[Harp-L] Re: Importance of Close Reed Tolerances (was Manji welded reeds?)

["Vern Smith" <jevern@xxxxxxx>]

Hi Ken,

I was looking at reed clearance from a total-leakage point 
of view.  As a chromatic-only player, I admit to a vast 
ignorance about overbends and overdraws.  They are all 
button-pushes to me!   I accept that the closer clearances 
are important to advanced diatonic players.

Do you have any idea about the quantitative values of the 
clearances.  Measurements that I have made indicate 
clearances of about .0015" to .0018" are common in 
production harps.  What clearance values provide superior 
overblow/overdraw performances?  As the clearances approach 
zero, what problems appear?

Thank you not only for your corrections & comments but also 
for your lucid explanation.

If you are attending SPAH, would you enlighten me further 
and indulge some more questions over a beer?

Vern


----- Original Message ----- 
From: "Mojo Red" <harplicks@xxxxxxxxx>
To: "Vern Smith" <jevern@xxxxxxx>
Cc: "Harp -l" <harp-l@xxxxxxxxxx>; "Michael Peloquin" 
<peloquinharp@xxxxxxxxxxx>; "Chris Michaleck" 
<groovygypsy@xxxxxxxxx>
Sent: Monday, August 10, 2009 2:38 PM
Subject: Importance of Close Reed Tolerances (was Manji 
welded reeds?)


Hi Vern,

You said something in your Manji post that I disagree with, 
and thought it bore more discussion. You said: "Better 
alignment and closer tolerances are real but marginal 
advantages to the user..."

I think good reed alignment and close tolerances are hugely 
important, and not at all "marginal" to the user, 
particularly if the user happens to use overbends... and 
even more important to an individual whose overbending 
technique is not perfect.

In fact, from my experience (as an imperfect overbender), 
next to proper gapping, good close reed slot tolerance is 
one of the most important advantages of a well set up harp. 
And it is VERY difficult to achieve close reed-to-reed-slot 
tolerances if the reed is not first properly aligned.

As you may already know, the ability to achieve a stable and 
repeatable overblow depends on the player's ability to 
quickly and completely close or choke off the blow reed in 
order to get the overbend to sound on the draw reed. 
Similarly, the ability to achieve a stable and repeatable 
overdraw depends on the player's ability to completely close 
or choke off the draw reed in order to get the overbend to 
sound on the blow reed.

Closer reed-to-reed-slot tolerances, in combination with a 
well gapped reed are the main factors that allow easier 
overbending. A well gapped reed improves overbending 
performance, but adding good close reed slot tolerances 
improves that performance by another factor entirely, 
particularly if the reed's profile has a slight arc that 
allows it to sit a little deeper into the slot.

In addition, close tolerances (IMO) allows for a a faster, 
louder and more responsive harp requiring less effort or 
breath-force from the player.

Now, admittedly, these advantages may be "marginal" to a 
beginning or novice player, but for serious players, I 
believe that close reed tolerances are a main hallmark of a 
great or well set-up harp.

I'm now wondering what other overblow players opinions are 
on this subject. Peloquin? Michaleck? Others? Comments?

Harpin' in Colorado,
--Ken M.

TeraBlu Band on My Space
http://www.myspace.com/terablu



----- Original Message ----
From: Vern Smith <jevern@xxxxxxx>
To: Michael Peloquin <peloquinharp@xxxxxxxxxxx>; Harp -l 
<harp-l@xxxxxxxxxx>
Sent: Monday, August 10, 2009 1:56:39 PM
Subject: Re: [Harp-L] Manji welded reeds?


----- Original Message ----- From: "Michael Peloquin" 
<peloquinharp@xxxxxxxxxxx>
To: "Harp -l" <harp-l@xxxxxxxxxx>
Sent: Monday, August 10, 2009 11:55 AM
Subject: RE: [Harp-L] Manji welded reeds?

> From: tusker23@xxxxxxxxxxx
> I'm a relative newbie to harp-playing and I know it's 
> probably a dumb question, but.......if welded reeds are 
> such a tremendous improvement over rivetted reeds, 
> wouldn't replacing a welded reed with a screw-fastened 
> reed result in a poorer quality harmonica?

Good question.

> If not, then why not use all screw-fastened or bolted 
> reeds in the first place, rather than welded reeds?

Spot-welding is much more amenable to an automated assembly 
process than rivets or screws. (See those videos on assembly 
of automobile bodies.) One suspects that this is the most 
important reason for choosing spot-welding. Better alignment 
and closer tolerances are real but marginal advantages to 
the user...
<Snip>