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Everything posted by fryovanni

  1. I agree with what everyone is mentioning. A few thoughts that come to mind when I am bending quilted figure. I prefer a very solid form foundation, as smooth an supportive as possible. I build side forms with rectangular aluminum bar 1/8" or 3/16" is fine(about 1/2" tall, frequently placed) then cover with steel sheet. I use flexible sheet slats because I want to avoid extra tension from heavy slats while I pull the wood to the form. I use paper between the wood and slats and distilled water then seal the whole thing up with tape(masking tape works just fine for me). The idea, reduce the chances of staining(especially with maple), contain a small amount of water(too much water, creates puddles and doesn't really generate the steam your after, which seems to lead to uneven heating) and promote even steam contained until your finished heating the wood(you slice the tape when your locked down, give the blankets a quick warm up and your steam escapes quickly), keeping moisture evenly contained also reduces the chances of spot scortching. I prefer two blankets for better control, even heating, and I believe it is a good investment if your using expensive wood like quilted maple. Maintaining even pressure against the form is important, and you want to make sure you work to the outsides from the waist to avoid bunching or pinching the slats to create a bulge or distrotion(lock the middle and clamp the ends, then work the areas between would be a disaster* pretty obvious, but think about it when your bending to keep it extra smooth). Thickness of these types of figured woods, especially when your making sharper bends, and your ability to heat and make the wood flexible enough is tricky. These figured woods have very focused areas of weakness and strength because the grain runs so oddly. You need to be sure you are not too thick and will have trouble getting the heat up evenly. Supersoft, is a very sensible investment. Also take your time when removing the bent side from the clamps and form. You don't want the tension stored in your slats to crack the sides because you released the clamps too unevenly. Plan very well, do a practice run and make sure nothing will get in your way or make your life difficult while you should be focused totally on monitoring heating and a smooth bending process. A smooth bend is really important with quilted maple, because you will get some faceting that you will have to deal with when you are leveling and prepping the surfaces for finish. Extra distortion will only make the chances greater you will have to thin the sides a bunch(hopefully a bunch doesn't turn into too much) to get them leveled and smooth. Good Luck with your project
  2. Yes, you have to adjust for the blade angle, and every time you swap blades this needs to be reset. It is not a flaw in your setup because the shape of tires and the style of the blade will simply change the way it rides on the tires. This angle should be predictable and can be adjusted for with your fence angle. Keep in mind this is not the same as possible tracking error from uneven blade wear, dirty blade, beam distortion or any other number of issues. Keeping in mind this drift angle is important. One thing I have found to be problematic on many fences is simply the fence does not stay put. Some fences have a great locking mechanism on the infeed side, but lousy on the outfeed and or possible flex, you may also find some pretty flimsy plastic components or shims on infeed sides. This can lead to the fence being shifted as you cut then springs back, or possibly slips out of position. It is a problem made more noticable when you are cutting larger bits of wood. Longer boards tend to be more challenging to keep against the fence(which makes feeding straight challenging) and sometimes this means you naturally apply more pressure against the fence. Even shifting positions as you feed makes this tricky. Good technique in feeding material is tuff enough and making sure the fence is not going to move makes your job easier(so you don't have to worry about that factor). If you question the locking mechanism at all, I would add a solid clamping device to ensure it does not move. If the fence just does not seem solid after you additional clamps, grab a good reliable square block of wood and clamp it right to the table(not super fancy, but it does the job very well). A sliding table is another way to make feeding consistency more reliable(it is extra handy when you have to true up an oddly shaped block of wood).
  3. Pretty much. Watch out for bugs though. Remember though to consider the amount of time it takes to aclimate wood, not really fast thicker wood. Thin wood can aclimate much quicker of course.
  4. Depends on what you are doing Dugg. If you are repeating your cuts it is VERY important. Also if you are using extreamly tight tolerance. Point fence simply cannot perform with the level of accuracy I need. Sometimes an extra couple thousandths of an inch per slice, when taking 9 slices out of a billet will be the difference between 4 or 5 acoustic sets(and if those sets are expensive Rosewood or exotic that can be several hundred dollars worth of set lost). I have never found a great fence out of the box, not to say a Kreg or even some factory fences can't be tweaked to do a good reliable job. If you are doing some serious resawing, and you are not absolutely confident in your adjustable fence. Take it off or to the side, and clamp down a square block of wood. Be sure the block is aligned to the blade. This can be done by clipping a light and straight guide tool(I have a light weight 18" straight edge that I clip to the blade, Note; you have to avoid the teeth). Keep your blade clean! that is the source of many of the problems people think relate to dull blades, or odd random issues that are hard to figure out. This is a topic I posted a while back that shows a fence and slider table I use. http://projectguitar.ibforums.com/index.php?showtopic=31523 These are the blades I use. The Woodmaster(1.2 TPI) has the most resistance to clogging(big gullets). The Trimaster(2/3 TPI) is good for some woods and is reliable. The Woodslicer(4 TPI) offers extreamly low loss cuts, but is touchy and VERY prone to clogging. Ability to clear wood is a big part of stability(big gullets are a plus for this).
  5. Yep, Spoke said it well. Actually, the process of seasoning could be better if the wood is allowed to go through natural seasonal cycles. Not sure I put much into the theory behind seasoning wood, but it is a theory. The important thing is to aclimate the wood to the environment you will build in. Then control the humidity during the build. It is always safer to build a bit dryer than it will be in service. The greatest chance for damage will be if it becomes dryer than when it was assembled(much more stressful). If the moisture is higher than when assembled it will swell and you will likely get a little extra doming. If it becomes dryer you will lose doming, you may start really stressing soundboards and backs if it shrinks much more(sides do not like to yeild to a soundboard or back). Just the way I have always looked at it.
