Reed Replacement Trouble
Kinya,
I'm stumped on this. I have this trouble often. This reed I replaced, A Harp 5 Draw, is not sounding cleanly. It's in tune but sounds as if it's hung up. If you see the photo, i think it looks pretty well centered in the slot. I tried three brand new factory reeds in this slot and same trouble. I recorded a demonstration of it but it looks like I can't paste an mp3 into this forum.
Any idea what might be causing it?
Hello Paul
Guess what topic I will be covering in this afternoon's session of Harp Tech Workshop II, held in my studio in San Jose, CA? Too bad I can't transport you here!
There is nothing more annoying than a snagging reed--especially a new one.
I am very suspicious that your reed is "hung up" somewhere within the slot--most likely at the rivet end. This is especially prevelant with sized (embossed) reed plate slots--due to the close tolerance work.
TIP: With magnification in front of, and a good light source behind the reed, you will be able to identify the hidden "bolders in the road". These can be eradicated by sliding a .001" shim (feeler gauge) inbetween the reed and the reed slot.
Another thing to check out is to make certain that the mating surface between the bottom side of the new reed and reed plate are ABSOLUTELY FLAT. If not, the crooked reed will attempt to corkscrew through the slot and hit the sides (for review, watch the opening chase scenes from Matrix One, when our heroin, Trinity she dives through one high rise window, into the next, rolling down the stairs--wow!)
Your Harpsmith, Kinya
I will try the shim, thank you. I'm also suspicious that the reed is not sitting flat on the plate. To attempt to fix this, I've sanded the hole on the plate down with an Emory board but it still feels scratchy to me. How do you get the surfaces smooth again after sanding?
My other concern is that I have not tapped the hole in the plate square to the plate so the reed is twisted. I doubt there's a fix for that.
Thanks.
Hello Paul, Let's try this step again before moving on to more drastic measures:
- Magnification should be at least 2x ~ 3x the actual size of your work (it should look as large as a Buick Skylark ;o)
- Lighting should be a minimum of 100 foot candles. If you don't have a good light source--move your work outside into the sunlight
- If the reed is "catching" on something, it should now be visible and obvious
- With your shim and/or reed wrench, pivot your reed within the slot until you see and even sliver of light peering around the sides and tip of the reed slot.
In the meantime, please advise:
- Are you using 0-80 size machine screws?
- What size drill bits do you have on your bench?
- Is your emory board more gritty than 320g?
Your Harpsmith, Kinya
You r rock Kinya. Despite how much that Reed looked centered to the naked eye, under magnification it was not. Sticking the shim in there kicked it right over. Thanks!
Excellent! Well done Paul.
Your Harpsmith, Kinya
Kinya, if I'm buying new reeds from Hohner, rather than using donors from old harps, would it just be easier for me to use rivets rather than screws?
Yes and No.
For me, I am a 100% machine screw Harp Tech. For Richard Sleigh, however, he enjoys the old school rivet approach.
Please view Richard's video at http://hotrodharmonicas.com
This should help your decision making process ;o)
Your Harpsmith, Kinya
