swngdncr Posted January 2, 2016 Posted January 2, 2016 Hello, I am restoring my mothers LG1 which my brother started to tear apart and rebuild some odd 40 years ago. Unfortunately, he did not keep the top, which I gather came off in pieces. So, I need to figure out where to put the bridge on the new top I am making. I've read that the scale length is 24.75". However the 12th fret is at 12 5/16". I don't know what the compensation would be. I've had on person measure an 65 LG1, and tell me that the measurement to back center of the bridge is exactly 24.75". I saw a someone with a similar question on this board, but they had the old top, and it appears that put it back in the original location. I don't have the old top. Would appreciate any advice, or if you have an LG1 and can take some measurements for me.. it would be helpful. Thanks -cjr-
jedzep Posted January 2, 2016 Posted January 2, 2016 Good luck. You'll get good reference info from a lot of guys here. I suggest that you copy Gibson's X-braced pattern when installing to the new top, rather than the ladder brace found in the LG-1 specs. You'll get superior balance and bass response compared to the ladder config. I know many here love their LG-1's, but I'll bad-mouth that ladder-brace idea all day long.
swngdncr Posted January 2, 2016 Author Posted January 2, 2016 Thanks Jed,already planned on that. I found some very detailed plans for a 1940 L0 with the X-bracing all laid out, tracing it on to the top now. These plans have the 12th fret exactly where it is on My LG1, and the distance to the back of the saddle at the middle is exactly 24.75... I'm thinking that is what it is going to be, but would be nice to have some confirmation on that....-cjr- Good luck. You'll get good reference info from a lot of guys here. I suggest that you copy Gibson's X-braced pattern when installing to the new top, rather than the ladder brace found in the LG-1 specs. You'll get superior balance and bass response compared to the ladder config. I know many here love their LG-1's, but I'll bad-mouth that ladder-brace idea all day long.
jedzep Posted January 3, 2016 Posted January 3, 2016 If you do that, you will then own an LG2. Exact body size, just dif bracing, but the L0 has different body dimensions which will make for interesting results. Let us know, hopefully with photos, how it goes along.
j45nick Posted January 4, 2016 Posted January 4, 2016 Not sure if this will help or not, but here are some measurements for you, from three different Gibson flat-tops of mine. These measurements are made from the center of the 12th fret to the center of the saddle on the bridge. Measurements are made to the nearest 1/32" only, which results in some slight rounding errors. All three guitars have a nominal 24.75" scale length. All have traditional slot-through bone saddles that are nominally 1/8" wide. Each of the guitars has different kinds of frets, which can make precise comparisons inexact. None of the measurements includes any local saddle intonation, although with only 1/8" in width, variances of that kind are minimal. Finally, each guitar has different pin spacing at the bridge, from 2 1/8" on the J-45, to 2 3/8" on the L-OO. Measurements are made along the low E string, at the center of the fretboard and saddle, and along the high E string. The three guitars are: 1) 1948 J-45 (new bridge and saddle by Ross Teigen in 2010) 2) 1943 SJ re-issue (special run for Fuller's Vintage Guitars, with Luthier's Choice neck) 3) 1937 L-OO Legend (exactly replica of Parnell's 1937 L-OO) 1) 12 14/32", 12 12/32", 12 11/32" 2) 12 17/32", 12 15/32", 12 14/32" 3) 12 16/32", 12 14/32", 12 12/32" As you can see, for a nominal 24.75" scale length, there is a fair amount of variance in these measurements. This is pretty consistent with everything I've read, where the nominal 24.75" scale length has varied from about 24.625" to 24.875" over the years. Also, of course, the measurements from the nut to the 12" fret may vary slightly as well, in part due to varying amounts of intonation adjustment at the nut. I haven't adjust the intonation on any of the guitars, so the nuts are basically "as-delivered", as are the saddles. The only guitar that has exactly a 24.75" scale length is the one where Ross Teigen fabricated and installed a completely new bridge for me (replicating the original 1948 bridge).
