Re: [Harp-L] Reed slot needs to be shortened

[Zombor Kovacs <zrkovacs@xxxxxxxxx>]

I donno if I understand the problem correctly, but if the slot is too long for 
the reed, why dont you use a longer reed instead?  Just cut it to the right 
length and there you have it. 

Zombor





----- Original Message ----
From: joe leone <3n037@xxxxxxxxxxx>
To: Vern <jevern@xxxxxxx>
Cc: Harp L Harp L <harp-l@xxxxxxxxxx>
Sent: Sat, October 30, 2010 7:50:30 AM
Subject: Re: [Harp-L] Reed slot needs to be shortened


On Oct 30, 2010, at 1:31 AM, Vern wrote:

> If it were me, I would try the following:
> 
> - Make a brass slug the size of the slot and a tad thicker than the plate, 
>maybe .050".
> - Place it in the slot.
> - Carefully hammer it to expand it in the slot.
> - File it even with the surfaces of the plate.
> - Take it back to the EDM for a re-do.

     The only reason I didn't suggest this was because I assumed that there 
would be a reed already IN the slot...and working around it this much would be 
ticklish. With my method the reed could be held high enough out of the way with 
a straight pin to allow the filing work. And I agree, the file should have no 
teeth on the sides.
     Another idea is to drill an overlap hole at the end of the slot and tap to 
receive a brass screw. Screw is then cutoff flush top and bottom and then filed 
with a square file the same width as the slot, (again..no teeth on the sides). 
You wind up with a 'Pac Man' with a square mouth. Resembles a 'circlip'.
> 
> Machinists have been fixing holes this way since rainbows were in black and 
>white.  This just happens to be a rectangular hole instead of a round one.
> 
> If the above isn't practical, then you could try the following.
> 
> - Coat the plate with parting compound and fill the slot with metal-filled 
>epoxy such as JB Weld.
> - When set, file the epoxy even with the surfaces of the plate.
> - Remove the epoxy slug from the slot.
> - Shorten the slug to the desired slot length.
> - Coat the slug with parting compound and clean the plate.
> - Insert the slug back in the slot.
> - Fill the excess length with epoxy.
> - Remove the slug.

     Yes, this is excellent for extreme cases.
> 
> Epoxy doesn't shrink as it sets up and will replicate every tiny detail of the 
>mold.  Once JB Weld has set up, it can be worked almost like metal.
> 
> You should be left with a slot of the desired length.  The longer slug should 
>be fairly easy to file to the desired slot length and check with a micrometer.  
>It will be ticklish business but it might work.  I have never done it myself so 
>there could be unforeseen problems.
> 
> If you use a method that requires filing in the slot, I would cut down a 
>jeweler's file to .080" wide with no teeth on the sides.  This could be done on 
>the EDM whose operator owes you the favor in exchange for the boo-boo on the 
>slot.    ;o)
> 
> Vern
> 
>> On Oct 29, 2010, at 10:56 PM, Doug H wrote:
>> 
>>> I got back some custom made reed plates from my EDM guy only to find that one 
>>>of the slots was mis-cut a about .045" too long (in .040" thick brass - slots 
>>>are .0835 wide).  I recall a discussion here a while ago about how to shorten a 
>>>slot.  I believe epoxy and/or solder were mentioned. My plan would be to try and 
>>>gracefully place a gob of epoxy or solder in the end of the slot and then file 
>>>it into shape.  Or should I try and make a little plug of brass and then solder 
>>>that into place?  (I have lots of brass scraps.)
>>> 
>>> I have 8 of these to fix so it is worth doing a bit of research first.  All 
>>>advice or suggestions will be appreciated.
>>> 
>>> Doug H
>>> 
>> 
>