dry pond wood works Posted February 13, 2008 Report Posted February 13, 2008 I am totally new to this, but I am an experience woodworker and boatbuilder. My son wants to build a solid body elec. guitar, so I have begun reading up...already I have some questions. --I noticed that people tend to taper the fretboard then using a centerline, cut the fret kerfs. Wouldn't it be easier to cut the fret kerfs while the board is still square and then just taper it? I noticed that Stewmac sells a small table saw blade for cutting the slots, so I would assume that someone is doing it this way. --With regard to necks, has anyone ever just laminated a neck with horizontal veneers and just laminated the curve of the "machine head" right into the neck as one piece instead of glueing it on later? I have access to a vacuume press and we do this kind of thing all the time. It would be very strong and would probably look cool as well. I was even thinking of putting a layer of unidirectional carbon fiber between some of the outer laminations to give it real ridigity against the strings...like a built in truss rod. As I said, I am new to this whole thing so maybe this has all been done. I love the web sitel Allan Quote
madawgony Posted February 13, 2008 Report Posted February 13, 2008 --I noticed that people tend to taper the fretboard then using a centerline, cut the fret kerfs. Wouldn't it be easier to cut the fret kerfs while the board is still square and then just taper it? I noticed that Stewmac sells a small table saw blade for cutting the slots, so I would assume that someone is doing it this way. For my set up and the tools I have available, I find that slotting the fretboard while it is still square works well. You do have to be careful when you do "cut" the fingerboard down to the final size that you avoid tear-out. All those fret kerfs present a lot of chances for tear-out. I cut my fingerboard oversized, leaving it square. I then radius the board followed by cutting the kerfs (using a table saw and the thin-kerfed blade). Quote
dry pond wood works Posted February 13, 2008 Author Report Posted February 13, 2008 Thanks for your response. I would have thought that you would kerf it on the table saw THEN radius it. If you radius it first, how do you keep it level when you pass it throug the table saw? Also, when I see these tables that give distances from the nut to the frets, the dimensions are to 3 decimals. Is that really practical? You can't measure and cut in a typical woodshop to 1/1000th of an inch. How far do you really take it? Quote
fryovanni Posted February 13, 2008 Report Posted February 13, 2008 Thanks for your response. I would have thought that you would kerf it on the table saw THEN radius it. If you radius it first, how do you keep it level when you pass it throug the table saw? Also, when I see these tables that give distances from the nut to the frets, the dimensions are to 3 decimals. Is that really practical? You can't measure and cut in a typical woodshop to 1/1000th of an inch. How far do you really take it? I do use a circular saw blade from stew mac, although not with a table saw (I use my sliding miter and jig). Yes, I slot with a square fretboard blank (I square one edge and this is my reference edge throughout the slotting and tapering process). Some people may actually choose to slot with a pre radiused board so that they can maintain a uniform slot depth for the fret tang referencing the radiused surface(what you are calling kerf* these are not really relief cuts so you will find most people call them fret slots FWIW). If you slot without referenceing the radius, you may have to adjust the depth after radiusing or leave an extra deep slot (some feel that is sloppy, others see it as acceptable). With regards to tolerances. Yes we work in thousandths. It may seem silly because wood expands and contracts with moisture levels, but you will find some parts require this level of accuracy. If you are working with the shape of a body, not a big deal(at least at the level of thousandths of an inch). If you are working with a neck, yes thousandths count. Positioning the frets as accurately as possible is something we try to achive. You will find that the scale used and fret positions are not perfectly located because of variables that are unavoidable(such as the act of fretting a string, which raises the string tension). That said, we adjust the length of the virbrating scale to get the fretted note closer to accurate (called adjusting for intonation). Some people do not try to adjust fret positions to take any of this into account, some will actually make very small adjustments in fret locations. By misplacing a fret by a few thousandths of an inch, it may only through you off by a cent or less, but do to the inhearant inaccuracy you are fighting you may already be a few cents off and this make the situation worse. Best bet is to try for as accurate as you can be. Since we are chatting about accuracy. Take a look into setting up a neck, and the tolerances that we try to achive. You will adjust a string nut so that you have .005" clearance over your first fret or closer. You will allow for .010(high) to zero relief in the neck itself. Some people prefer to achive very low action(depending on the string 2-4/64ths) average (3-5/64ths), and given that a strings vibration(depending on how hard the player plucks the string) will account for just about all the clearance allowed for you are dialing in the action to just a few thousandths tolerance. Good things to keep in mind when constructing, and