Re: CX 12 spring mods [was tight slide action]

["Scorcher" <scorcher@xxxxxxx>]

Michelle relates the details of a "recommended" modification to the Spring
Retainer of a CX-12.
The modification, detailed here:
http://www.angelfire.com/music/HarpOn/maintassemb.html#cx12work
suggest removing some of the material from both ends of the CX's Spring
retainer plate. The object is supposed to be to facilitate disassembly.

> The reasoning you suggest for filing the
> edges sharp makes sense, but I think that doing so creates a new problem.
I
> agree wholeheartedly that the CX spring is the weak point of the design.
> I'm sure that machining the culprit sharp corners in the production of the
> instrument to a shape that would conform to the inside surface of the comb
> at the key points of contact would cost several times what it does to
simply
> make that sharp-edged corner.  This is a typical management decision made
to
> cut manufacturer's cost.

(I disagree- I think the corners were left square to act as an indexing
device. -S)

> However, IMHO, filing the sharp corners round as you (and G) suggest is
not
> the answer to this manufacturing shortcoming.  The reason I say this is
that
> once the stock spring is properly installed the sharp corners, though the
> wrong shape, ~are~ spaced the appropriate distance apart so that the slide
> is prevented from moving along its length.  That's the whole idea behind
> making the comb slots half the full thickness of the spring in the first
> place.  The "field modification" that you suggest makes the tabs more the
> correct shape, but it narrows the distance between the points at either
end
> of the spring where they would otherwise contact the comb and prevent the
> spring from moving longitudinally.  Filing the edges back even further
> compounds this problem, in my view.  The result?  The modified CX becomes
a
> veritable hand grenade.  If ever there is a significant shock or the
> instrument is dropped, the spring can be bumped or even move due to its
own
> interia.  Because there is nothing stopping the spring from moving in
either
> direction along its length, the spring can easily pop out, causing the
> harmonica to explode!  (Please don't ask me how I discovered this.  :)
>
> I think you'd agree that the real problem caused by the sharp corners
occurs
> primarily if not exclusively during the assembly and disassembly
processes.
> Everything's fine once the (stock) instrument has been properly assembled.
> Therefore, I contend that the best approach to avoiding damage to the comb
> from the sharp corners is ~very~ careful and well-practiced spring
> installation (and removal) technique.  You have to: 1) maintain a firm
grip
> on both ends of the comb and apply even pressure to both ends of the
spring;
> and 2) be very vareful not to release the pressure you apply to the spring
> as you slide it along its length and insert it carefully into the slots in
> the comb until it is properly seated.  The reverse procedure should be
used
> to disassemble the harmonica.  If you do this carefully, you will do no
> damage.  It's only when the tension you've applied to the spring is
released
> before it is in the proper position relative to the comb slots on either
end
> that damage is a problem.
>
> At least that's the way I see it!  8^)
>
> Respecfully,
>
> Michelle

Hey, Michelle, thanks for sticking your neck out on this one. I just want to
"testify".

Mr. G & Mr. Sigfried are acknowledged experts about harmonicas - certainly
they'd never advise us to do anything detrimental to the health of our
instruments. In fact, their sterling reputations make it pretty hard to
disagree with EITHER of them (let alone BOTH!). That takes some guts.

You & I were discussing this mod last week off list, but since I hadn't seen
the page referenced above, I didn't "get it" - I thought you were
referencing the SLIDE spring (and couldn't for the life of me figure why
anyone would want to modify THAT!), and I didn't pursue a clarification with
you.

After seeing the photos on the subject modification, I immediately thought
"why would I want to do THAT?"

For those listers not familiar with a CX, that spring on the back of the
harmonica is a veritable "Jesus Nut"...although it will hold after the
referenced modification, (and MIGHT not give you problems), it opens the
possibility for disaster where none existed before....sort of like filing on
your gun's tirgger shear, or removing the safety.
(Sure it CAN be handled that way, but SHOULD you?)

Probably a little more attention to the CORRECT disassembly steps would be a
better course than modifying one's harmonica in a manner that could allow
disfunction.