Harpsichord

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Herz harpsichord

  • 1.  Herz harpsichord

    Registered Piano Technician
    Posted 11-21-2017 20:50
      |   view attached
    Hello All,

    Yesterday I encountered a double manual Herz harpsichord from 1966. This is the first time I have seen one of this vintage. While the instrument is in good shape structurally, the strings are good and the tuning pins are holding well, the jacks are a mess. Those of you with enough experience know what plastic parts from this era will do even if you just touch them. Tongues breaking, plectra falling out and tongue springs breaking. ( Tongue springs as part of the jack moulding? Bad idea!) You got the picture!

    I contacted Hendrik Broekman at Hubbard for advise. Unfortunately he does not have Herz replacement jacks any longer. He does have replacement tongues but I am concerned that when I try to remove the axle pins the jacks will break. I had the idea that it would be possible to somehow affix a piece of steel wire to the jack as a replacement for the broken tongue springs. Hendrik confirmed that is a possibility.

    It is unclear if there was a replacement of jacks somewhere along the line. You can see from the attached picture the back 8' has black jacks. The black jacks have many broken tongues and have a different plectra mortise than the white jacks. Hendrik speculates that Herz was just using up the last of his black jacks although he also speculates that the white jacks could have been replacements too. Note too that there is a register for damper jacks. This is the first time I have seen that outside of Challis instruments. Hendrick said that Herz dropped the damper jack register soon after this instrument was made.

    All in all a tough situation for the owner. My best advice is to send the instrument to Hubbard for a complete jack conversion. Hendrick said it can be done with Hubbard replacement jacks but there will be a good bit modification to make it happen. I cannot take on such a project. I am willing to try to get the front 8' register working as well as possible. Even that is going to be quite a task.

    If there are any similar experiences you can share and how you approached the problem I would be grateful.

    Best,
    Don

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    [Don] [McKechnie,] [RPT]
    [Piano Technician]
    [dmckech@ithaca.edu]
    [Home 607.277.7112]
    ------------------------------


  • 2.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-21-2017 21:41
    Don,
    One possibility is to have new replacement wooden jacks made to match the geometry of the old. http://www.harpsichordjacks.net. That would avoid the need for new bottom guides and possible need for adaptation of top guides. Still a pretty hefty job, and not inexpensive, but doable.

    It is conceivable you could get some Bolton jacks, which would be very close to the right size and geometry. http://boltonjacks.co.uk/orders.html - but there is a notice saying he has had to suspend making them for a year (and I think that notice has been up for quite a while). Might be worth emailing him just to see.
    Regards,
    Fred Sturm
    "When I smell a flower, I don't think about how it was cultivated. I like to listen to music the same way." Mompou









  • 3.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-21-2017 21:54
    If you want to add a metal spring to the jack body, you can probably do that by sawing a kerf in the plastic, drilling a hole in the end of the kerf, bending music wire with a small right angle (which will go in the hole), lay the rest of the wire in the kerf, seal up with a soldering iron. I've done that successfully to add metal springs to tongues where the original plastic spring broke. (Kingstons, where new tongues weren't available). Some very badly focused photos might help make that clear (use your imagination to  provide the focus my camera wasn't up to, many years ago when I took them). The fourth photo is the soldering iron tip heating and spreading plastic over the spring, that is laid in the slot.


    Regards,
    Fred Sturm
    "The true sign of intelligence is not knowledge, but imagination." - Einstein






  • 4.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-21-2017 23:51
      |   view attached
    Hi Fred,

    I did look at the harpsichord jacks site but yes, very expensive and there would be considerable modification to make them work. Too bad about Bolton, the jacks may have worked. Using Hubbard jacks is doable but from Hendrick's description, quite a project.

    Adding a spring to the tongue is a good idea but it would have to be a new tongue. The old tongues would disintegrate if I tried that procedure. Thus the dilemma, risking breaking the jacks to replace a tongue. My thought was to attach the spring to the jack body in a similar fashion as the jacks in my de Blaise. (See attached photo) All in all, it appears any attempts I might undertake to repair are going to be risky with I'm afraid, little reward.

    What tool do you use to remove axle pins? I have had little experience removing them. I did make a tool by setting an appropriate sized pin into a screw that then screws into my WNG center pin removal tool. It worked on a few axle pins I removed from the Challis I restored. Still scary though that a jack could break.

    Best,
    Don

    ------------------------------
    [Don] [McKechnie,] [RPT]
    [Piano Technician]
    [dmckech@ithaca.edu]
    [Home 607.277.7112]
    ------------------------------



  • 5.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-22-2017 11:15
    Glad to see something on CAUT again!