swngdncr Posted January 5, 2016 Author Posted January 5, 2016 Thanks for the information... it is helpful to the extent that it is clear that there is variance among these different models, and just because one appears the same as the next, it isn't necessarily so.. but I'm still left with the conundrum of where to place the bridge. Maybe I'll try emailing Gibson, I wonder if they have that kind of info in their archives. If not, and I can't get more info, perhaps I'm just going to have to build it up, place the bridge, string it up, test it, and remove and relocate the bridge if I need to. Don't know what else I can do...-cjr- --------------------------- Not sure if this will help or not, but here are some measurements for you, from three different Gibson flat-tops of mine. These measurements are made from the center of the 12th fret to the center of the saddle on the bridge. Measurements are made to the nearest 1/32" only, which results in some slight rounding errors. All three guitars have a nominal 24.75" scale length. All have traditional slot-through bone saddles that are nominally 1/8" wide. Each of the guitars has different kinds of frets, which can make precise comparisons inexact. None of the measurements includes any local saddle intonation, although with only 1/8" in width, variances of that kind are minimal. Finally, each guitar has different pin spacing at the bridge, from 2 1/8" on the J-45, to 2 3/8" on the L-OO. Measurements are made along the low E string, at the center of the fretboard and saddle, and along the high E string. The three guitars are: 1) 1948 J-45 (new bridge and saddle by Ross Teigen in 2010) 2) 1943 SJ re-issue (special run for Fuller's Vintage Guitars, with Luthier's Choice neck) 3) 1937 L-OO Legend (exactly replica of Parnell's 1937 L-OO) 1) 12 14/32", 12 12/32", 12 11/32" 2) 12 17/32", 12 15/32", 12 14/32" 3) 12 16/32", 12 14/32", 12 12/32" As you can see, for a nominal 24.75" scale length, there is a fair amount of variance in these measurements. This is pretty consistent with everything I've read, where the nominal 24.75" scale length has varied from about 24.625" to 24.875" over the years. Also, of course, the measurements from the nut to the 12" fret may vary slightly as well, in part due to varying amounts of intonation adjustment at the nut. I haven't adjust the intonation on any of the guitars, so the nuts are basically "as-delivered", as are the saddles. The only guitar that has exactly a 24.75" scale length is the one where Ross Teigen fabricated and installed a completely new bridge for me (replicating the original 1948 bridge).
j45nick Posted January 6, 2016 Posted January 6, 2016 Thanks for the information... it is helpful to the extent that it is clear that there is variance among these different models, and just because one appears the same as the next, it isn't necessarily so.. but I'm still left with the conundrum of where to place the bridge. Maybe I'll try emailing Gibson, I wonder if they have that kind of info in their archives. If not, and I can't get more info, perhaps I'm just going to have to build it up, place the bridge, string it up, test it, and remove and relocate the bridge if I need to. Don't know what else I can do...-cjr- --------------------------- You're over-complicating this. The link below will take you to a discussion on scale length and saddle (and bridge) placement that should point you in the right direction. Gibson is not going to be of any help on this. You could benefit from buying a set of the full-size J-45 plans available from Stewmac. These show the bridge/saddle placement on the J-45, with the same nominal scale length as your LG-1. It's the saddle that drives this, not the bridge. Based on the Stewmac discussion that you can link to below, the center of the saddle (the transverse center) should be slightly over 24.75" from the center of the nut, if the distance from the nut to the center of the 12th fret is 12 3/8", which would be a "true" 24.75" scale. If your scale length is slightly less (based on the measurement from the nut to the center of the 12th fret being 12 5/16" on your LG-1), you can adjust that saddle/bridge location accordingly. stewmac on Gibson scale length Edit: going back and re-reading your earlier comments, if you place the bridge so that the center of the saddle is exactly 24.75" from the forward face (fretboard side) of the nut, you are probably going to be as close to right as you can get on this guitar. Perfect intonation is a moving target. With the relatively thin (1/8" thick) saddle of a slot-through Gibson bridge, you will never get there, no matter how carefully you place the bridge.
swngdncr Posted January 6, 2016 Author Posted January 6, 2016 Thanks J45.... I'll look at that reference material later tonight. I always appreciate links to relevant conversations/threads/etc.. -cjr-
j45nick Posted January 6, 2016 Posted January 6, 2016 Thanks J45.... I'll look at that reference material later tonight. I always appreciate links to relevant conversations/threads/etc.. -cjr- Here's a link that does all the hard work for you. If you enter the actual scale length--which would be 24.625" if the distance from the nut to the center of your 12th fret is 12 5/16"--it not only tell you what the fret spacing should be, but where the saddle and bridge should be positioned, using the two E strings as the reference. Elsewhere, on a previous link I sent you, I believe Dan Erlewine suggests a slight buffer at the saddle (slightly further away from the nut). The calculator in the link give the actual saddle position based on the mathematical formula. Anyhow, with the links I've sent you, you should be able to place it as well as anybody could. Are you re-using the original bridge, or starting from scratch? Stewmac doesn't carry Gibson-style belly bridges (belly up), I believe: only Martin style (belly down). fret/bridge calculator
j45nick Posted January 6, 2016 Posted January 6, 2016 About halfway through this video, they show you how the bridge placement is done at the factory, using a special jig.
