Author Topic: Troubleshooting Reelfoot tone boards  (Read 2149 times)

Offline FDR

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Troubleshooting Reelfoot tone boards
« on: August 14, 2014, 07:24:28 PM »
I have been in the shop the past 2 days (retirement has it's benefits) mostly tuning Reelfoot calls and I found one insert that just would not tune. I laid it aside and finished the others then came back to see if I could find the problems with this insert.
 Here is the troubleshooting process I went through, the recovery process to save the insert and some comments along the way to think about:

First I checked the tone channel length. I like about 0.100" of wood between the tone channel tip and the end of the reed. On this insert the tone channel was too long and the call would not "high ball" very well. Now how do you make the tone channel shorter?
I also checked the flatness of the tone board. In checking a tone board for flatness a six inch, rigid, machinist rule is your best friend.  The rule is both square and straight. I just lay the rule on the tone board and check the flatness both side to side and along the length by holding the assembly up to a light source and looking for light coming through the contact surfaces.  This particular tone board was "sway backed" along it's length possibly caused by cleaning up the glue used in making the wedge.  I also checked the length of the wedge and it measured 0.680" which is optimal for my tone board and reed design.
Now, back to the question "how do you make a tone channel shorter".  Remember that the tone channel is cut on a 6 degree slope (angle relative to the centerline of the insert).  If you cut the thickness (depth) of the insert down (top to bottom)  the tone channel, being angled, will become shorter. I have noted in studying antique Reelfoot calls that the thickness of the tone boards ( top to bottom) varies quite a bit between individual calls even from the same maker. I concluded that this thickness variation occurs because of the variation in the drilling angle (manual drilling)  of the tone channel hole by the maker.  To set the correct tone channel length (for a given reed length) the insert was just shaved down as needed.
Can I save my insert?   Yes, if the tone channel is not extremely long or extremely deep.  When cutting down the depth of the tone board a little goes a long way.  I remounted the insert in my jig, making sure the surface of the tone board is parallel with the jig. I used the jig adjustment screws to move the insert up in the jig maybe 1/16 of an inch. Shims can also  be used or a combo of shims and adjustment screws.  I then re-cut the insert and measured the resulting tone channel length. I repeated the process until I had a shorter tone channel  length than required then I used the mill to re-cut the tone channel to the desired length and depth.
The downside to this process is that you now have to make a new wedge but that is simple compaired to making a complete insert.
After completing the new wedge I reassembled the call and gave it a try. Using a known good (tuned) reed the call worked properly including the "high ball". So it is possible to save an insert sometimes.

I hope this brief writeup helps someone else in troubleshooting  and tuning a Reelfoot call insert.

Fred
Fred Roe
Reelfoot, the original duck call. What's on your lanyard?

Offline Henry H

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Re: Troubleshooting Reelfoot tone boards
« Reply #1 on: August 14, 2014, 10:49:45 PM »
Fantastic, Fred, both in terms of write-up and in terms of timing.  I've actually been messing with a toneboard a friend asked me to assess the last couple days, and will apply some of your diagnostics.

This particular one has a flat tone channel (no slope), which I hypothesize is causing tuning problems regardless of what reed variation (thickness, flexibility, width, length) I throw at it.  All of them have to be tumed too low/deep (too much curvature) for my taste to get a good, easy quack and chuckle, yet still run too high and squeal when pushed with much pressure.  I was going to use some clay this weekend to simulate a slope to prove or disprove my suspicion, but reading this recognize you've probably been down this path already.  I'm going to test anyway, but would a flat tone channel display these symptoms?  If not, any other ideas?

Offline FDR

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Re: Troubleshooting Reelfoot tone boards
« Reply #2 on: August 15, 2014, 09:11:03 AM »
It sounds to me like you have too much air going thru the call.  The tone channel may also be too deep at the tip.
I have examined antique calls with a wide and somewhat flat tone channel but they all had some slope.  The best example that comes to mind is a "Bean Lake". They work.
I use 5 minute epoxy and saw dust to fill in a tone channel when I am running experiments. I just filled the channel with the mixture and clamp a waxed flat reed blank to the tone board to smooth it out until dry.  Remove the reed, sand lightly and you are ready to recut the channel.  The wax keeps the reed  from sticking to the surface.

Fred
Fred Roe
Reelfoot, the original duck call. What's on your lanyard?