Dive in, Sink, swim or just dog paddle around a bit.

[DarwinStrings]

More on the flat top tail piece with pictures.

I had no idea how to go about this guitar especially the top. After thinking about the string break angle a bit I realised it could only be low cause I don't want the strings much higher off the board than a usual flattop. After buying Trevor and Gerard's books I wanted to have a go at those curved braces so I did. I thinned the panels by ear before I got the book . There were a few things I knew I didn't want though like a heel or Stainless steel plate on the back. So far this top just don't feel right but the break angle will be low so I may get away with it, if not it's off with it's top and try again I only used some not so great WRC I had laying around and also used WRC for the curved braces.

I added those side mass bolts too. Now there was a good idea. Instead of me trying to bend my sides thick as usual, I could go thin and then add the weight later, who would have thought I had to get a new neck joint cause I want to get rid of that bit of stainless I have been using that breaks up the back wood look but I still didn't want a heal and want to be able to remove as well as adjust the neck easily. So I went to the top of the local mountain(about 30m above sea level) carrying a small Styrofoam box and had a bit of a meditate.

UTB already in place, glued to the head block and shaped in the dish.

anzlfUTB.jpg (86.66 KiB) Viewed 10430 times

I didn't like the idea of someone in the future being able to wind a bolt through T nuts and out the side of the guitar so I used SS dome nuts and epoxy. I love the Frankenstein look too.

anzlffranky.jpg (86.4 KiB) Viewed 10430 times

If you can't work out whats going on there just ask.

anzlfneck1.jpg (77.44 KiB) Viewed 10430 times

anzlfneck2.jpg (71.11 KiB) Viewed 10430 times

I couldn't resist those braces. It feels a bit dodgy but I will give it a shot and see what happens.

anzlftop.jpg (84.71 KiB) Viewed 10430 times

I won't be working on this again for a few weeks cause of other projects but will let you mob know how it goes as it goes. Oh and by the way this is my first "Cyclone Carlos" guitar. Back, sides and neck compliments of Cyclone Carlos and the local council.

Jim

Life is good when you are amongst the wood.

[jeffhigh]

I've got my doubts about that bracing, Jim
But why don't you just calculate what the downforce will be and place that weight on the bridge area for a couple of weeks and see what it does, before you close the box.

[ozwood]

Hi Jim,

I have seen just about every permentation of Falcate tried at the AGMS, and Ummmm I think Jeff might be right , a Fellow tied something pretty much the same , granted it was a Dreadnaught , it sounded great for a while then bellied , then a bit more and then well it was dead.

But as I said it was a Larger Guitar , so give it a whirl.

Cheers,

[DarwinStrings]

I keep walking back to it and pressing down where the bridge would be and I agree it won't work. That would be a handy calculation Jeff if you don't mind helping me out there the scale is 647.7mm, tension is about 70kg and the break angle will be about 174 degrees.

Jim

What is a AGMS Paul?

[DarwinStrings]

I guess a brace right across the board over the patch would hold it up, any other ideas?

Jim

[jeffhigh]

From Here
http://liutaiomottola.com/formulae/downforce.htm
Using break angle of 180-174=6 deg gives 7.33kg downforce
Yes a brace straight across under the bridge location is what I would do, and probably another at the back edge of the soundhole

[DarwinStrings]

Cheers Jeff, I bookmarked that page. I reckon I have been shoving down with a bit more that 7kg but I still don't like the amount of deflection. I guess now those curved braces could have been straight if I span the board but it was good practice as I will build one of Trevor's sooner or later.

Jim

[jeffhigh]

Trevor's falcate is really designed to resist rotational forces rather than downwards, and you only have half of it there anyhow.....

[DarwinStrings]

Yep, I realised that but also figured there is a lot less force going on here and would rather remake a top than over built it like those balsa lattices I made. Oh while I have you Jeff, does the rotational force at the front of a normal bridge equate to downwards force and if so would it be more that 7kg or so?

Jim

[nnickusa]

I don't kow for sure, but my simple mind suggests that the rotational force of the bridge is significantly greater than the downward force of the bridge with a tailpiece. At least, I hope so, s=as one of my projects has simple ladder bracing on the top, and not one is near the bridge, which sits only on the top plate, without any reinforcement.

I think the physics is totally different, but it's too late to ponder that stuff. I'm shutting up early aned going home

[jeffhigh]

Yep, I realised that but also figured there is a lot less force going on here and would rather remake a top than over built it like those balsa lattices I made. Oh while I have you Jeff, does the rotational force at the front of a normal bridge equate to downwards force and if so would it be more that 7kg or so?

Jim

Depends on how you look at it and how far in front of the bridge, but it is balanced by an upward force behind the bridge You have a moment rather than a force, whereas with the floating bridge and tailpiece there is just a downward force

[DarwinStrings]

Cheers again Jeff and G'day Nick.

Jim

[Trevor Gore]

I have seen just about every permentation of Falcate tried at the AGMS...

Yes.....! Just because it's curved doesn't mean it'll work!

However, the nice thing about bolt-on necks is that it's real easy to change a top.

[DarwinStrings]

Yes.....! Just because it's curved doesn't mean it'll work!

Ha! I reckon you are teaching me a lesson I already learned today so thanks as it always takes a few times to hammer it into my head. It also good practice for getting used to this West system 105 stuff too.

Jim