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Triple florentine cut away help
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=42438		 Page 1 of 6
Author:  Duhjoker [ Fri Jan 10, 2014 2:50 pm ]
Post subject:  Triple florentine cut away help
After looking at Michi Matsudas pieces I've decided I want to do a lil more flare to my next guitar design. I want to do a triple florentine cut away. What I mean by triple ( see pic ) is to take the bottom bout of the guitar body and cut out and reverse the curve where it goes in. The only problem I see and whats keeping me up at night in doing any florentine cutaway is clamping all the side pieces together and since clamps don't clamp angles it's really killing me. Also what do I do about the tail block? Any help would be appreciated

Image

Sorry not a good pic and the lower line hasn't been refined just wanted to show the shape.
Author:  PeterF [ Fri Jan 10, 2014 3:54 pm ]
Post subject:  Re: Triple florentine cut away help
Hmmm maybe I shouldn't have told you to look at his designs... :mrgreen:
It's certainly a unique idea! This tutorial give a good idea of how to do a florentine cutaway: http://www.luthiersforum.com/forum/view ... t=12750%22
I don't know what it would do to the sound - you'll be taking a lot of air volume out of the box and the lower bout is the most active part of the top. As for the tail block, just make the corner blocks a bit bigger than normal.
Author:  the Padma [ Fri Jan 10, 2014 4:19 pm ]
Post subject:  Re: Triple florentine cut away help
Go study the molds for making Violin family "C" bout corners.

Then there is the way me do em.

http://www.luthiersforum.com/forum/viewtopic.php?f=10122&t=32900

Oh and go get thy self a band saw.

Also be aware that corners like these in the lower bout take a lot of beating from handling. And so suggest executing them like in the link me posted as opposed to banding them or the link Peter posted.

Also give some thought to were them two bottom corners fit on a stock issued guitar stand.

Sorry Peter, but me thinks a tail block is still needed...you know...for the strap button. laughing6-hehe
Author:  SteveSmith [ Fri Jan 10, 2014 4:38 pm ]
Post subject:  Re: Triple florentine cut away help
Would make it easy to park on your thigh and play it classical style :)
Author:  Duhjoker [ Fri Jan 10, 2014 4:50 pm ]
Post subject:  Re: Triple florentine cut away help
Lol!!! Yea that's me Mr. Unconventional. Hmmm I hadn't really thought about what taking so much out of the lower bout would do. I could make the upwards dip shallower or move the angle of the cutout. I know I've seen something like it before though I can't find any pics. I appreciate the posts and links, it really gives me a good idea of what I need to do next.
Author:  Rod True [ Fri Jan 10, 2014 5:20 pm ]
Post subject:  Re: Triple florentine cut away help
PeterF wrote:
Hmmm maybe I shouldn't have told you to look at his designs... :mrgreen:
It's certainly a unique idea! This tutorial give a good idea of how to do a florentine cutaway: http://www.luthiersforum.com/forum/view ... t=12750%22
I don't know what it would do to the sound - you'll be taking a lot of air volume out of the box and the lower bout is the most active part of the top. As for the tail block, just make the corner blocks a bit bigger than normal.


There you go, I thought I'd posted a tutorial of sorts many moons ago. Still do it the same way.
Author:  Duhjoker [ Fri Jan 10, 2014 11:01 pm ]
Post subject:  Re: Triple florentine cut away help
Just got done refining the shape I want. I kinda like that lower bout cut away so I took my tail block to my template and measured where I could get it high enough and still left plenty of room for the lower tone bars. About 3/4 inches. From there I took a piece of sacrificial side material and bent it while someone marked the outline. There's still plenty of action for the lower bout to function properly. If anything I think I'll get a reduction in loudness which also may fix my sustain problem in E-mode. I'm using all hardwood. Sorry I just love the curly maple. I went with no sound hole and a hard top on my last guitar as some of you know. It's still loud enough the people upstairs can hear when I'm jammin on it. IDK, I think it'll work.

