Members guitarcapo Posted August 10, 2014 Members Share Posted August 10, 2014 I'm keeping those options open. The plan right now is to install a soundboard transducer while the box is still open - others have suggested a magnetic pup that doesn't require cutting into the top. Better yet: Why not both? I have a Dimarzio pickup system in one of my flattop acoustics that actually BLENDS a magnetic soundhole pickup with a soundboard transducer. (The Angel Dual Source). It's also active using a 9V battery. I replaced the stock undersaddle transducer in the system with a soundboard transducer. It might be easy to modify that system to work with a magnetic pick guard mounted pickup and soundboard transducer without cutting into the wood anywhere or effecting the function or appearance of the guitar as an acoustic archtop. Run the magnetic wiring under the pick guard and into the F-hole. All of the rest of the elements are inside the guitar and the output exits via the single endpin jack. One snag might be the battery mounted inside the guitar. That might have to be mounted under the pick guard because it might be difficult dealing with it through the f-holes. With MY guitar (a Harmony Sovereign 1266) I found that I was blending out the soundboard transducer for the magnetic more when I was playing. Less like a natural woody sound but I liked the jazzy tone of that magnetic pickup. A little of the soundboard transducer is nice to blend in if you like those crispy woody higher partials. Too much makes the tone sound a little "boxy"... and of course and body contact with the wood gets amplified more. A less complicated system would just be to install the two independent pickups with a stereo jack or two separate jacks. Blend them at the amp(s) somehow or with a stereo pedal. The soundboard transducer will usually be a weaker signal than the magnetic pickup without an onboard pre-amp, though. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 10, 2014 Author Members Share Posted August 10, 2014 The one thing you forget is that Jesse says he'll never plug this in. If you go back to the very beginning, it is supposed to be an acoustic guitar that looks like an electric. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 11, 2014 Members Share Posted August 11, 2014 Maybe just a soundboard transducer to the endpin jack, then. LOL. Link to comment Share on other sites More sharing options...
Members Grant Harding Posted August 12, 2014 Members Share Posted August 12, 2014 The customer isn't always right, but they're ALWAYS the customer. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 12, 2014 Author Members Share Posted August 12, 2014 Ain't that the truth. Lets get back to building. This isn't all that impressive but its sure a lot of fun. I have a tendency to really overbrace things, then try to bring them back to that magic line of just enough. Backs I usually leave overbraced a bit - in this case I really want to hold that dome so the braces are a bit bigger than usual. But they do need to be carved down a little The plane was my grand daddy's, the chisel my dad's. Neither was really a wood worker but they had decent tools and they came down to me. I've taken a little time to sharpen them and its really a pleasure to work with them. I do have some newer tools but I always seem to reach for these. Here's the back at a good stopping point - does anyone need wood chips for their hamster cage? Tomorrow we'll bend the sides Link to comment Share on other sites More sharing options...
Members guitarcapo Posted August 12, 2014 Members Share Posted August 12, 2014 Not to detract but I just thought this archtop was uber cool: And believe it or not...a Harmony Cremona! Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 12, 2014 Author Members Share Posted August 12, 2014 Its tomorrow, so it must be time to bend. If you remember back to when I built the mold, there was also the innies, which I glued to a few little spacer blocks to look like this This is not a medieval torture device or something to make wine, but rather my Fox side bender with the innie thingie in position. Surrounding it are the timer and heat controller for the heating blanket and some odds and ends for bending. So the procedure is to thin the side pieces to about 0.075 or 0.080 and cut them to the basic shape of the side. Dampen them with water and put them between two metal slats, then on the outside I put an industrial heating blanket. But this whole sandwich into the torture device, er, bender and turn on the heat. When it reaches about 250 F I pull the little gizmos attached by the springs to bend the upper and lower bout, then when its at about 300 F start cranking down the waist. Let it come up to 350 and cook for 5 or 10 minutes, then turn it off and let it cool Then take the sides out and clamp them into the mold. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 12, 2014 Author Members Share Posted August 12, 2014 SHE-IT. Sorry, please cover the ears of any small children who might be reading this forum. The first side bent beautifully, but the second If FretFiend were here right now he would know exactly what to say. Oh well... The one consolation is that when I took a seminar with Charles Fox (the inventor of the bending machine) he too broke a side while trying to bend a cutaway. He shrugged and said "stuff happens". I've learned a long time ago that when this kind of stuff happens I'm best to lock the shop and go do something else. Going climbing tomorrow - I be back Link to comment Share on other sites More sharing options...
