-05-2023 11:39

    Tim,

    That is very observant of you - you are correct, the blow distance is an 'ideal' spec in the design.  In reality, if you measure straight from the hammer tip to the string it is usually 42 - 43mm, if you measure from the tip of the hammer down to the actual strike point on the string, it will be 43-44mm.  Rarely does 46mm work - the hammer shank will be angled back too far if you move the rest rail back to get this spec.

    Do check the key height from the key slip at the start, as others have said.  The nominally 21mm spec is correct, but 20mm - 22mm will work. If the ends are at 20mm, set the center the same.

    As with most upright pianos, you can often shim the balance rail to get the overall key height correct, then fine regulate with punchings.

    If the hammer butts are not worn, Kawai actions perform well with no lost motion at all. In new pianos they are set so that the jack is SLIGHTLY supporting the hammers at rest. Almost negative lost motion. When you pull back on the hammer rail the hammer will not move at all, but also pushing down on the back on the key should not move the hammer either!  This means that, when perfect, both the jack and the hammer rest rail are supporting the hammer at the same time.

    Once you get the key height set in the center, work with middle 'C' to verify if the specs work out. 10mm dip is good, and with the letoff at 3mm and backcheck set at 15mm playing the note mf and holding the key down should result in the jack being clear of the hammer butt skin by a slight amount. If it is, make sure there is a little extra room for the jack to move out farther - pull it with a capstan tool or something to make sure there is another 1mm clearance before it touches the jack stop felt (which is on the letoff rail for this model).  I mention to do this with your first sample note because moving the letoff rail to give some clearance will require resetting the letoff again.

    Happy regulating!



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    Don Mannino RPT
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