choosing material. It makes some of the things that may appear on the surface to be overkill, a little more easy to accept. I can absolutely promise you I work in thousandths on my acoustic guitars on even more parts of the instrument. As for the Carbon fiber. It is becoming very common to use it on instruments. Especially on necks. You may want to consider the orientaion of the material you add, with regards to the planes that will resist the most force, and are most critical in terms of functionality. A thin flat laminate placed parallel to the fretboard is going to be of marginal value, perpendicular to the fretboard will add significantly more strength and stability as it relates to the strings and fret to string tolerance(speaking to stability). With regards to laminate necks as you describe. There is a company that has been very big into laminates similar to what you describe (for the life of me I can't recall which company right off the top of my head, but it is a major brand). Maybe someone will drop the name of the company I am trying to remember here (think big on Spruce laminations). Peace,Rich Quote
dry pond wood works Posted February 14, 2008 Author Report Posted February 14, 2008 I do use a circular saw blade from stew mac, although not with a table saw (I use my sliding miter and jig). Yes, I slot with a square fretboard blank (I square one edge and this is my reference edge throughout the slotting and tapering process). Some people may actually choose to slot with a pre radiused board so that they can maintain a uniform slot depth for the fret tang referencing the radiused surface(what you are calling kerf* these are not really relief cuts so you will find most people call them fret slots FWIW). If you slot without referenceing the radius, you may have to adjust the depth after radiusing or leave an extra deep slot (some feel that is sloppy, others see it as acceptable). With regards to tolerances. Yes we work in thousandths. It may seem silly because wood expands and contracts with moisture levels, but you will find some parts require this level of accuracy. If you are working with the shape of a body, not a big deal(at least at the level of thousandths of an inch). If you are working with a neck, yes thousandths count. Positioning the frets as accurately as possible is something we try to achive. You will find that the scale used and fret positions are not perfectly located because of variables that are unavoidable(such as the act of fretting a string, which raises the string tension). That said, we adjust the length of the virbrating scale to get the fretted note closer to accurate (called adjusting for intonation). Some people do not try to adjust fret positions to take any of this into account, some will actually make very small adjustments in fret locations. By misplacing a fret by a few thousandths of an inch, it may only through you off by a cent or less, but do to the inhearant inaccuracy you are fighting you may already be a few cents off and this make the situation worse. Best bet is to try for as accurate as you can be. Since we are chatting about accuracy. Take a look into setting up a neck, and the tolerances that we try to achive. You will adjust a string nut so that you have .005" clearance over your first fret or closer. You will allow for .010(high) to zero relief in the neck itself. Some people prefer to achive very low action(depending on the string 2-4/64ths) average (3-5/64ths), and given that a strings vibration(depending on how hard the player plucks the string) will account for just about all the clearance allowed for you are dialing in the action to just a few thousandths tolerance. Good things to keep in mind when constructing, and choosing material. It makes some of the things that may appear on the surface to be overkill, a little more easy to accept. I can absolutely promise you I work in thousandths on my acoustic guitars on even more parts of the instrument. As for the Carbon fiber. It is becoming very common to use it on instruments. Especially on necks. You may want to consider the orientaion of the material you add, with regards to the planes that will resist the most force, and are most critical in terms of functionality. A thin flat laminate placed parallel to the fretboard is going to be of marginal value, perpendicular to the fretboard will add significantly more strength and stability as it relates to the strings and fret to string tolerance(speaking to stability). With regards to laminate necks as you describe. There is a company that has been very big into laminates similar to what you describe (for the life of me I can't recall which company right off the top of my head, but it is a major brand). Maybe someone will drop the name of the company I am trying to remember here (think big on Spruce laminations). Peace,Rich Quote
