Re: [Harp-L] 0-80 x 1/16" screws for reed replacements



I use 0-80 x 1/8 SS screws that are available in quantities of 100 @ 7c ea.  from McMaster Carr.

I use them on chromatics which require that the tips of screws be flush with the plate where the valve is glued on. I suppose that diatonics can tolerate some protrusion of the screws beyond the plate.

This means that 1/16 = .0625" screws are too long.  The ideal length would be the thickness of the reed-plate  (.040") + the thickness of the reed (.012") = .052"  which is, of course, not a standard length. I sometimes use a .015" washer under the screw head for which a 1/16" screw would be too short.   I posit that no standard length will be satisfactory.  

Solution 1.
I have ground diagonal cutters so that the cutting edge is at the very edge of the jaws, like this:  \ /  they were formerly like this: > <.
I after attaching the reed, I nip off the part that protrudes from the other side of the plate.  This leaves a small burr that I remove with just a touch of a Dremel abrasive wheel.

Solution 2. 
Some technicians object to Solution 1.  because there is a danger of marking the plate with the abrasive wheel. For them I suggest using Solution 1. on a scrap plate, then transferring the screw.

Solution 3.
I made a tool for shearing off an 0-80 screw to any precise length.  Because I used a table-top milling machine, various bits, propane torch, a fire brick, SS foil, and tool steel material; this approach may not be open to everyone.  However, those interested in replacing reeds are technicians, many of whom have such tools.

Anyone interested can email me off-list for pictures of the modified diagonal cutters and/or the shearing tool.

Vern

 






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