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Okinawan sanshin build
- Thread starter lbridenstine
- Start date
Hi Lisa,
I mixed up a few quotes so that I could answer them in a hopefully logical fashion:
It will be a hybrid instrument, and a good learning opportunity. I'm sure that she'll appreciate that you made it for her.
I never used Eastern red cedar, but since it is lightweight and grows slowly (which usually means an even and fairly strong cellular structure), it might work well. I don't know, though - that's just conjecture.
In any case, most soundboards or tops are made from quartersawn wood that is split so that the fibers run almost exactly parallel to the length of the board (and then milled flat or arched subtly afterward). A board that has a lot of "runout" (fibers that are not parallel to the length of the board) will tend to split over time when loaded as an instrument top or soundboard is.
As for the top, I would encourage you to experiment with different options (once you have the other parts made and can string it up). Find a temporary attachment system (maybe double sided carpet tape, or hot melt glue on the outside of the intersection of the pieces, not between them, which would be too hard to separate), and try a few options. Maybe: your walnut, Eastern red cedar, and 3mm baltic birch plywood.
Then, ask a band director or instrument tech at a music store for a used drum head (they are nearly all synthetic today, not skin), and attach it with a few thumbtacks, followed by a really tight wrapping of strong thin rope around the perimeter. See if any of the four options jumps out and says "I'm the one!" when you hear/play them.
Here's how I see your options regarding the back and/or sound hole or f hole(s) (like a violin):
If it is a closed body with a stiff back, then air is trapped inside and acts as a strong, stiff spring which inhibits the motion of the top (making the sound very soft). This would be like a closed or sealed speaker design, which takes a lot more power to drive effectively (but has other advantages in a speaker).
So, in this case, you would need a sound hole or f hole(s) like a violin to allow the air inside to escape and not inhibit the top movement. The sound hole could be on the side or the back; it doesn't necessarily have to be on the top. This is like a ported speaker design.
If it is closed body with a very flexible back, then the deflection of the top will, via the air inside, deflect the back in the same direction as the top. Think of a drum with two heads; when you deform the top head down with a drumstick, the bottom head moves down also (its flexibility allows it to give enough to accommodate the air inside). This is like a speaker design with a passive radiator (a second speaker cone with no magnets which acts as a positive and negative air reservoir and also moves air outside the enclosure, adding to the audio output). In this case (membranes on both the top and back of your sanshin), you could get away without a port, or maybe with just a small hole somewhere.
The third option, no back, is the simplest design (simplest doesn't necessarily mean best). It would be like an open back speaker cabinet, relatively loud and efficient. No sound hole would be necessary.
Once again, if you can experiment with an easily removable back, it would make it easier to decide which way to go.
I like that tailpiece design much better. It's much more controllable. The angle of downforce or downbearing (the amount by which the strings are deflected from their straight line path as they cross the bridge) is a critical component of many acoustic instrument designs. Too large an angle means too much force on the top, which can mean a very short sustain (the instrument is "choked"), or even structural failure of the top (if the top cannot withstand that much force). Too small an angle can mean a tiny, thin tone.
Your tailpiece design above lends itself to experimentation with the angle of downbearing; you can design a temporary one which lets the strings leave from lower or higher points, altering the angle as the strings cross the bridge. I would set downbearing as lightly as works well acoustically; the less force on the top, the longer your top might last.
Though I really like the bridge design you posted earlier from a visual aesthetic standpoint, I would recommend using a more standard sanshin bridge design.
While you can experiment with different angles of deflection via the bridge height, this will change the height of the strings above the neck/fingerboard. That is why I am recommending using an adjustable height tailpiece to change the angle of downbearing instead. Once you find the optimal angle of deflection and tailpiece height, you can make your "real," permanent tailpiece with the strings exiting at that height.
I mixed up a few quotes so that I could answer them in a hopefully logical fashion:
It will be a hybrid instrument, and a good learning opportunity. I'm sure that she'll appreciate that you made it for her.
I never used Eastern red cedar, but since it is lightweight and grows slowly (which usually means an even and fairly strong cellular structure), it might work well. I don't know, though - that's just conjecture.
In any case, most soundboards or tops are made from quartersawn wood that is split so that the fibers run almost exactly parallel to the length of the board (and then milled flat or arched subtly afterward). A board that has a lot of "runout" (fibers that are not parallel to the length of the board) will tend to split over time when loaded as an instrument top or soundboard is.
As for the top, I would encourage you to experiment with different options (once you have the other parts made and can string it up). Find a temporary attachment system (maybe double sided carpet tape, or hot melt glue on the outside of the intersection of the pieces, not between them, which would be too hard to separate), and try a few options. Maybe: your walnut, Eastern red cedar, and 3mm baltic birch plywood.
Then, ask a band director or instrument tech at a music store for a used drum head (they are nearly all synthetic today, not skin), and attach it with a few thumbtacks, followed by a really tight wrapping of strong thin rope around the perimeter. See if any of the four options jumps out and says "I'm the one!" when you hear/play them.
Here's how I see your options regarding the back and/or sound hole or f hole(s) (like a violin):
If it is a closed body with a stiff back, then air is trapped inside and acts as a strong, stiff spring which inhibits the motion of the top (making the sound very soft). This would be like a closed or sealed speaker design, which takes a lot more power to drive effectively (but has other advantages in a speaker).
So, in this case, you would need a sound hole or f hole(s) like a violin to allow the air inside to escape and not inhibit the top movement. The sound hole could be on the side or the back; it doesn't necessarily have to be on the top. This is like a ported speaker design.