Members kwakatak Posted August 13, 2014 Members Share Posted August 13, 2014 Them's the breaks, Freeman. FWIW I feel your pain because I've done it myself. You've already got a good track record doing this but I wonder if maybe you thinned it too much and didn't cook it enough? On my hog build I thinned it to .085" and cooked it to 300 before bending the bouts. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 15, 2014 Author Members Share Posted August 15, 2014 I'm a bit surprised that my last post didn't get more of a response. Either nobody (besides Cornelius) is reading this thread or it's "ho, hum, Keller just broke his guitar..." Whatever, I've had a good rest and am going to carry on. To answer Cornelius's question, the reason that it broke is that this wood is fairly figured and figured wood is more prone to breaking. The thing that makes the "figure" in the first place is that the grain is kind of waving back and forth and when you cut pieces for sides or backs you cut across the grain lines. It simply is much weaker. It probably wasn't thin enough - I mic'ed it at 0.085 and think is should have been closer to 0.075. Anyway, it broke, what to do now. There are two choices - I've got more mahogany and could just bend another set of sides. The wood doesn't have the figure and wouldn't match the back but that shouldn't matter with mahogany. However, before we do that lets see if we can't save these. If I move the point of the horn back about an inch and relax the curve I can fit it inside the unbroken part. I had to make a new form for the inside of the horn, shown here with the broken piece of the side. Break out the old hot pipe. This is how I used to bend sides before I got the Fox machine and many people still do it this way. Its just a little propane torch inside a capped off piece of 2 inch pipe - I put a damp rag on the pipe and work the wood back and forth on it until it softens and can be bent Once the wood is pliable I clamp it in the mold Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 15, 2014 Author Members Share Posted August 15, 2014 Well, that didn't work - the wood cracked again so I tried with another piece of mahogany - this time with nice straight grain (I figured that being on the inside of the horn no one would notice, besides that's the only choice I have). This time I used my heat blanket instead of the hot pipe The piece came out good and I fit it into the rim. There is a lot going on here and unfortunately I didn't take pictures of all of the steps There is a wedge shape block that forms the point of the horn and the part that fits against the neck block has to be exactly the correct width - that will flow into the neck heel and needs to be exactly one half of the width of the neck at the 14th fret. I fiddled with this a lot before gluing up - but forgot the camera laying on the work bench. Here is the rim with the clamps off laying on the original ES-175 plans showing the change in shape of the cutaway. In a way I like it more than the really sharp pointed horn (my wife said its "not as horny". I e-mailed that picture to Jesse with a brief explanation for his approval and he said it was OK. Whew Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 15, 2014 Author Members Share Posted August 15, 2014 Next thing to do is glue in the kerfing. "Kerf" is the term for the cut of a saw blade, "kerfing" is a strip of wood with a whole lot of little saw blade cuts - it is nice and flexible and bends around the rim to provide a gluing surface. I buy kerfing all ready made - it would be a real hassle to set up a saw to make it. Those are special kerfing clamps available at lutherie supply houses and they are very expensive. Last step here is to glue in some little mahogany side braces that run across the grain. As prone as this wood is to splitting I don't want to take any chances I think the sides will be just fine and I'm feeling better about everything now. Link to comment Share on other sites More sharing options...
Members Preacher Posted August 15, 2014 Members Share Posted August 15, 2014 I think the sides will be just fine and I'm feeling better about everything now. Freeman, glad to see things back on track after that setback - and then another. I've enjoyed your explanations and seeing your different methods for bending the sides - especially the hot pipe. Looking great! Link to comment Share on other sites More sharing options...
