Re: [Harp-L] Reed Chamfering

[Vern <jevern@xxxxxxx>]

Thanks for the pictures and descriptions for chamfering.   Knowing that it speeds up the reed response is very interesting.

Does chamfering make the reed begin to speak at a lower pressure?  i.e. does it facilitate soft playing?

Is chamfering effective near the rivet where there is little air flow?

Do you agree that the major effect may have been the force on the reed when it was on the far side of the plate? Was chamfering equally effective on short reeds that don't exit the far side of the plate?

I imagine that the number of milliseconds to reach steady-state amplitude must vary with pitch.  However, the number of cycles might be fairly consistent.  How many cycles did it take the chamfered and un-chamfered reeds to reach steady state?  If you only have the information for one or a few reeds, what were the pitches and times?

Is this less time than that required for a player to raise or reverse the pressure in his mouth? i.e. does it place any limitation on playing speed.

How did he suddenly turn on the vacuum?  The time required for a switched-on pump to reach full vacuum would be longer than reed response time.  Did he have a quick-acting valve to turn on the vacuum such as a windsaver-shaped pad jerked away from the plate by a solenoid? 

Vern
 
On Dec 31, 2012, at 1:35 PM, Rick Epping wrote:

> Hi folks,
> 
> The page on chamfering I posted a link to the other day was set up for
> viewing by invitation only.  Sorry about that!  It's now available for open
> viewing.  Here's the link again:
> https://docs.google.com/document/d/1hHeMSL1Pt3MV2U9HWGoPBCYicfukRP6W09CpfVssinU/edit
> 
> I have expanded a bit on the article, including an account of tests that
> were made of the process at the Hohner factory, as well as a mention of
> David Payne's interesting test of chamfering a reed slot without narrowing
> the reed-to-slot clearance.
> 
> Best regards and a Happy New Year!
> Rick