If it is closed body with a very flexible back, then the deflection of the top will, via the air inside, deflect the back in the same direction as the top. Think of a drum with two heads; when you deform the top head down with a drumstick, the bottom head moves down also (its flexibility allows it to give enough to accommodate the air inside). This is like a speaker design with a passive radiator (a second speaker cone with no magnets which acts as a positive and negative air reservoir and also moves air outside the enclosure, adding to the audio output). In this case (membranes on both the top and back of your sanshin), you could get away without a port, or maybe with just a small hole somewhere.
The third option, no back, is the simplest design (simplest doesn't necessarily mean best). It would be like an open back speaker cabinet, relatively loud and efficient. No sound hole would be necessary.
Once again, if you can experiment with an easily removable back, it would make it easier to decide which way to go.
I like that tailpiece design much better. It's much more controllable. The angle of downforce or downbearing (the amount by which the strings are deflected from their straight line path as they cross the bridge) is a critical component of many acoustic instrument designs. Too large an angle means too much force on the top, which can mean a very short sustain (the instrument is "choked"), or even structural failure of the top (if the top cannot withstand that much force). Too small an angle can mean a tiny, thin tone.
Your tailpiece design above lends itself to experimentation with the angle of downbearing; you can design a temporary one which lets the strings leave from lower or higher points, altering the angle as the strings cross the bridge. I would set downbearing as lightly as works well acoustically; the less force on the top, the longer your top might last.
Though I really like the bridge design you posted earlier from a visual aesthetic standpoint, I would recommend using a more standard sanshin bridge design.
While you can experiment with different angles of deflection via the bridge height, this will change the height of the strings above the neck/fingerboard. That is why I am recommending using an adjustable height tailpiece to change the angle of downbearing instead. Once you find the optimal angle of deflection and tailpiece height, you can make your "real," permanent tailpiece with the strings exiting at that height.
This is all really helpful, thank you!
I like the idea of trying f-holes too.
The main reason for the bridge choice is because the standard ones fall over really easily.
I like the idea of trying f-holes too.
The main reason for the bridge choice is because the standard ones fall over really easily.
I'm up to the finishing stage on my build challenge guitar.
So now I can get back to the sanshin! I don't think it should take much longer until this one is in the finishing stage too.
I glued together some pieces to make the tuning pegs out of.
Camphor burl, white veneer, dark brown veneer (I think it might be smoked eucalyptus), white veneer, then wenge.
That should be enough for 4 pegs and of course, I only need 3, so I guess I'll have a backup if I need it.
I'll probably work on this more tomorrow.
So now I can get back to the sanshin! I don't think it should take much longer until this one is in the finishing stage too.
I glued together some pieces to make the tuning pegs out of.
Camphor burl, white veneer, dark brown veneer (I think it might be smoked eucalyptus), white veneer, then wenge.
That should be enough for 4 pegs and of course, I only need 3, so I guess I'll have a backup if I need it.
I'll probably work on this more tomorrow.
These pictures didn't turn out very good.
I started making some of the hardware.
The nut isn't squared yet, that thing is tiny and kind of hard to work with, but there's not much to do after getting it the right shape.
This is going to be the tail piece. I have to make that hole square to fit over the end pin/stick.
My mom said it would make a good pick, so I told her I have an identical piece because it started out twice as thick and I re-sawed it. I'm going to make a camphor burl plug to go in the hole, that way it will kind of match the pegs.
The next step will probably be turning the pegs on the lathe. They look like they should turn out really nice when they're done. I'm going to make it so two sides are flat and two sides are round on the ends that stick out, so there's something to grip onto when you're turning them.
I started making some of the hardware.
The nut isn't squared yet, that thing is tiny and kind of hard to work with, but there's not much to do after getting it the right shape.
This is going to be the tail piece. I have to make that hole square to fit over the end pin/stick.
My mom said it would make a good pick, so I told her I have an identical piece because it started out twice as thick and I re-sawed it. I'm going to make a camphor burl plug to go in the hole, that way it will kind of match the pegs.
The next step will probably be turning the pegs on the lathe. They look like they should turn out really nice when they're done. I'm going to make it so two sides are flat and two sides are round on the ends that stick out, so there's something to grip onto when you're turning them.
Heh. I'm having trouble figuring out how to do thing on one single build. I can't imagine how difficult it would be to juggle three projects where one have a time limit. 
It will be very interesting to see how this one turns out. I don't know anything about sanshins (??) so this one will be interesting to follow for sure.
I have been sporadically looking at your build over at TDPRI as well. It looks very nice.
It will be very interesting to see how this one turns out. I don't know anything about sanshins (??) so this one will be interesting to follow for sure.
I have been sporadically looking at your build over at TDPRI as well. It looks very nice.
Thanks guys! Yeah, it can get confusing, but I have one out of the way now at least for the woodworking part.
Thank you. I keep meaning to go out there and finish them, but either things come up or the weather is crappy or I'm just too tired... Ugh. Hopefully tomorrow.
I think they'll almost look like fancy chopsticks when they're done, haha.
I don't know anything about sanshins (??) so this one will be interesting to follow for sure.
In Japanese, plurals are provided by context, not by modifying the word. So one Sanshin is a Sanshin, and two ore more Sanshin are also Sanshin.
Hopkins
Commercial User
In Japanese, plurals are provided by context, not by modifying the word. So one Sanshin is a Sanshin, and two ore more Sanshin are also Sanshin.
I get to watch an interesting build, and I am learning about Japanese language at the same time. This thread just keeps getting better
I made the tuning pegs today.
I need to start actually doing more than one thing per day on this so I can get it done!
I made the tuning pegs today.
I need to start actually doing more than one thing per day on this so I can get it done!
Those came out really nice! I love the grain.
