1890s WNG Action Geometry

[Farrell]

Yes, 4.9, Stanwood. Linear measurements suggest 4.8 (man, you're right on target!). I agree with you - I'm too far forward with the capstan. I'll be trying a location that simple mathimatical interpolation would suggest to yield about 5.5/Stanwood.

Let's see - on one note, the original location was R = 6.24/Stanwood and an 8 mm move yields R = 4.92/Stanwood. So if I target R = 5.5/Stanwood I should move the capstan 4.5 mm forward from the original location.

On the other note, the original location was R = 6.24/Stanwood and an 11.5 mm move yields R = 4.64/Stanwood. So if I target R = 5.5/Stanwood I should move the capstan 5.3 mm forward from the original location.

So I guess my next try should be with about a 5 mm move forward from the original location. And of course, the increase in wippen heel height will be smaller as I adjust that to have the heel/capstan interface on the magic line at half-blow.

I'll give that a try on a few notes and fully regulate them - that'll give me something specific to talk about then. Thanks for your (and all others!) input.

Terry Farrell
  ----- Original Message ----- 


  Is that a Stanwood 4.9 ratio?   If so, I think that's a bit low and you might compromise the regulation some.  Remember that as you move the capstan forward on the key you also benefit from the move away from the flange in the 2nd class wippen lever.  I don't like to get a ratio lower than 5.5 (Stanwood) which should allow you a fair amount of leeway with hammers and front weights to achieve something between 36 and 40 BW.  My usual target is 37.  If you calculate the ratio via linear measurements, the number will be bit lower than with Stanwood measurements.  



  Otherwise, capstan movements are pretty common on action I work on.  Relocating or changing the height of wippen heels is not uncommon either.



  David Love
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