swngdncr Posted January 7, 2016 Author Posted January 7, 2016 Thanks, interesting video... that is quite a jig... also interesting to see how the remove the finish before attaching the bridge.. -cjr- About halfway through this video, they show you how the bridge placement is done at the factory, using a special jig.
j45nick Posted January 7, 2016 Posted January 7, 2016 Thanks, interesting video... that is quite a jig... also interesting to see how the remove the finish before attaching the bridge.. -cjr- The important thing here is that they don't do the final positioning of the bridge until both the body (including the finished top) and the neck are joined together and completed. It's the only way to guarantee proper placement of the bridge. You may not have Gibson's fancy jig, but you can do an equally accurate job of placement with a lot of patience. You may find it helpful to align everything using low-tack masking tape on the top, and drawing all your reference lines on that while finalizing the bridge placement. Incidentally, I haven't done this particular job before, but I make a lot of jig fixtures for similarly-critical woodworking installations.
swngdncr Posted January 9, 2016 Author Posted January 9, 2016 Thanks again, yeah, we've done a bit of jig building over the years for a plethora of projects, I think I'll be able to figure something out.
swngdncr Posted January 26, 2016 Author Posted January 26, 2016 Update... with the help of the folks here and other information I think I have the scale length figured out, at least as best I can. Here is an update and some photos. I have the top cut, the soundhole cut and the purfing around the soundhole done, at least as close as I could get to the original style. I'm trying now to decide what to do with the bracing. I'm thinking I'd like to do some scalloping to the braces. I haven't played much guitar since I was a kid, and even then I didn't play much. But, I've picked it back up again and playing moms old classical guitar. I like a full, sort of deep rich sound. I think I read that some of the earlier Gibson's were scalloped.. and since this isn't going to be original anyway... I did devise a method of bracing the interior while I put the top on. Using the turnbuckles, I'll be able to reach in the hole and unscrew them and pull them out after I attach the top. So, that is where things stand, researching the scalloped bracing idea now.
j45nick Posted January 26, 2016 Posted January 26, 2016 Update... with the help of the folks here and other information I think I have the scale length figured out, at least as best I can. Here is an update and some photos. I have the top cut, the soundhole cut and the purfing around the soundhole done, at least as close as I could get to the original style. I'm trying now to decide what to do with the bracing. I'm thinking I'd like to do some scalloping to the braces. I haven't played much guitar since I was a kid, and even then I didn't play much. But, I've picked it back up again and playing moms old classical guitar. I like a full, sort of deep rich sound. I think I read that some of the earlier Gibson's were scalloped.. and since this isn't going to be original anyway... I did devise a method of bracing the interior while I put the top on. Using the turnbuckles, I'll be able to reach in the hole and unscrew them and pull them out after I attach the top. So, that is where things stand, researching the scalloped bracing idea now. I would scallop them in the middle and at the ends. You can probably find some video on that. The two short braces next to the soundhole are normally laid on their sides, like popsicle sticks. They are primarily to prevent local splitting around the soundhole, I believe. What material is that bridgeplate? This would normally be a 1/8" thick piece of solid maple.
swngdncr Posted January 26, 2016 Author Posted January 26, 2016 Thanks... I found lots of images, and different ways of scalloping, but didn't look at videos, so I'll take a look for vids. The bridgeplate is rosewood. I read somewhere to use hardwood and also rosewood being used and I had a nice piece already planed. Looking back at the 1940 lg0 plans, i thought they were vertical, looking again,I'm not so sure it isn't really clear on the soundhole braces. But looking at images,most are flat. I can change this... I would scallop them in the middle and at the ends. You can probably find some video on that. The two short braces next to the soundhole are normally laid on their sides, like popsicle sticks. They are primarily to prevent local splitting around the soundhole, I believe. What material is that bridgeplate? This would normally be a 1/8" thick piece of solid maple.
swngdncr Posted January 26, 2016 Author Posted January 26, 2016 Thanks... I found lots of images, and different ways of scalloping, but didn't look at videos, so I'll take a look for vids. The bridgeplate is rosewood. I read somewhere to use hardwood and also rosewood being used and I had a nice piece already planed. Looking back at the 1940 lg0 plans, i thought they were vertical, looking again,I'm not so sure it isn't really clear on the soundhole braces. But looking at images,most are flat. I can change this... I would scallop them in the middle and at the ends. You can probably find some video on that. The two short braces next to the soundhole are normally laid on their sides, like popsicle sticks. They are primarily to prevent local splitting around the soundhole, I believe. What material is that bridgeplate? This would normally be a 1/8" thick piece of solid maple.