  • 6.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-22-2017 00:54
    Jack dimensions?

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 7.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-22-2017 13:42
    Hi Ed,

    Unfortunately I neglected to write down dimensions before leaving to be on time for my next appointment. The Herz jacks are very slightly deeper and very slightly smaller in width than Hubbard replacements. Of course the Hubbard jacks are offset therefore it would be necessary to redo the lower guide. If the owner calls me back for more work I will measure the jacks.

    Best,
    Don

    ------------------------------
    [Don] [McKechnie,] [RPT]
    [Piano Technician]
    [dmckech@ithaca.edu]
    [Home 607.277.7112]
    ------------------------------



  • 8.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-22-2017 21:36
    These are Hugh Craig jacks, found on eBay. They have a store, and will offer a better price for large orders.
    The jack body is 11 x 4 mm. It is intentionally over length, so you can cut to fit the instrument.
    Here is one I have modified to fit a Sperhake which I strung 1 x 8' with flourocarbon fishing line.
    The jacks were a little loose in the register slots, so I CA glued little leather slips to index them more accurately.
    [In the library]

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 9.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-22-2017 21:54
    I noticed those Hugh Craig jacks when I went browsing for info one what is currently available (alas, less and less each year, it seems). Glad to hear they are somewhat less pricey when ordered direct and in quantity - the prices listed on eBay are exorbitant for everything they offer. Jacks at $10 each plus shipping, a pound of music wire for $250, that sort of thing. But it's nice to know they are available, one more option.

    For getting rid of slop between jacks and registers, I generally stick a strip or two of self-adhesive label style material on the face of the jack where it bears on the register. A little less work than going the leather on the register route, but only really works for a small gap. I wouldn't want to go more than two strips. I have done it quite a bit, and it seems to hold up over at least several years.

    For removing tongue pins, I haven't had to do that too much (haven't run across that many with that design where I actually needed to remove one), but I have tried center pin tool by preference, and it that didn't work, hammered it out with a thin punch. If the jack body is brittle, it doesn't really matter what you do, it will be a risk. You have to use a side of the jack as a bearing surface.

    For adding a spring, one option is to drill two holes through the face of the jack. Bend a piece of music wire to the shape and size of spring, with a right angle. Press the non-spring end through one hole, pull taut, bend the end around and press it through the other hole. Possibly make a small retaining bend, and cut the waste length. I think this should work reliably, as long as you make that right angle bend nice and crisp, and the holes are pretty close to the size of the wire. A set of #61-80 wire gauge drill bits is great for this kind of thing.
    Regards,
    Fred Sturm
    "A mind is not a vessel to be filled, but a fire to be kindled." Plutarch






  • 10.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-23-2017 08:48
    Thanks Ed, They are are possibility but pricey.

    ------------------------------
    [Don] [McKechnie,] [RPT]
    [Piano Technician]
    [dmckech@ithaca.edu]
    [Home 607.277.7112]
    ------------------------------



  • 11.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-23-2017 09:06
    Fred,

    I have seen your method of applying material to take up the slop in the register but have not had the opportunity to try it. If the Hugh Craig jacks were used on this Herz it might be necessary for the 11mm dimension. As I mentioned to Ed, the width was very slightly over my sample Hubbard jack. Certainly less than 11mm. The Hubbard jack is 10mm wide. The registers are thin metal on this Herz so placing material on the jack would be necessary to take up the slop.

    The jacks on my de Blaise have an elegant style for mounting the spring. (see the picture I posted earlier)  I had to replace the springs on a couple of jacks but it worked out well. Of course I did not have to drill the holes!

    Best,
    Don

    ------------------------------
    [Don] [McKechnie,] [RPT]
    [Piano Technician]
    [dmckech@ithaca.edu]
    [Home 607.277.7112]
    ------------------------------



  • 12.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-23-2017 16:13
    Don-
    Hendrick Broekman at Hubbard is probably the person who knows what to do.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 13.  RE: Herz harpsichord

    Registered Piano Technician
    Posted 11-24-2017 08:22
    Ed, I did receive good information from Hendrick and his best advise is to convert to Hubbard jacks and replace the lower guide to accommodate the new jacks. As part of the process he suggested eliminating the row of damper jacks. It is a big job and I would prefer that the customer send the harpsichord to Hubbard for the work.

    ------------------------------
    [Don] [McKechnie,] [RPT]
    [Piano Technician]
    [dmckech@ithaca.edu]
    [Home 607.277.7112]
    ------------------------------