Bridge patch thickness
- Thread starter Johni
- Start date
Pat Eaton
Well-known member
I built a couple of Hana Lima Tenors and I think I used wood left over from the top or back wood. I have these pieces sanded to 1.7 to 2mm (wood dependent) when I start the builds.
If you email Hana Lima they are very helpful answering questions.
If you email Hana Lima they are very helpful answering questions.
sequoia
Well-known member
You know I never really obsessed over this part of the build although I suppose it could be important. I just make mine out of sanded top cut outs that are about a .1 of an inch thick or about 2.5 mm I suppose. I don't sweat it. It is important though that the grain be perpendicular to the top, sound board grain. Now the footprint of the bridge patch, that might be important...
mikeyb2
Well-known member
I've read that with a pin bridge , it's actually best to have the grain around 45 degrees rather than quartered. This is to guard against splitting. That seems to make sense. Mike.
I will also add that if you intend to use a string through bridge you probably want to consider a "hardwood" for your patch instead of Spruce as this will keep your beads or keepers from denting into the patch.
If you really want the best answer to your question though my opinion is to talk to the folks at Hana Lima as a ukulele design is based off of how all the parts work together as a system, both structurally and sonically. The other piece of this discussion as Sequoia mentions is the footprint being important. Typically you want it larger (footprint) than the bridge and rounded on the wings to prevent splitting from the rotational forces put on the top. But again think of it as the sum of all parts, not bit by bit....
All the best on your build!
If you really want the best answer to your question though my opinion is to talk to the folks at Hana Lima as a ukulele design is based off of how all the parts work together as a system, both structurally and sonically. The other piece of this discussion as Sequoia mentions is the footprint being important. Typically you want it larger (footprint) than the bridge and rounded on the wings to prevent splitting from the rotational forces put on the top. But again think of it as the sum of all parts, not bit by bit....
All the best on your build!
Hardwood will have to be for the next build. I ran with the thickness info yesterday and used leftover top plate material and simply ran it at 90 degrees to the top. Plans called for a 4x1 piece which keeps the patch inside the outer tone bars. That’s how it was glued up.
Good thoughts everyone...I’m appreciative of the discussions of the “how’s and why’s.”
“Rotational forces” isn’t a term I’ve encountered yet. My knowledge is limited to the idea of seasonal moved across the grain. I was concerned about the bridge patch being laid across the grain of the top but I thought that once the bridge gets laminated to the other side, it will be stable like a little section of plywood. Not sure if that thought matches reality?
Good thoughts everyone...I’m appreciative of the discussions of the “how’s and why’s.”
“Rotational forces” isn’t a term I’ve encountered yet. My knowledge is limited to the idea of seasonal moved across the grain. I was concerned about the bridge patch being laid across the grain of the top but I thought that once the bridge gets laminated to the other side, it will be stable like a little section of plywood. Not sure if that thought matches reality?
Beau Hannam Ukuleles
Well-known member
I think you are confusing quarter sawn wood (in cross section) with the angle of grain in relation to looking at it from the 'top'.
mikeyb2
Well-known member
Beau, I'm not confused with respect, although I may have not explained it very well. I'm talking of looking at the endgrain of a bridgeplate. Rather than have the grain lines vertical as in quarter sawn, they are angled maybe somewhere between 30 and 60 degrees(45 would be ideal). I hope this makes more sense. Cheers Mike.
sequoia
Well-known member
Due to forces pushing down on the saddle from the tension of the strings, the bridge wants to move down in front and up in back (rotate). This tends to move the saddle forward slightly which can change the scale length and thus affect intonation.
And yes, think "plywood".
Thanks for posting your video....one person here who found it helpful. Interesting to use a carbon fiber bridge patch/plate. I love the idea of the gems.
Beautiful work BTW.
Beau Hannam Ukuleles
Well-known member
Hi Mike- OK- I know what you mean now- ummm... i've not heard that one.
However, It is a good idea to not have the grain running on the same line as the bridge pins/holes etc (not looking at the end grain but as you look at it straight down).
Beau Hannam Ukuleles
Well-known member
hahha- i certainly don't post videos with the thought they will ever be of interest to more than a handful of people!
Ive been using the gemstones for a few now with no problems. Beads are also good but I assume everyone is like me and would drop and lose them- so i prefer the permanent gem stones- it all works though.
