Pianotech

  • 1.  Steinway angeled capstans

    Member
    Posted 20 days ago

    I am working on a 1923 Steinway M replacing whippens, hammer shank/flanges and hammers. It has the capstans that are installed at an angle and I am wondering if there is any advantage to replacing them with capstans at a right angle to the key.

    Thank you.



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    Rex Roseman
    Roseman Piano Tuning
    Copley, OH
    330-289-2948
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  • 2.  RE: Steinway angeled capstans

    Registered Piano Technician
    Posted 20 days ago

    Rex -

    It seems that you just posted this, so I'll offer some advice:  the more information you share at the outset, the more efficient and effective will be the response process.  While there are certainly opinions afloat, you would want to be in control of all the other elements of the action design/redesign.  What were the specs of the original?: action ratio? key ratio? How does/did the original action perform?  What parts are you using?  The wippen heel should match the capstan orientation.

    Photos are also helpful.



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    David Skolnik [RPT]
    Hastings-on-Hudson NY
    (917) 589-2625
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  • 3.  RE: Steinway angeled capstans

    Posted 19 days ago
    What is the angle of the capstan? Anything over 8 degrees is useless and possibly counter productive. You don't gain anything on the action ratio distance measurement but you do lose a gram of downweight,
    (Richard Davenport)
    Is the divot on the old wippen even or worn funny? 
    Keith





  • 4.  RE: Steinway angeled capstans

    Registered Piano Technician
    Posted 19 days ago

    Keith - not being argumentative looking for additional clarity:

    • are you suggesting that, if the capstan angle is less than or equal to 8 degrees, it should/can be retained?
    • how would your concern for divot wear translate? 
    • how would the angle of the wippen heel correlate with the key mechanics?
    • lacking the specs I inquired about, it's not clear that there's any "gain" to be sought in the action or key ratio but, to be clear, using the same hole to install a modified (straight) capstan would alter the effective key ratio.

    Still, your question about the existing angle would be a useful additional spec.



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    David Skolnik [RPT]
    Hastings-on-Hudson NY
    (917) 589-2625
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    Original Message


  • 5.  RE: Steinway angeled capstans

    Posted 19 days ago
    Straight capstans in the same hole would mush the key; You would have to plug and redrill.in my opinion.
    It would also change the wippen ratio.
    I wouldn't worry about it unless the old wippen felt had taken a beating from scrubbing or a cut from the edge of the capstan being at the wrong angle.
    If you want to get technical,,,,,
    Get a piece of graph paper. 
    decide on a base line. 
    Measure wippen center pin and plot it. 
    Measure key rotation point and plot it in relation to the wippen pin
    Measure pin to contact point on wippen heel and key to tip of capstan.
    Use you compass to draw the arcs. 
    Does the capstan roll or slide? Starting from one side of the capstan tip and rolling to the other side is possibly desirable.The action ratio changes to the benefit? as the point on the capstan moves,, a few mm's
    The arcs should center on each other at 1/2 key stroke  I would think



    Original Message


  • 6.  RE: Steinway angeled capstans

    Posted 19 days ago
    Richard Davenport,,, He was part of the Renner allstars and I heard his spiel on the angled capstans. He said 8 degrees was the max. You can see the torque would change the effective lift point if you lean too much. 
    The gray area is you measure the action ratio, the distance of lift and it calculates from the tip of the capstan but when you measure with weight the action ratio calculates from where the capstan enters the key. 




    Original Message


  • 7.  RE: Steinway angeled capstans

    Registered Piano Technician
    Posted 19 days ago

    Keith Roberts said:

    "when you measure with weight the action ratio calculates from where the capstan enters the key."

    Are you sure?  I think from the standpoint of ratio, it makes no difference.  Your earlier list of questions makes sense.  If you think of the capstan as a sphere, and discount any flex, the energy from an angled capstan would be the same as one drilled at 90 degrees.  The question, as you addressed earlier, would be the congruence of the arcs... the minimization of sliding, which changes the ratio through the travel. 

    But, as I said before, we're making up a whole lotta stuff... Rex has thus far told us very little.



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    David Skolnik [RPT]
    Hastings-on-Hudson NY
    (917) 589-2625
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    Original Message


  • 8.  RE: Steinway angeled capstans

    Posted 19 days ago

    Rex, Iʼve done two of that era of Steinway action, converting them to WNG CF parts. For both pianos, the primary customer complaint was too much downweight. I used a square to measure down from the angled head and calculate where the new 90 degree capstan should go, marked each key, plugged the old hole, then used a centering punch and drill press to get the capstan exactly at 90 in the right spot. Some keys with added shoes at the balance rail will require a piece of stock underneath the capstan spot to make the key level to the drill press.

    My reasons for doing so were:

    1. WNGʼs anodized aluminum capstans are multiple grams lighter than the original massive S&S brass capstans. Itʼs an easy way to shave downweight.
    2. WNG whippens are designed for a 90 degree interface, so switching to 90 degree capstans just made sense from a maximum efficiency standpoint.

    If you are using angled-heel whips, youʼd obviously need to retain angled capstans.



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    Jonathan Cleghorn, MME
    Iron Range Piano Co.
    Serving Duluth and Northeastern MN
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  • 9.  RE: Steinway angeled capstans

    Member
    Posted 19 days ago
     Jonathon

    Thank you for your reply. That is the kind of real world experience I was looking for someone to share. Your reasons for changing would be mine exactly. I want to switch to the WSG parts, and I think that you have shown that it would be good to change the capstans and put them back at a 90 degree angle, especially because the new parts are designed to work that way.

    Thank you.

    Rex Roseman 



    Original Message


  • 10.  RE: Steinway angeled capstans

    Posted 17 days ago

    Hello Rex,

    Just FYI, We do carry new Abel Wippens with an angled heel ... 

    Brooks LTD 1800-326-2440



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    Melanie Brooks
    Brooks, Ltd. Piano Products LLC
    Uncasville CT
    (860) 848-6605
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