Downbearing Error - solution

[Richard Brekne]

Hi John, David and Ron.

This is not a one piece plate and  plate bolts wouldnt work on this 
instrument. I could shim the back plate up but that ends being just 
about as much work as shaving down the bridge a bit. Its a solid bridge 
with no cap except in the top 30 notes.

David and Ron.

If either of you are under the impression that I have any objections to 
the RC&S methods then I dont know what to tell you. My objections get 
into gear strictly when people start making comparisons between methods 
and means that are off topic to begin with and clearly negative in 
character.  I just got into it with one of your counterparts.... you 
might say one of your betters in at least one sense of the word... since 
the fellow is actually running a successful factory in Germany.  He is 
on the opposite side of this RC&S vs CC thing. And his snearing at non 
CC boards was every bit as unproductive and inappropriate as many of the 
comments against CC boards I hear around this place. And, as you can 
probably expect if you really know me at all... I got every bit as 
provoked as I usually do.  It gets tiresome hearing how the other guy 
sucks all the time when all you want is some hard argumentation for why 
this or that or the other thing is what it is. It matters not which side 
its coming from as far as I can see.

Calculating soundboard deflection in this case could not account for the 
error David, since I ended up with more string deflection then I 
figured.  There was a procedural problem here that had to do with a 
difference between the soundboard and bridge being screwed and clamped 
into place and when the assembly was finally glued into the rim. The 
thing ended up higher.

Here... in this question... I just wanted some thoughts as to what went 
wrong with the procedure I actually did use.  And what to do about it.  
Not a lot of need for any controversy here, not a lot of need for 
anything except some friendly professional advice...which is what we are 
supposed to be all about here IWUTI.  And indeed... a few onlookers were 
kind enough to send me some encouraging thoughts off list.

Cheers.  And enjoy your holiday's one and all

Richard Brekne


     > Installing a plate float system is definitely a nice thing to
    have for
     > tweaking bearing after the fact.  Precalculating the bridge height
     > (trigonometry does come in handy sometimes) from a straight
    string stretched
     > between the termination points forward and aft also helps as does
    installing
     > vertical hitches which can also be adjusted.  Calculating the
    soundboard
     > deflection (easier on a rib crowned and supported board) also
    gives more
     > data with which to ensure the bearing comes out close and helps
    to prevent
     > these kind of mishaps.  Of course, they are usually represent
    modifications
     > to the original which provides a psychological challenge to
    some--but not
     > all!   
     >
     > David Love

        It's all very easy to argue against - until you're there.
        Ron N