Image
Author:  Duhjoker [ Sat Jan 11, 2014 2:12 am ]
Post subject:  Re: Triple florentine cut away help
Figured out how to do this a lil easier I think. I was drawing out the bottom bout on a piece of card board so I could make one of those glue jigs when I realized I could make a caul that fits inside my frame. It's perfectly square so all I have to is put in the lil triangle pieces to join the sides then clamp them to the frame. Same thing with the top cut ways.
Author:  Duhjoker [ Sat Jan 11, 2014 9:02 pm ]
Post subject:  Re: Triple florentine cut away help
Worked on my bending form today attaching all the clamps and straightening my pieces of steel for the new form. Also made the caul for the bottom which coincidentally I can use as a seperate bender for the bottom inverted curve.

Image

Image
Author:  Duhjoker [ Sun Jan 12, 2014 11:01 pm ]
Post subject:  Re: Triple florentine cut away help
Finished up my jigs and cauls for the florentine tops and bottom and bent my first side. I decide to make a seperate mold for the top cut outs rather than over a pipe. I experimented yesterday over a pipe and didn't like the results so since I had the shape cut out for the cauls i might as well use it. Let me tell you using a gun AND tightening bolts at the same time is hell. I usually have help but wanted to try. Any way I solved this by getting the the area I was bending hot then tightening and reheating.

Image
Author:  Duhjoker [ Sun Jan 12, 2014 11:03 pm ]
Post subject:  Re: Triple florentine cut away help
Image
Author:  Duhjoker [ Tue Jan 14, 2014 6:22 pm ]
Post subject:  Re: Triple florentine cut away help
I've been looking for info on tail blocks and what exactly they do and are needed for and can't find any explanation. The reason I asked is because I ran across an article where a guy kerfed his tail block to get it to fit properly and to keep it from ghosting later on. I couldn't find any other info or pics as the pics had been removed. It occurred to me that I could kerf my tail block since I'm trying to go with the inverted bottom. I'd be interested in any info or opinions.
Author:  SteveSmith [ Tue Jan 14, 2014 9:04 pm ]
Post subject:  Re: Triple florentine cut away help
I would just put the blocks in the corners - don't see any reason to put one in the center unless you want an endpin then I would just fit it.
Author:  Duhjoker [ Wed Jan 15, 2014 3:19 am ]
Post subject:  Re: Triple florentine cut away help
Sounds good to me just wanted to make sure it doesn't mess with the intonation or anything.
Author:  Duhjoker [ Wed Jan 15, 2014 10:45 pm ]
Post subject:  Re: Triple florentine cut away help
Image

Got it all bound together and sanded.
Author:  MikeyV [ Thu Jan 16, 2014 12:06 pm ]
Post subject:  Re: Triple florentine cut away help
That looks good. I'd concur with the posts above, no real need for a tailblock. You could always put a small one in there, for a bit if gluing area/stability, and/or an end pin.

Nice work! I look forward to more build pics.

Mike
Author:  Duhjoker [ Thu Jan 16, 2014 7:03 pm ]
Post subject:  Re: Triple florentine cut away help
Thanks. I want to say that I'm using mahogany this time for my back and sides. On a scale of 1 to 10 for ease of bending and retaining its shape after drying. It's a definite 10. Perfect wood for a beginner or if your doing weird or tight bends. The last wood I used which I determined to be Brazilian Cherry was really hard to bend and needed lots of soaking and clamping to retain its shape. It split a lot two. I was fortunate that I was making a slimline because I had to choose two from four pieces.
Author:  Duhjoker [ Thu Jan 16, 2014 7:28 pm ]
Post subject:  Re: Triple florentine cut away help
All right been working the kerfing all day then plane sanding and getting it ready to start working the top. I'm not gonna in-let the bracing. I didn't the last time and it turned all right. Also going with the flat top as far as the engineering goes. It worked in the past and should work again. And what I noticed on my last two soundboards and back board they kinda bow, I know in the opposite direction than a radius dish, but when the back and front are joined to the sides it creates a tight drum. When I start making full size guitars I'll change that method but for now I'm gonna go with what I know.

