greenscoe
Well-known member
On 19th May I asked why we all build ukes with the strings tied to the bridge.
https://forum.ukuleleunderground.co...we-tie-the-strings-to-the-bridge-on-a-ukulele
After this forum discussion, I set about to build a flat top tenor with a floating bridge to satisfy my curiosity. Regular readers of this forum will know that I have previously used a cheap Ammoon tenor kit from Ebay to test a soundboard. The laminate top is removed and replaced with the test top.
So once more that’s what I have done, again using Engelmann spruce.
Since the soundboard takes only vertical loading from the strings at the bridge and no string pull forces, the bracing needs only to consider this.
If the soundboard were round and wood had equal strength in all directions, then thinking of a loudspeaker, I would have simply added a circular patch under the bridge. But wood is strong along the grain and weak across the grain, so the soundboard needs additional strength across the grain.
An obvious bracing scheme would therefore use 1 or 2 ladder braces with or without a bridge patch. The location, dimensions and orientation (parallel or skewed) would need to be determined by experiment.
My thoughts however were to use 1 ladder brace under the bridge and a patch either side of this. These patches taper from 2mm to almost zero at their edges, giving more support across the grain than along the grain and most support closest to the bridge. The soundboard is 2mm thick.
The strings are attached to a maple ‘bracket’ on the butt of the box in mandolin fashion. I tried a short bridge (60mm) but think the instrument sounds and feels better with a longer (110mm) bridge which spreads the downward force over a larger area (the notched saddle is a scrap of acacia). There is no noticeable soundboard depression.
I don’t have a particularly good musical ear so characterising the sound is always difficult. Its loud with a percussive quality, it sounds like a spruce topped instrument with that quick and clear response. It has lots of sustain, bass is good, maybe treble is a little weak. I prefer it as a strumming instrument rather than a picking instrument. I am not disappointed with it but its not as warm or rich sounding as my best tenor to date. It's not so different from my other Engelmann instruments and it raises the question of how it could be improved given it's my first stab at a floating bridge instrument.
I am a hobby builder. As always, I post this to encourage others to have a go at your own ideas. I have tried to outline my thought processes, but of course I may be heading in the wrong direction-so follow at your own risk!
If you have made a floating bridge instrument, I for one would be interested in seeing how it was braced and your impressions of the way it sounds.
If you are interested in this thread, there's a follow on thread on a tenor with a floating bridge:
https://forum.ukuleleunderground.co...oating-bridge-tenor-with-segmented-soundboard
https://forum.ukuleleunderground.co...we-tie-the-strings-to-the-bridge-on-a-ukulele
After this forum discussion, I set about to build a flat top tenor with a floating bridge to satisfy my curiosity. Regular readers of this forum will know that I have previously used a cheap Ammoon tenor kit from Ebay to test a soundboard. The laminate top is removed and replaced with the test top.
So once more that’s what I have done, again using Engelmann spruce.
Since the soundboard takes only vertical loading from the strings at the bridge and no string pull forces, the bracing needs only to consider this.
If the soundboard were round and wood had equal strength in all directions, then thinking of a loudspeaker, I would have simply added a circular patch under the bridge. But wood is strong along the grain and weak across the grain, so the soundboard needs additional strength across the grain.
An obvious bracing scheme would therefore use 1 or 2 ladder braces with or without a bridge patch. The location, dimensions and orientation (parallel or skewed) would need to be determined by experiment.
My thoughts however were to use 1 ladder brace under the bridge and a patch either side of this. These patches taper from 2mm to almost zero at their edges, giving more support across the grain than along the grain and most support closest to the bridge. The soundboard is 2mm thick.
The strings are attached to a maple ‘bracket’ on the butt of the box in mandolin fashion. I tried a short bridge (60mm) but think the instrument sounds and feels better with a longer (110mm) bridge which spreads the downward force over a larger area (the notched saddle is a scrap of acacia). There is no noticeable soundboard depression.
I don’t have a particularly good musical ear so characterising the sound is always difficult. Its loud with a percussive quality, it sounds like a spruce topped instrument with that quick and clear response. It has lots of sustain, bass is good, maybe treble is a little weak. I prefer it as a strumming instrument rather than a picking instrument. I am not disappointed with it but its not as warm or rich sounding as my best tenor to date. It's not so different from my other Engelmann instruments and it raises the question of how it could be improved given it's my first stab at a floating bridge instrument.
I am a hobby builder. As always, I post this to encourage others to have a go at your own ideas. I have tried to outline my thought processes, but of course I may be heading in the wrong direction-so follow at your own risk!
If you have made a floating bridge instrument, I for one would be interested in seeing how it was braced and your impressions of the way it sounds.
If you are interested in this thread, there's a follow on thread on a tenor with a floating bridge:
https://forum.ukuleleunderground.co...oating-bridge-tenor-with-segmented-soundboard
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