Re: [Harp-L] Archive search

[Vern <jevern@xxxxxxx>]

If you use 00-90 flat-head screws and nuts, you won't need a tap because the nut has the female threads.  You will need a #55 drill to enlarge the holes in the plate and reed to clear the screw threads. You will need the 82 deg countersink bit to countersink the screw head into the valve side of the plate.

The brass of the reedplate will have a tendency to climb the drill used to enlarge the hole.  Put the plate in a drilling vise if you have one, run the drill fast, and feed it very slowly.  Tape the reed to a piece of wood and hold it with your thumb while enlarging the hole.  Some members of the "old school" don't use drill bits but turn a needle file in the holes.  File a little at a time and quit when the screw will pass through the hole.  

When you use a flat-head screw, the centerline of the countersink cone and NOT the centerline of the hole locates the screw.  Start the countersink gently and let the plate "float" under it so that the bit "finds" the center of the hole.  It is easy to countersink too deeply.  Feed the bit slowly and stop frequently to check it with the screw.  The screw head should be flush with the surface of the plate.  No operation can be perfect and every time you drill and countersink, you introduce a little hole-position error.  

I use 0-80 screws in holes tapped into the reedplate.  You need a #55 drill to enlarge the rivet hole in the plate and a #52 drill to enlarge the hole in the reed.  There are no nuts involved and the screw head holds the reed down. You will need a 0-80 tap and a pin vise to hold it. Then you need a way to cut off and file flush the extra screw length that protrudes on the valve side of the plate.  I use a Dremel tool with an abrasive wheel.

You will also need a needle file to "stretch" the hole in the reed if it isn't exactly on the centerline of the slot on the first try.  I use lubricated 0-80 washers under the heads of the 0-80 screws to lessen the tendency for the reed to turn as the screw is tightened. It also lessens the tendency of the screw to turn if you have to adjust the reed angle with a reed-wrench.

 I frequently have to file a side of the reed hole to get it on the centerline of the slot.  If the reed touches the slot anywhere, it won't play.  The clearance on each side of the reed is less that the diameter of a human hair.  That means that the adjustment has to be practically perfect.

When checking a reed, place it in front of a brightly lighted background...such as a fluorescent tube...and view the clearance around it with one eye closed.  My sunlit concrete driveway works when I'm seated in my windowless garage.

You can get the taps, drill bits, and nut driver at Micromark.

Fist tape the reed into the slot, then turn the plate over.  That way, the nut will stay in the driver or the screw on the tip of a Phillips screwdriver.

Vern


On Feb 1, 2010, at 8:48 PM, joe leone wrote:

> 
> On Feb 1, 2010, at 11:00 PM, Dave Minson wrote:
> 
>> Can anyone tell me how I might get to some of those threads discussing attaching reeds to reed plates with screws, sizes, sources, etc?  I tried to search the archives and came up blank.  Thanks.
>> dave
>> _______________________________________________
> 
> Dave, you will need a .0090 tap, a (small) 82 degree countersink, a .0090 nut driver, .0090 x 1/8" machine screws, and .0090 nuts. You will also need a wire gage drill. I don't recall the size (diameter) right at this time.
> smokey-joe_______________________________________________
> Harp-L is sponsored by SPAH, http://www.spah.org
> Harp-L@xxxxxxxxxx
> http://harp-l.org/mailman/listinfo/harp-l