It's hard to explain but these experiments are stressful for months...you do something you think makes sense, and maybe it works or maybe it doesn't, but you have like 3 months of work put into something. When it fails, it blows. Mostly they have worked...
Jangle_JamieScottish HighlandsNewDe Rijk, some Gitanes and quite a few others
Posts: 466
Hi Paul, can you tell me how you made your body mould please? I need to make one.
I'm ok with cutting out the exact outline for the sides (bandsaw, then finish with a bobin sander), but I'm not sure how to get that curved base where the back sits. You may have described it before, but I don't see it here. Thanks!
that one is tricky. It's an irregularly shaped dish where the apex is where the top of the pliage would be. I did it in my CAD program and machined it on my CNC. It would be pretty tough to do by hand.
Your options are
1) Do the top in a radius dish: problem there is that if you do a full radius dished top, the apex is going to be closer to the soundhole, so the bridge will be lower in relation to the neck. I think that's probably what a lot of people do.
2) making the pliage and then glueing in the braces with the radius you want, not in a mold. This is sort of a classical guitar method (Torres did this, minus the pliage, I think).
3) However Selmer did it, maybe that's some variation on #2, I'm not sure tbh.
Jangle_JamieScottish HighlandsNewDe Rijk, some Gitanes and quite a few others
Posts: 466
Thanks.
The only thing I can think of so far is making the back and top shapes out of styrene and then laying fibreglass over the top, reinforced on the reverse.
But you have to account for the drop between the bridge and tailpiece. Without that you lose break over angle and mess with your string tension. Same as with the radius dish.
That's what the pliage accomplishes and my irregular dish immitates. I don't like the pliage acoustically but it gives the bridge height.
I suppose you could just make a taller bridge. Somewhat heavier though.
The strings want to fold the guitar in half at the neck joint. In most guitars that brace takes the pressure from the end of the fingerboard and spreads it out towards the sides.
In my guitar because the neck is floating and the pressure is sitting near that area, that brace takes a ton of downward pressure and puts it into the sides. In my guitars since the sides are so strong, it makes a rigid beam to equalize all those forces. It's necessary in all sorts of guitars but for mine it's imperative that it's solid.
When you look at the Chaldni patterns, you can see that in most guitars very little is happening from the soundhole to the neck, so I have no problem making that pretty beefy. And my neck blocks are massive as well.
Jangle_JamieScottish HighlandsNewDe Rijk, some Gitanes and quite a few others
Posts: 466
Ok, I have a couple of questions. Please forgive me if they're obvious!
The first is this: Why not have the neck as one piece that goes into the body, rather than a separate neck and neck block which needs to be joined?
The second question is more of a design idea. To prevent the force of the string tension from buckling the top, could there not be a strut (carbon/aluminium box section) which runs from the neck block to the tail block, just under the top in the centre? It would be under compression, and would not need to be in contact with the top or any braces. It would obviously be visible through the soundhole (perhaps there could be a twin soundhole design that hides it). This would allow for possibly lighter bracing and more fine acoustic tuning of the top rather than structural bracing.
Comments
me too! 🙄
It's hard to explain but these experiments are stressful for months...you do something you think makes sense, and maybe it works or maybe it doesn't, but you have like 3 months of work put into something. When it fails, it blows. Mostly they have worked...
Hi Paul, can you tell me how you made your body mould please? I need to make one.
I'm ok with cutting out the exact outline for the sides (bandsaw, then finish with a bobin sander), but I'm not sure how to get that curved base where the back sits. You may have described it before, but I don't see it here. Thanks!
that one is tricky. It's an irregularly shaped dish where the apex is where the top of the pliage would be. I did it in my CAD program and machined it on my CNC. It would be pretty tough to do by hand.
Your options are
1) Do the top in a radius dish: problem there is that if you do a full radius dished top, the apex is going to be closer to the soundhole, so the bridge will be lower in relation to the neck. I think that's probably what a lot of people do.
2) making the pliage and then glueing in the braces with the radius you want, not in a mold. This is sort of a classical guitar method (Torres did this, minus the pliage, I think).
3) However Selmer did it, maybe that's some variation on #2, I'm not sure tbh.
Thanks.
The only thing I can think of so far is making the back and top shapes out of styrene and then laying fibreglass over the top, reinforced on the reverse.
...or the classical method!
...or make a plaster cast of my Dupont Busato
Just glueing curved braces to the top could be a really easy and effective way to do it. I don't know.
But you have to account for the drop between the bridge and tailpiece. Without that you lose break over angle and mess with your string tension. Same as with the radius dish.
That's what the pliage accomplishes and my irregular dish immitates. I don't like the pliage acoustically but it gives the bridge height.
I suppose you could just make a taller bridge. Somewhat heavier though.
Big Carbon Fiber Glueup.
Why does that brace above the soundhole have to be so massive? I don't mean your guitar, just the design wise, it's the same on my guitar.
The strings want to fold the guitar in half at the neck joint. In most guitars that brace takes the pressure from the end of the fingerboard and spreads it out towards the sides.
In my guitar because the neck is floating and the pressure is sitting near that area, that brace takes a ton of downward pressure and puts it into the sides. In my guitars since the sides are so strong, it makes a rigid beam to equalize all those forces. It's necessary in all sorts of guitars but for mine it's imperative that it's solid.
When you look at the Chaldni patterns, you can see that in most guitars very little is happening from the soundhole to the neck, so I have no problem making that pretty beefy. And my neck blocks are massive as well.
Ok, I have a couple of questions. Please forgive me if they're obvious!
The first is this: Why not have the neck as one piece that goes into the body, rather than a separate neck and neck block which needs to be joined?
The second question is more of a design idea. To prevent the force of the string tension from buckling the top, could there not be a strut (carbon/aluminium box section) which runs from the neck block to the tail block, just under the top in the centre? It would be under compression, and would not need to be in contact with the top or any braces. It would obviously be visible through the soundhole (perhaps there could be a twin soundhole design that hides it). This would allow for possibly lighter bracing and more fine acoustic tuning of the top rather than structural bracing.