1890s WNG Action Geometry

[Farrell]

If the capstan is too low then cut a short dowel  (the width or less of the key) of the right diameter to approximate the desired height of the capstan.  Lay some double stick tape on the key stick where the capstan will go so that you can roll the dowel back and forth and it will stay put.  



Yup, similar to what David Ilvedson suggested.



Then position the dowel where you think it should go on a key with known front weight (say 80 - 85% of maximum for that note) and your likely strike weight given the hammer set you are using.  Move the dowel/capstan around until you achieve the balance weight you want.  Then mark and measure the position using Stanwood KR system.  With the little stand it's more important that you position it consistently.  I line up the front of the key with the edge of the 90 degree holder which puts the little roller just behind the front-about where your finger is likely to be.  To mark the capstan position for drilling I use a jiffy lead trimmed to 10 grams with the screw hole centered.  Lay the lead on the key surface and move it slowly in one direction in very small increments until the scale just turns over to the number you are targeting.  You will notice that the lead will move a fair distance without the scale changing so you want to be sure you are at the point where the number just turns to insure accuracy between keys.  



Okay, sounds slick. I'll try that. The scale changing thing is one reason I spent the few extra bucks and got one that accurately measures to a hundreth of a gram. It's a bit unsteady at that accuracy (turning off the shop fan helps), but it helps to make clear whether you've got 26.1g or 26.9g on the scale. 



Take a thin transfer punch and insert it down through the hole in the jiffy lead to mark your capstan drilling position.  Mark the beginning and end key of each section and then scribe a line with a razor blade.  Check to see that your lines are contiguous.  Double check and then check it again.  Plugging and redrilling after plugging and redrilling is really a drag.   



Assuming that you are using a 17 mm knuckle I would guess that a Stanwood KR of about .51 or .52 would be about right especially considering the capstan is moving away from the wippen flange which will also contribute to a lower overall ratio.  At least that's where I would start.  It is very likely that .48 KR will be too low.  On a Steinway that KR would normally match up with a 16 mm knuckle. 

David Love



I've got a set of 16mm knuckles - which I think were the original dimension (not that that should mean much). In the past when I reported a very high KR (like 6.0) you recommended a 17mm knuckle. I'll see where I get with the 16mm, but keep in mind that I can always go to a 17mm if I need to.



Thank you very much for your input.



Terry Farrell
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