Members newbuilder Posted August 16, 2014 Members Share Posted August 16, 2014 Wow, this is a great build thread! Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 16, 2014 Author Members Share Posted August 16, 2014 Thanks Newbuilder. Hope your handle means that you build too - one of the reasons I like to post build threads is to inspire others to try their hand at it. Next part is just tedious - sanding the rim perfectly flat and then putting a little angle in it to match the curve of the top and back. I've got two sanding blocks - one big and flat, the other curved at 16 foot radius And I just keep working my way around the rim Some people put sandpaper in their radius dish with double sticky tape - I never had good luck with that but this seems to work Check it as I go with a "straight edge" with the 16 foot radius. I drew this with AutoCAD with 16 foot on one side and 25 on the other (normal top dome for an acoustic) and cut it out on a laser cutter - I miss the machine shop where I used to work... Link to comment Share on other sites More sharing options...
Members gardo Posted August 17, 2014 Members Share Posted August 17, 2014 I may not be commenting on every post but you can be certain I'm enjoying every one of themThanks for the education it's great Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 17, 2014 Author Members Share Posted August 17, 2014 I may not be commenting on every post but you can be certain I'm enjoying every one of them Thanks for the education it's great That makes it all worth while Link to comment Share on other sites More sharing options...
Members kwakatak Posted August 17, 2014 Members Share Posted August 17, 2014 Looking good. I love this phase of the build; it's starting to look like a substantial structure and not just a bunch of bent pieces of wood. Could you forward on the specs for your pipe bender? I'm interested in messing about with that kind of stuff - while it's still warm enough outside to do so without risk of burning my house down! ;-) Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 18, 2014 Author Members Share Posted August 18, 2014 Looking good. I love this phase of the build; it's starting to look like a substantial structure and not just a bunch of bent pieces of wood. Could you forward on the specs for your pipe bender? I'm interested in messing about with that kind of stuff - while it's still warm enough outside to do so without risk of burning my house down! ;-) Hard to believe that in, what, three weeks, we've come from to here The hot pipe is very simple - its a 6 inch long 2 inch pipe nipple with a cap from Lowes or Home Depot. A couple of 2 inch U brackets hold it to a piece of angle iron which I clamp to my work bench. The torch is something you would use to sweat solder copper water pipe. LMI sells practice scrape, you can also use cut off pieces from anything you are working on - I can't stress the importance of practice to get a feeling for when the wood wants to bend. I did a couple of sides this way then decide it was time to buy the Fox machine. I tend to do a lot of fiddling around at this stage of the build - maybe I know that once the lid goes on the box it is the end of the chapter. I won't show pictures of sanding braces and tapping the top and drinking coffee and all the important lutherie things that go on here, but one thing is important. The brace don't just end at the sides, they are let into little pockets in the kerfing. I learned that the simplest method of doing this is to make all the braces the same height at their ends - say the thickness of this piece of plastic binding Here is the same thing for the back (now jumping ahead to the next frame since I can only do four pictures per posting) Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 18, 2014 Author Members Share Posted August 18, 2014 Now put the Dremel tool on its little router base and set the depth of the cut to the thickness of that piece of binding mark and route out the little pockets Do a little more tapping and fiddling and sanding and coffee drinking - finally its time to sign the top and pop it into the oven Link to comment Share on other sites More sharing options...
Members gardo Posted August 18, 2014 Members Share Posted August 18, 2014 Aren't tools great !Having the right tool for the job makes all the difference . Link to comment Share on other sites More sharing options...
Members Grant Harding Posted August 18, 2014 Members Share Posted August 18, 2014 Awesome as usual Freeman. You should never worry whether people are following these threads or not. Even if I'm not posting constantly I come back here specifically for these threads. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted August 18, 2014 Author Members Share Posted August 18, 2014 Aren't tools great ! Having the right tool for the job makes all the difference . TAS is even worse than GAS. "Honey, can I have a new router?" Link to comment Share on other sites More sharing options...
Members Preacher Posted August 18, 2014 Members Share Posted August 18, 2014 Awesome as usual Freeman. You should never worry whether people are following these threads or not. Even if I'm not posting constantly I come back here specifically for these threads. Yes, very much this. It's especially evident when you check the view count of this thread against the others. Link to comment Share on other sites More sharing options...
Members t_e_l_e Posted August 19, 2014 Members Share Posted August 19, 2014 can't wait to see the finished guitar, as always great thread FKthx for sharing Link to comment Share on other sites More sharing options...
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