[CAUT] Lowell gauge zero bearing

[Ron Nossaman]

Bob Hull wrote:
> I'm still working on this Baldwin S-10 and have a question
> about setting the string ht. on the accujust pins according
> to the chart and instructions that were given recently by
> Ron Nossaman including bearing instructions from the
> factory.
> 
> Just wanting to make sure that I'm interpreting the
> instrucitons correctly because the results seem strange.
> 
> To first of all set the bearing to zero we used the lowell
> gauge with the two feet on the bridge adjacent to a string
> and set the bubble to the very middle for ease of reading.

On the bridge? Why? That's where the problem is. You should be 
zeroing from the speaking length direct to the back scale.


> I know the instructions say to start at the top and bring
> 10 strings up to pitch then set them to zero bearing, But
> that will make our heights need to be even lower as it
> loads the bridge fully.  

If you're setting zero bearing, you aren't loading the bridge 
at all, so the soundboard won't be deflecting.


>We didn't change anything in
> regards to plate height, I'm pretty sure.  We mic'd the
> block pretty carefully for thickness.
> 
> Any ideas at why the string hts are coming out so low on
> the hitch pins?
> 
> Thanks.

Yea, you're extending whatever angle the bridge top happens to 
be at relative to the speaking length, into the back scale. 
You want a zero net bearing without taking the bridge top into 
account at all.
Ron N