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From the Jim Ellis Workshop. What the heck is it?

  • 1.  From the Jim Ellis Workshop. What the heck is it?

    Posted 09-21-2018 09:54
    Any ideas what this thing is?


    qJFTIV8SMigf5erSjELU_ellis jig 004.jpg

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    I don't always play the piano, but when i do, I prefer my own.
    chernobieffpiano.com
    grandpianoman@protonmail.com
    865-986-7720
    ------------------------------


  • 2.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 10:24
    More photos? 
    Why do you have it?

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    David Skolnik [RPT]
    Hastings-on-Hudson NY
    914-231-7565
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  • 3.  RE: From the Jim Ellis Workshop. What the heck is it?

    Posted 09-21-2018 10:27
    Another has it. It could be coming up for sale. That's all the pics available.





  • 4.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 11:34
    Chris,
    I worked with Jim on several piano technology projects.  JIm's day job was an instrumentation engineer, and he was highly skilled in making test and measurement equipment.  

    I have no direct knowledge about the equipment in the picture.  But I suspect it was designed to support and tension a piano string; the pulley on the left end of the device is the clue.  I also guess the larger sliding cylinder would serve as an adjustable termination -- establishing the speaking length of the string.  And on the left (far) end I suspect is a  transducer (electro-magnetic sensor) of some sort.  That transducer would be positioned along the speaking length, and likely was used to observe vibration modes/nodes. 

    As configured, the equipment would *not* be used for analyzing longitudinal modes.  In fact, Jim built a dedicated and massive monochord with specialized transducers to study those LMs.  The result was an article c.2008 in the PTJ.

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    John Rhodes
    Vancouver WA
    360-721-0728
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  • 5.  RE: From the Jim Ellis Workshop. What the heck is it?

    Posted 09-21-2018 11:54
    Oh thank John. Or should I say Oh Great One.





  • 6.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 13:23
    I think I attended a class where Jim showed this contraption.  If I recall he used it to show that a string moves back and forth as well as up and down. I trying to remember the name for this, something like longiston or longisture vibration. In other words the string doesn't just vibrate up and down but also front and back. I can't remember why it's important to know this, but I believe he wrote an article about it in the Journal. Maybe someone with a CD of all the Journals from about 20 years ago can find it.

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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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  • 7.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 13:58
    Either you're trying to say 'longitudinal' or something else I've never heard of.   I'm on phone now so can't check until I'm home.  You may also be confusing a different phenomenon that Robbin Hufford (sp?) Wrote about during the 'does the string make bridge go up and down' wars.  I'll try to find that email as well.

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    David Skolnik [RPT]
    Hastings-on-Hudson NY
    914-231-7565
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  • 8.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 14:45
    longitudinal'

    Yeah, that's the word.

    Thanks, David


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    Willem "Wim" Blees, RPT
    Mililani, HI 96789
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  • 9.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 14:24
    Jim did a lot of work on inharmonicity and longitudinal harmonics. I'd guess it was a device to test strings at varying lengths and tensions. 

    ddf

    --
    Delwin D Fandrich
    Fandrich Piano Company, Inc.
    Piano Design and Manufacturing Consulting Services -- Worldwide
    6939 Foothill Ct SW -- Olympia, WA 98512 -- USA
    Phone 360.515.0119 -- Mobile 360.388.6525





  • 10.  RE: From the Jim Ellis Workshop. What the heck is it?

    Posted 09-21-2018 16:03
    It looks like the article was in 1998. In the reference it mentions Mr Ellis had applied a patent .
    Here was a diagram from the article. It's above my head, so if anyone is interested in Mr' Ellis' equipment, let me know i'll pass your contact info to the owner.
    -chris


    ------------------------------
    I don't always play the piano, but when i do, I prefer my own.
    chernobieffpiano.com
    grandpianoman@protonmail.com
    865-986-7720
    ------------------------------



  • 11.  RE: From the Jim Ellis Workshop. What the heck is it?

    Registered Piano Technician
    Posted 09-21-2018 19:27
    Ed McMorrow comes to mind. 

    ddf

    --
    Delwin D Fandrich
    Fandrich Piano Company, Inc.
    Piano Design and Manufacturing Consulting Services -- Worldwide
    6939 Foothill Ct SW -- Olympia, WA 98512 -- USA
    Phone 360.515.0119 -- Mobile 360.388.6525