Members gitnoob Posted July 13, 2011 Members Share Posted July 13, 2011 My guitar building class started this week. Like the uke class, it's a bit unstructured, but that suits me fine -- I thrive on uncertainty. So here are our choices: Body styles: Classical, Flamenco, 19th-century parlor, steel-string parlor, or steel-string "Bluesman." Top woods: Cedar, Engelmann spruce, Sitka Spruce Back/sides: Lacewood, Maple, Cypress, Rosewood We also will choose our scale length, nut width, fretboard/bridge material, binding, rosette, etc. So what am I going to build? A mutt! The body size and shape is based on a Romanillos classical guitar, roughly the size of a Martin 00. But it'll be steel string, and the bracing will be loosely based on a Martin 1-18. And here's the fun part. I'm going to Somogyify it. Somogyi is pretty secretive about his bracing, but somebody snapped this picture during a workshop. I tapped and did some deflection testing of the various wood choices, and I ended up picking the most traditional: Sitka Spruce and Indian Rosewood. The stiffness and tone of the woods varied pretty significantly. Lacewood came in second after Rosewood for the back, but there really was nothing comparable to Sitka for the top. Engelmann was considerably less stiff at the same thickness. I've joined the top, joined the back, and planed some bracing stock down to size, but now I need to flesh-out the design of my mutt.... Link to comment Share on other sites More sharing options...
Members poppytater Posted July 13, 2011 Members Share Posted July 13, 2011 Mutts are usually smarter Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 14, 2011 Members Share Posted July 14, 2011 Good luck, gitnoob. You've already gotten a bit done. Have you gotten the plates to a desirable thickness? That classical does look like a 00 but the upper bout seems to be wider. Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 14, 2011 Author Members Share Posted July 14, 2011 I think the Romanillos looks pretty similar to the Goodall parlor. Similar dimensions, too. I haven't thicknessed the top yet, but perhaps tomorrow. The luthier demonstrated thicknessing the top by hand plane today, and I think it'll be cool if I can do it. That way, I'll have the ability to thickness at home (for possible future builds) without needing a thickness sander. (Although he'll be doing the backs and sides via thickness sander since they're harder to plane.) Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 14, 2011 Author Members Share Posted July 14, 2011 I hand-thicknessed the top today. Quite a workout. I took it down to a little less than 3mm (about 0.11") and it's still pretty stiff. Somogyi would make it much thinner (about 2mm / 0.085") or until it readily bends longitudinally. I'm afraid to go that thin. I'll do final thicknessing once the top is on the box, and then the plan is to thin the plate as it goes toward the edge (i.e., thicker in the middle, thinner at the rim). And I think I have a workable bracing pattern. That Somogyi above is a dread, so I found a Bashkin (who studied voicing under Somogyi) 00 as a more appropriate model. So here's my current plan: Some of the principles include: A beefy upper-transverse brace that doesn't taper at the ends. This is the main load-bearing brace in a guitar -- purely structural, and it terminates the active area of the soundboard. Tall, thin soundhole reinforcement braces. Again, purely structural, and the Martin-style flat braces provide very little structural reinforcement. No popsicle brace. I don't understand why it's needed, so I'm leaving it out. Evenly distributed "tone bars" -- finger braces and lower face braces. If you want a predictable and even response, you don't want varying sized patches of free soundboard. Symmetrical tone bars. See above. I can't see any reason to use the Martin-style asymmetrical tone bar. A bridge plate that extends closer to the center of the X. The bridge activates the soundboard, and the X-bracing should be tightly coupled to the bridge. A stiffer area between the bridge and the X provides more leverage. A bridge plate that extends down into the lower bout with a similar curvature to the lower bout. Again, the bridge is the energy distribution device, and you want even distribution. The larger plate will help prevent bridge rotation down the road as well. A tapered bridge plate. Just as the bridge and other braces are tapered for a smooth transition to the soundboard, so will the bridge plate. Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 15, 2011 Author Members Share Posted July 15, 2011 I couldn't resist taking a picture of my guitar-to-be. Anybody notice anything different about the bridge/fretboard vs the back? Hint [video=youtube;_mQHr8bAojU]http://www.youtube.com/watch?v=_mQHr8bAojU Link to comment Share on other sites More sharing options...
Members poppytater Posted July 15, 2011 Members Share Posted July 15, 2011 You're havin' a ball with all this build stuff ain't ya? Good on you my friend. Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 15, 2011 Author Members Share Posted July 15, 2011 Yeah, it's sort of a combination of physics, engineering/design, model airplane building, working with exotic woods, hanging out with other weird folks, and a little bit of music. Link to comment Share on other sites More sharing options...