j45nick Posted January 27, 2016 Posted January 27, 2016 Thanks... I found lots of images, and different ways of scalloping, but didn't look at videos, so I'll take a look for vids. The bridgeplate is rosewood. I read somewhere to use hardwood and also rosewood being used and I had a nice piece already planed. Looking back at the 1940 lg0 plans, i thought they were vertical, looking again,I'm not so sure it isn't really clear on the soundhole braces. But looking at images,most are flat. I can change this... The soundhole braces are vertical on my L-OO Legend, but are laid flat on all my other Martin and Gibson flat tops. They're just 1/8" thick where they are laid flat, but are the thickness of the other top braces behind the soundhole on the L-OO. Rosewood is OK for a bridgeplate, but most people say maple is a bit better at transmitting sound, and is probably a bit more resistant to damage from the ball ends of strings. Whatever you use, you want to make sure it is fully bonded to the top with the thinnest layer of glue you can effectively use. You want a rock-hard joint between the bridgeplate and the top for the best sound transmission. That bridgeplate wants to be thin, too. 1/8" (3mm) is ideal. Photo images of scalloped bracing should be adequate for the job. Modern Gibson bracing is a very good guide, as Ren Ferguson is a master at bracing design.
aliasphobias Posted January 27, 2016 Posted January 27, 2016 I had a Guild D40 ('72 me thinks) w/rosewood plate sounded fantastic. Good suggestion to keep the hide glue thin here. I admire your endeavor.
swngdncr Posted January 27, 2016 Author Posted January 27, 2016 Thanks for the comments and information. I want to try and check in here with updates, so that the next guy/gal who goes traveling down this path has the information. I'm always so excited when I see I've had a reply! I've been getting advice from the fine folks at Frets.com too... They are recommending removing the neck, which I really wanted to avoid, but I'm not sure I can get the top on with the braces in place without removing the neck, so I may not have a choice. We'll see after I've shaped the braces... -cjr-
aliasphobias Posted January 27, 2016 Posted January 27, 2016 I agree with neck removal. I assumed it was already loose and just set in place. Off to the Goodwill to look for an espresso maker .
j45nick Posted January 27, 2016 Posted January 27, 2016 Thanks for the comments and information. I want to try and check in here with updates, so that the next guy/gal who goes traveling down this path has the information. I'm always so excited when I see I've had a reply! I've been getting advice from the fine folks at Frets.com too... They are recommending removing the neck, which I really wanted to avoid, but I'm not sure I can get the top on with the braces in place without removing the neck, so I may not have a choice. We'll see after I've shaped the braces... -cjr- The body is always complete (including the top) before the neck goes on. It's the only way you can get the neck angle right. You may want to go back and follow the link I sent earlier to the series of videos showing how guitars are built at the Gibson plant There are something like a dozen of those videos showing the whole process.
swngdncr Posted January 27, 2016 Author Posted January 27, 2016 Thanks, yes I knew the neck is normally off, but I'm apprehensive, not about taking the neck off, but putting it back, so I was hoping I could slide the top on without removing the neck. THink this weekend's task will be removing the neck... -cjr-
j45nick Posted January 27, 2016 Posted January 27, 2016 Thanks, yes I knew the neck is normally off, but I'm apprehensive, not about taking the neck off, but putting it back, so I was hoping I could slide the top on without removing the neck. THink this weekend's task will be removing the neck... -cjr- Do a bit of research on this process, if you haven't already. The neck is a hide glue joint with the neckblock, and needs steam injection to loosen the joint, if the neck isn't already loose. I believe there are videos on stewmac.com, if you can't find them elsewhere. Judging from the way you have done the job so far, this shouldn't be too much of a stretch for you.
swngdncr Posted January 27, 2016 Author Posted January 27, 2016 Thanks, I've watched the videos already, and I think I can do it. I have a steam machine, I just need to rig it up to inject it into a little hole..I'll have to dig it out an see what I might need to do that... You know this is giving me the bug to build one from scratch. My brother gave me all this rosewood and sitka spruce that he got 40 years ago, and it is just begging to be made into a guitar.... But, one thing at time... ;-) -cjr- Do a bit of research on this process, if you haven't already. The neck is a hide glue joint with the neckblock, and needs steam injection to loosen the joint, if the neck isn't already loose. I believe there are videos on stewmac.com, if you can't find them elsewhere. Judging from the way you have done the job so far, this shouldn't be too much of a stretch for you.
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