Woodenspoke Posted February 14, 2008 Report Posted February 14, 2008 I am totally new to this, but I am an experience woodworker and boatbuilder. My son wants to build a solid body elec. guitar, so I have begun reading up...already I have some questions. --I noticed that people tend to taper the fretboard then using a centerline, cut the fret kerfs. Wouldn't it be easier to cut the fret kerfs while the board is still square and then just taper it? I noticed that Stewmac sells a small table saw blade for cutting the slots, so I would assume that someone is doing it this way. --With regard to necks, has anyone ever just laminated a neck with horizontal veneers and just laminated the curve of the "machine head" right into the neck as one piece instead of glueing it on later? I have access to a vacuume press and we do this kind of thing all the time. It would be very strong and would probably look cool as well. I was even thinking of putting a layer of unidirectional carbon fiber between some of the outer laminations to give it real ridigity against the strings...like a built in truss rod. As I said, I am new to this whole thing so maybe this has all been done. I love the web sitel Allan I would not worry about tear out since you have to taper the board after cutting the frets. Yes use a square board to cut frets. Don't forget you have to radius the fret board too. Radius and fret slot depth of cut is important since your slot will loose depth as you radius the board especially on the lower board closer to the body. I didn't read the posts here so maybe I am just saying the same thing. If you build boats this should be an easy project for you. The neck is the most important part and I suggest buying a fret template to use with the fret blade to save pulling your hair out. Hand measuring is overrated and the extra money is worth the security of proper fret placement. You can always sell anything on eBay you will not use again. Adding all the additional exotic material is not a requirement and unnecessary, but I do suggest a good straight edge and a double action truss rod. Ther are many ways to glue up a neck even make up your own method. Whatever works for you go for it. Quote
madawgony Posted February 14, 2008 Report Posted February 14, 2008 Well said fryovanni! Thanks for your response. I would have thought that you would kerf it on the table saw THEN radius it. If you radius it first, how do you keep it level when you pass it throug the table saw? Also, when I see these tables that give distances from the nut to the frets, the dimensions are to 3 decimals. Is that really practical? You can't measure and cut in a typical woodshop to 1/1000th of an inch. How far do you really take it? I leave an edge around the fretboard so that it will lay flat on my cross cut sled. Check the link below: Pre-tapered Fretboard Disregard the time stamp on the pic, my camera is fubar. I took these pics tonight. The radiusing jig I use is below: radius jig Quote
fryovanni Posted February 14, 2008 Report Posted February 14, 2008 So what are you guys using to measure the fret distances? Surely there is no ruler that accurate. I did see a template sold by Stewmac with little cuts on the edges. Do you use digital calipers? I do disagree with one thing that you said...if a neck is made up of a number of veneer laminations that are parallel to the fretboard and you interleave some unidirectional carbon between some of the outer laminations (away from what we call the neutral axis) you are adding a lot of resistance to the bending moment of the strings in the same way a truss rod works. I did see one neck made by Martin Guitars for an entry level guitar with a totally lamiated neck. Is that who you are thinking of.? The two methods I have used to locate fret slots. First with a slotting jig and pin, second I have drafted templates in auto cad printed them 1-1 with each fret slot marked with a line that is the same thickness as the blade(if you see any line after slotting you missed your mark, the lines make it very easy to visually alight the blade right on the mark). To check distances or thickness on critical elements, calipers are the ticket, rulers are pretty useless for high accuracy marks. I do use rulers with slots for mechanical pencil lead(.5mm) though for ruffer marking, and if it is a very casual marking I may use a standard rule. A lot of my more critical parts are made with jigs that I have made with great attension to accuracy. Make an accurate jig and you can limit how often you are manually measuring (better repeatability). Yes, I think I mis-understood what you meant. I was thinking you were talking about adding laminations to the outer edges(in my head I read outsides* my bad). The point I was making when I said this-As for the Carbon fiber. It is becoming very common to use it on instruments. Especially on necks. You may want to consider the orientaion of the material you add, with regards to the planes that will resist the most force, and are most critical in terms of functionality. A thin flat laminate placed parallel to the fretboard is going to be of marginal value, perpendicular to the fretboard will add significantly more strength and stability as it relates to the strings and fret to string tolerance(speaking to stability). Relates to a taller brace will increase in strength significantly faster(getting farther away from the neutral axis) than a wider brace or beam. Either way I guess my suggestion was aimed at increasing the height of your brace, which does translate to increasing the distance from the neutral axis instead of increasing the width of your brace. It is an interesting thought. I think there was some discussion of doing some testing with CF laminations in different orientaions to get some real world test results, but I don't think that any results have surfaced yet. You know I think that was Martin. I don't recall hearing any bad feedback on the performance of those necks(entry level or not). One nice thing about following a method a manufacturer has used, is that they don't generally want to risk warrenty issues, so they are careful with methods. You also can get a fair bit of feedback as to how people like the design or materials. Peace,Rich Quote
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