Re: [Harp-L] RE: Suzuki Welded Reed/00-90 screws

[Joe and Cass Leone <leone@xxxxxxxx>]

On Oct 10, 2008, at 2:07 AM, Harvey Berman wrote:

> Thanks for the tip for breaking the weld with a reed wrench.  I  
> partially drilled, and then punched the rest of it.  That part came  
> out OK, though your way would be easier.  My problem is that the  
> hole is not centered in the slot.  It is offset .0045 in. to the  
> right.  It looks like all the welds on my Suzuki are done the same  
> way.  I do not understand why they did that.

I don't think it was intentional. I believe that the tooling jig is  
showing wear.

>   You are right about the Honda Reed, and that is what I did.  I  
> shaved it to a beautiful fit in the slot, but is was offset.

We were just talking about Hondas. I think you meant Hohner.   :)
> Smo Joe says to walk the reed with a punch.  I will try that with a  
> scrap plate.  The way it is now, I have a .006 inch gap on the left  
> side of the reed.  Since I like to have a clearance of .0015 I have  
> to either shave or walk the reed over .045 or shave a bigger reed  
> that amount.

You could also oval out the hole in the reed but be careful. They are  
brittle. I would 'swage' it larger with a needle as I have never seen  
a needle file that small in dia. And if I did, I probable broke the  
tip off within 68 seconds.  lol
> As for the 00-90 screw question, the ones I have found are rather  
> expensive.  Smallparts .com wants $15 for a pack of ten.  I use  
> 0-80, which I get from Fastener Express (www.fastener-express.com).  
> They are only $3.00  for 100 screws.

Screws present several problems. For one thing, on a chromo, you  
would need to use a flat head countersink screw from the OPPOSITE  
side from the reed (much like a wheel stud). This way there is  
nothing in way of the wind saver that will go on later. The problem  
with a countersunk head is that they have a flare under the head that  
will 'eat up' HALF the thickness (or more) of the reed plate. Since  
most reed plates are only 1mm or so thick, you have lost your  
'grabbing ability'.

There is an old axiom in the screw business that it is necessary for  
TWO turns to be available to hold. Now that equates to 2 turns per 1  
mm plate thickness,(or 50.8 threads per inch). So, since you have  
already lost half your able grab space, you now need a screw that is  
101.6 threads per inch. A ridiculously fine screw, One which will  
have insufficient peaks and valleys to hold in the relatively soft  
metal. I would use a screw/stud in the 80 tpi range, with the nut on  
TOP of the reed. Backed up with a tiny mylar (1mm id x 2mm od) washer  
as found inside the tuner box from a small portable radio. Which is  
also a source of small nuts. In fact, sheet metal screws from these  
radios & tape players can also be used for many things.

The other alternative is to not even PLAN for the stud or screw to  
have to hold in the plate at all.

With a diatonic, you can have screws with heads. The head can be on  
EITHER side. You can use nuts. They can be on either side.

Now that we have the internet, one can get anything they desire  
(well, almost), but back in the day, the easiest way out was to go to  
a watch repair shop and either use what THEY were using, or getting  
the address of THEIR supplier. Diminutive machine screws come with 2  
(basic) flat head countersunk configurations. 45 degree and 30 degree.

>   They do have the 00-90 brass nuts which are $6.30 for 50.  I like  
> the 0-80 screws better than the 00-90 anyway.  I drill and tap the  
> reed plate, and screw the reed in from the front and do not use a  
> nut.  The 0-80s are much easier to work with, and the nice taper  
> centers the reed nicely.  If the reed hole or plate hole is  
> slightly off center, then I put the screw in from the back, and use  
> a 0-80 nut.  It is a little big, but it works ok.

As for prices, my father in law was a machinist and worked a mach  
called a rotary. It had dozens of spindles on it and would throw out  
small parts by the thousands per hour, but when you get down to parts  
this small, you are talking some pretty weird expensive equipment.

smo-joe
> Harvey Berman
>
>  Brendan Power wrote:
>
> The way to proceed is to first remove the old reed with a reed wrench.
> Simply twist the wrench to the side and the weld will break off. Clean
> up the place where it sat on the reed.
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