Re: [Harp-L] Re: Yellow Brass (was GM)

[joe leone <3n037@xxxxxxxxxxx>]

On Mar 9, 2010, at 12:42 PM, John Kerkhoven wrote:

> SB wrote:
> "Rick Epping championed the technique of breaking the right angle  
> at the
> point where the reed joins the rivet pad."
>
> What does "breaking the right angle at the point where the reed  
> joins the
> rivet pad" mean? Over what was this an improvement and why?
>
> John
I had written when I first came onto harp-l (and slidemeister) in  
2000, that this juncture where the reed shaft meets the rivet pad is  
a critical point in reeds. The reeds are made to a set thickness  
FIRST. THEN the mill comes down on the stock while it is still in a  
large strip and cuts down into the shaft portion of the reed stock  
making it thinner from the rivet pad and outwards. (Sometimes the  
mill is lifted to form a weighted reed tip).

I explained yesterday that in machinists parlance breaking an edge  
means to leave NO sharp inside cuts that would cause a strain at that  
point. Outside edges can be broken (or eased/rounded/whatever) too,  
but are not as critical as inside edges. ALL joints need to be  
radiused (no mater how slight the radius). This allows extra 'meat'  
at junctions.

Leaving a sharp step in the rivet boss to reed shaft causes  
vibrations in the reed to transfer sonic waves to the sharp inside  
corner (where the reed is weak). Constant sonics at that point has  
the effect of singing high notes at a shell blown champagne glass, It  
can cause a fracture.

Possibly Rick read my writings? And then again?

smokey joe  (I don ha to cho ju any stinkin badges)