Here's a pic all kerfed up.
Image
Author:  Duhjoker [ Thu Jan 16, 2014 9:58 pm ]
Post subject:  Re: Triple florentine cut away help
Got my soundboard bracing all mapped out. I thought with the cut outs at the top and the one at the bottom that I would have to move some stuff around to get it to fit right but it's all goooood.

Image
Author:  whiskywill [ Fri Jan 17, 2014 10:21 am ]
Post subject:  Re: Triple florentine cut away help
Has the right hand side cracked at the waist?
Author:  Duhjoker [ Sat Jan 18, 2014 8:56 pm ]
Post subject:  Re: Triple florentine cut away help
Ok so I glued my lower tone bars, side tone bars and cut out support braces last night and I been carving them today. Let me say owwwwww. I start the process using a chisel so I get the beginning shape then I finish up with a trapazoid shaped razor blade wrapped in tape to pad it but it still hurts like hell. I need some kinda spring steel razor that's long and can be bent for tight areas. I tried to use a breakaway but it kept doing its job and that wasn't any help. What do you guys use to help refine your bracing curves? Besides sand paper or files that's a given for finishing after shaping.
Author:  johnparchem [ Sat Jan 18, 2014 10:31 pm ]
Post subject:  Re: Triple florentine cut away help
Duhjoker wrote:

... I need some kinda spring steel razor that's long and can be bent for tight areas.

What do you guys use to help refine your bracing curves? Besides sand paper or files that's a given for finishing after shaping.


A sharpened cabinet scrapper fits your spring steel razor description.

I use bevel edge chisels I did round the edge of the bevel a bit. The trick is to start to chisel where you want a low spot and take off a bit of the wood in the direction of desired high to low usually to the end of the brace. Move the chisel a little bit toward the high part of the curve and take another slice all the way to the end or to the end of the low area. Move the chisel a bit more toward the peak and take another full slice as described above. Continue until you get to where you peak should be. So what is happening is the lowest area will be cut every slice. as you move toward the peak the brace will have fewer and fewer slices taken from it. The very peak has no slices. Thus a curve. You can even do this if you are making a curve that dips and rises by starting from the center of the low area like in the picture. The next thing I would do is to start in the center again moving toward the other peak. By spacing the distance you move the chisel each slice you can change the slope of the curve.


Image
Author:  Duhjoker [ Mon Jan 20, 2014 2:51 am ]
Post subject:  Re: Triple florentine cut away help
Yes sir I do use a beveled chisel like the one your pic but I had never thought of turning it upside down. Which did help me get a better curve to begin with. But I like to finish with my razor so I can shave it better and remove smaller chunks. Thank you on the cabinet scraper, that looks like it would be perfect. I literally taped my finger tips on my index fingers to pad them a lil today. Also I forgot to consider that I was using Sitka spruce which is quite a bit denser than the western red cedar I used on my last two sound boards. I had no problem carving them at all. Thank you for your posts they were very helpful.
Author:  PeterF [ Mon Jan 20, 2014 4:57 pm ]
Post subject:  Re: Triple florentine cut away help
Sorry I know you've already braced it, but to me that lower bout shape is just asking for lower fan bracing rather than the two tone bars... When planning brace layouts, try to visualise the forces acting on the top and where the paths of stress will be. You want the forces to be dissipated across the whole top and usually it's best to divide the top into roughly equal looking areas with the braces.
I would use maybe 3 fan braces lapping the bridge plate or a lower x or double x...

Sent from my GT-S5830 using Tapatalk 2
Author:  Duhjoker [ Mon Jan 20, 2014 5:29 pm ]
Post subject:  Re: Triple florentine cut away help
It's cool. Prolly should have asked before hand whether to do modern or fan bracing. I would try to remove them but I already had to remove a piece of too wide bridge patch at the bottom and I had to repair the top afterward. That titebond 3 I'm using for this build is some tough stuff!!! Maybe I could thin them down a lil. Also I am trying to make the soundboard a lil stiffer than a regular steel string. So maybe it'll be ok. I don't know I learn more every time I do this. Thank you very much though for telling me.
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