> Hi Gene > > Thanks. I think I understand what you are saying now. You use the > sideways spaceing to fudge the placement of the bridge pin sets upwards > (or downwards) on the long bridge to facilitate your spec'd speaking > length. Then you adjust front / back pin distance as needed to avoid any > interference between neighboring sets.. yes? Yes This is why you raised the > point about hitch pin placement as well I suppose... because if that isnt > a given you get further degrees of freedom I suppose ? In relation to Ron and Frank using spread sheet - yes. My problem was the verticle hitch pins that I installed, (a conversion) their larger than original diameter and possible errors in alignment are potential problems with unison spacing and string angles. > > Two questions also come to mind from the discussion... Ron O mentioned a > spread sheet capable of figuring all this out. That of course immediately > caused my left temple to itch a bit... Wouldnt that require the length > the center line of the bridge has to the front termination and the overall > length of the bridge itself ? Along with maximum / minimum sideways > spacing possibilities I suppose I can see a dim tunnel of light here. I am not certain if the spread sheet is used for more than varing the bridge pin offset. Again, the question of building a new bridge or fixing an existing one comes to mind. Aslo.. how within how many mm does one expect to be > able to actually conform perfectly to a spec'd speaking length at > different parts of the scale ? I suppose that if a new bridge is part of the work it could be a very close tolerence. On my piano the bridge is in the original position with new cap - by my observations of the original cap it appears that I can get the scale speaking lengths exact down to note 58 - beyond that the shape of the bridge will not allow these adjustments. However, I have no idea if it will all work out this way - after I do the initial layout I will find out. My desire is not to compromise the speaking lengths. > > One other thing... I hear of three row spacings of 16, 18 mm, 20 mm. > The only premade tool I've seen as a punch for this was from Jahn and came > at 15 mm. Where do you get these or are they something you just make > yourself ? I am busy trying to make my own from clear plexiglass using Ron Nossman's data. I have seen them used in a local rebuilding shop but making them accurately is a bit of a task. I get the feeling that making one for each of these lengths as well as 3 or 4 bridge pin sizes and several wire diameters will be a good investment of my time. Some of the spacing on the original bridge are 24mm but my intent is not to exceed 20mm. Gene > > Cheers > RicB > > > > > Being far from the expert here... I just wanted to throw in a > couple > > bits.... first is your question leaves me a bit confused as > to what you > > are actually asking. If you change your front pin positions > for reasons > > like avoiding interference between neighboring bridge pin > sets... how can > > you avoid not altering the scale ? Speaking length changes > yes... perhaps > > this is not what you were saying... ? > > > My intent is to correct the original scale to as close to my ideal > scale as > possible. I can accomplish this by altering the original bridge pin > spacing > to get the fudge room to change the speaking length. I am hopeful > that there > are no conflicts with front bridge pins as part of this layout work > - I will > not know about this until I put the plate back in and start looking > at how > everything fits the new cap. On the original bridge there was quite > a bit of > variation of speaking lengths and I can correct this from note 58 to > 88 by > changing the original bridge pin spacing. So my priority will be > speaking > lengths and any variation will be due to conflict with neighboring > bridge > pins. Any notes lower than 58 will not conform to my ideal scale no > matter > how I alter bridge pin spacing. > Gene > > >
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