Members poppytater Posted July 15, 2011 Members Share Posted July 15, 2011 I'm glad you're having fun. Me, I prefer to think of guitars as magical boxes made by wizards in some enchanted land. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 15, 2011 Members Share Posted July 15, 2011 I don't get it. Is it pauduck? Nah - I see you got yourself some BRW there. Good for you. Whats the binding going to be? More maple to match the rosette? How about the back strip? As for hanging out with weird people I used to think that musicians and groupies were weird, but after talking to my friend John about his recent attendance at the Association of Stringed Instrument Artisans now I know that luthiers can be Out There too! In a good way of course! BTW, gitnoob, do you recognize this fella? Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 15, 2011 Author Members Share Posted July 15, 2011 Whats the binding going to be? More maple to match the rosette? How about the back strip? I hated working with the spalted maple. "Spalted" is just a euphemism for rotten and mold spore infested. Besides crumbling and emitting poisonous mold spores all over the place, it has density that varies from spongy to maple-hard. I found it impossible to cut or sand the stuff to get a straight edge. So I'm going to try again with Amboyna burl. If it works, maybe I'll try to get some orange/red color in the binding. For now, I'm deferring those decisions. While most builders pick a center strip for the back at join time, this luthier is happy to route a channel later. He says routing the channel also provides a better gluing surface than the join method. BTW, gitnoob, do you recognize this fella? Yeah, I recognize my hero in the pic. I think he used to be an English major, so he presents his material with some flair and eloquence. Some people think his guitars are pretty good too. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 16, 2011 Members Share Posted July 16, 2011 OK, I'm intrigued. In fact, I'm downright addicted. I need a fix. What's going on? Have you closed the box yet? FWIW I'm not a fan of the spalted stuff either. Are you committed to that reddish-orange stuff though? What about koa, snakewood, maple or even plain old mahogany? Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 16, 2011 Author Members Share Posted July 16, 2011 The class is Mon-Thu, so not a lot of progress the last couple of days. I cut out a rough guitar shape for the back and handed it off to the instructor so he could thin it on his thickness sander. Also handed him the bridge blank so he could slot it for me. I need to complete the rosette this weekend so I can continue working on the top, so I'm pretty committed to the Amboyna. Total PITA to work it as small segments like I did. Your idea of cutting a circle out would have been better, but I had fairly small chunks of wood to work with. I'm trying to book-match pieces and lay them out in a nice pattern, but it's basically like joining 6 tops -- lots of cutting, sanding, and fitting. Link to comment Share on other sites More sharing options...
Members bluzboy Posted July 16, 2011 Members Share Posted July 16, 2011 I hand-thicknessed the top today. Quite a workout. I took it down to a little less than 3mm (about 0.11") and it's still pretty stiff. Somogyi would make it much thinner (about 2mm / 0.085") or until it readily bends longitudinally. I'm afraid to go that thin. I'll do final thicknessing once the top is on the box, and then the plan is to thin the plate as it goes toward the edge (i.e., thicker in the middle, thinner at the rim). And I think I have a workable bracing pattern. That Somogyi above is a dread, so I found a Bashkin (who studied voicing under Somogyi) 00 as a more appropriate model. I'm intrigued by those small braces on the lower bout of the Bashkin by the bridgeplate (I suppose inspired by my recent experience with the Sigma). They seem to be floating. I've always assumed--wrongly, I guess--that they needed to be affixed to a larger brace. How do you plan on securing them? Would simply gluing them to the top suffice? Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 16, 2011 Author Members Share Posted July 16, 2011 I'm intrigued by those small braces on the lower bout of the Bashkin by the bridgeplate (I suppose inspired by my recent experience with the Sigma). They seem to be floating. I've always assumed--wrongly, I guess--that they needed to be affixed to a larger brace. How do you plan on securing them? Would simply gluing them to the top suffice? I'm still learning this stuff myself, but here's my understanding so far: Think of the top as vibrating in three ways: pumping up and down, rocking side to side, and rocking top to bottom. How you brace it determines how freely it can move in each of those three modes. The X is the main brace, and it supports all three modes. The thinner the ends of the X, the more the top can move in the up and down pump mode, which determines the bass response. So some builders stop short of the kerfed lining to free up the top. Others tuck the ends into the lining. The thickness of the tucked ends is important, but tucking will both stiffen the rim and help keep the braces on the top. For the most part, it's just the gluing to the top that keeps the braces there. Now, if you consider the X the main brace, it's then up to you to decide if you want the other braces to work in concert with the X or independent of the X. In the example above, the finger braces are tightly coupled to the X, so they'll rock the top especially in the side-to-side and top-to-bottom modes -- the higher frequency response. The lower face braces are uncoupled from the X, so they will be driven directly by the bridge. They are arranged to maximize side-to-side movement and they add stiffness mostly in the top-to-bottom mode. Similar to fan braces in classical guitars. Fun stuff, eh? Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 17, 2011 Author Members Share Posted July 17, 2011 In case you sadistic types want to see how I drive myself nuts, here's my rosette process: Cut up a bunch of tiny pieces of wood. Draw my soundhole on a piece of paper. Draw a couple of circles for potential rosette sizes. Fit the pieces together like a puzzle grain-pattern-wise. As I find grain-pattern fits I like, cut/sand the pieces so they physically fit together. (There can be no gaps -- hopefully the ones you see below will be sanded away soon.) Glue them together so they don't move. Wait an hour for the glue to dry. Tape them to the paper. Place a translucent mask over the whole mess to give me an idea of what the ring will look like. After this process is complete, I'll glue the paper to backer board, and then use a Dremel router to cut out the ring. You can buy pre-made wooden rosettes for like $8. At a reasonable labor rate, this one should cost me a couple grand.... Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 18, 2011 Author Members Share Posted July 18, 2011 Woohoo! Rosette Mission Complete. Link to comment Share on other sites More sharing options...
Members kwakatak Posted July 18, 2011 Members Share Posted July 18, 2011 Good work so far, but there's also the process of inlaying it into the top. You've got the uke's under your belt so maybe this won't be as hard for you as it was for me. If you're going to use purfling though it could get just a little complicated! ;-) Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 18, 2011 Author Members Share Posted July 18, 2011 My understanding is that the difficulty is with getting the channel to exactly match with the ring. Plan A is a perfect fit with the full ring. Plan B is to open up the top of the ring and then stretch or compress the rosette to get a better fit (and then cover the top of the ring with the fretboard). Plan C is to buy another Chinese guitar. FWIW, I'd like to try to do it without purfling, but I find that a lot of this building stuff means creative adaptation after a screw-up. Link to comment Share on other sites More sharing options...
Members bluzboy Posted July 18, 2011 Members Share Posted July 18, 2011 Lovely looking rosette! And thanks for the explanation about the braces. Can't say I actually grasp it, but I appreciate it nonetheless. Link to comment Share on other sites More sharing options...
Members knockwood Posted July 18, 2011 Members Share Posted July 18, 2011 Very, very nice rosette! Looks like it must have been a bitch to execute. Link to comment Share on other sites More sharing options...
Members Galabar Posted July 18, 2011 Members Share Posted July 18, 2011 Wow, very nice! Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 18, 2011 Author Members Share Posted July 18, 2011 Thanks for all the kind words about my wooden doughnut. One of my guitar build classmates makes art for a living. I'll try to take a picture of his rosette next week. Round soundhole. Square rosette. And thanks for the explanation about the braces. Bluz, your question has been burning a hole in my brain. I looked up the info about Bashkin's fan braces, and he apparently uses some sort of lap joint to couple those braces to the bridge plate. I'll see if I can do something similar. If nothing else, I think I may notch the bridge plate for those braces and then put a little spruce patch over each to ensure the whole contraption is tightly coupled. I think that big hunky bridge plate is the biggest risk I'm taking tone-wise. It'd be nice if it doesn't sound like crap. Link to comment Share on other sites More sharing options...
Members gitnoob Posted July 18, 2011 Author Members Share Posted July 18, 2011 there's also the process of inlaying it into the top. Did a couple of test runs on some scrap first. Once I found a good inner diameter, routed out the channel on the top. Then the outer diameter. Then took out the stuff in between. That got me a channel that was a pretty close fit, but not close enough. So then I sanded the ring, filed the edges of the channel a bit, test fit, broke the rosette about 4 times in the process, but finally got it to fit. Then glued it in. Used a rasp to bring down the height a bit. Then used an orbital sander to bring it down almost flush to the top. I'm pretty happy with the results. The grain pattern changed a bit as I sanded down the ring, so it's not quite as book-matched as when I started. Link to comment Share on other sites More sharing options...
Members bluzboy Posted July 18, 2011 Members Share Posted July 18, 2011 I'm pretty happy with the results. The grain pattern changed a bit as I sanded down the ring, so it's not quite as book-matched as when I started. Personally, I like a little asymmetry. And I think it looks even nicer than before; the grain really pops. Can't wait to see the end results! Link to comment Share on other sites More sharing options...
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