  6. Hey GW, I have been busy at my regular job so I have not had much time. The potential slowdown has made it a top priority of mine to keep the guys who work for me working(the thought of their families being disrupted is something I do not want to happen). So far so good, but I want to lock down at least enough backlog of work to carry us through 2010. I really want to get back to the tools soon. I miss it very much.
  7. I like ripping ebony binding strips and binding ebony boards. I like the clean look. I found a couple old pics. strips
  8. I think the premis of saving cash is secondary. Bracing for an acoustic only requires a fraction of a bd. ft. worth of wood, and even if you choose to pay for the best hand selected bits paying $10 bd. ft. The cost per. instrument is negligable. I see nothing wrong with looking for good bits of softwood in lumber form. However, you have to recognise the prices paid for "select" wood is based on that selection(don't get me wrong, some prices are WAY off base for soundboards. Don't pay crazy prices). With hand split billets of select Spruce, I will have a fair bit of waste and many lower grade cuts. If you buy lumber that is not selected(based on the tree and properties) you should expect much lower yeild of high quality bits(it is more of a crap shoot). You may luck out, or you may wind up with lesser wood. If you don't know what your looking for or have enough experience to know the difference between good or poor quality, you likely won't do well but may think you struck gold. So I think it is a great idea, but use common sense.
  9. You should also cut the wood close to the dimensions you will be using then mill the wood. You will lose a lot of material trying to surface a full length board with a bow than if you cut it to appropriate pieces for your parts. If you only have 1/8" bow in 40", it is not too bad. When you cut it down to say 21-24" for a bookmatched top billet, the amount of milling should be very slight. Use a jig to allow you to keep the reference surface for your milling if your infeed and outfeed tables are too small to reference the whole piece. I would opt for a jointer for your neck stock. I usually only care about one true surface(the back of the neck I ruff profile and shape, I use the surface the fretboard is attached to as my true reference surface).
  10. Seems like everyone is touching on the key concepts. Weight, durability, stability, stiffness. You should remember you also have the ability to adjust the thickness, size, shape, and how you taper to the surrounding soundboard. When you think of weight of a more dense hardwood, you could adjust the thickness a bit and bring the weight in very close. Specific gravity of say Hard Maple vs Most Rosewoods is about .6 to .8, and given the durability you should be able to thickness the rosewood a bit to adjust leaving you with a small weight difference. Stiffness is going to vary with thickness, shape and taper also. Just food for thought. Either way durability is not something I would not skimp on. You don't want to have to repair a bridge plate any sooner than you have to. Proper fit will cut down on the wear a lot more than a little difference in the durability of the wood you use.
  11. I love Doug Fir. Great wood if you find a good bit. Watch out for pieces with sap oozing, it can keep doing that for years and make finishing tough. Doug Fir also varies quite a bit in terms of stiffness. If you get a good stiff piece it is amazing, and quite resonant.
  12. If it is just a top for a solid body, you could resaw as thin as 1/8"(I suppose you could even go thinner, as people even use veneer in the 1/32" range). I resaw backs and tops for acoustic guitars at 3/16"-1/8" (finished/surfaced backs are usually in the .095-.075" range). Structurally you will be fine with 1/8"(drop tops have little structural requirement). As was mentioned though, think about any carves and asthetics.
  13. Yes, this is why you want to assemble in slightly dryer conditions. This way if moisture levels fall and the wood shrinks it hopefully does not go below the level at which it was assembled. If you assemble with higher moisture, and it dries significantly it is more stressful. This is also why many builders have taken to "baking" or overdrying soundboards prior to assembly, as this may help if the instrument is ever exposed to destructive low humidity levels. Swelling or higher moisture levels generally are not that dangerous after an instrument is in service. So it is better to keep humidity up. Case humidifiers are a good safety measure. Winter tends to be a very dry season, especially when you are in a heated space with very cold outdoor temps(relative humidity drops when temp is raised vs outdoor ambient temp). The desert will destroy an acoustic instrument that was assembled in a moderate climate. You need to keep the destinction between what is good during assembly, and what is good in service. How you assemble will set the level that is best for the in service conditions.
  14. So, the back and sides are fine not to be quartersawn? I know on my augustion AR-60 the sides are quartersawn and the back is close to quartersawn. That's the only acoustic I have to look at besides $50 ones. Quartersawn is prefered for stability, and the traditional choice. As Hector points out though, most of the back and side woods are getting harder to get (there is also cases where looks come into play over stability). Most would prefer to use at least quartersawn sides if possible even if wider backs are not possible, again it is about the stability of quarter over rift to flat. You can certainly use flat saw or rift(these are sometimes all we can get), just be mindful of the potential stability issue.
  15. What radius did you use for your back? Most people try to assemble in the winter or overdry a back slightly during assembly. Usually this will make the dome pop up a little stronger as the wood swells with an increase in moisture. You are safer that way, as assembling with a higher moisture level will create a situation where the wood will shrink and go concave or possibly even crack. If you do a little search on the web you should find a lot of discussion about this subject. I know some feel the month the guitar was assembled may be a clue as to why some guitars sound better or have survived a bit better. I recall reading about this on a forum, and several people had actually studied and measured the dome shape as it related to this. You don't want to build too dry of course, but high humidity during assembly will lead to problems.
  16. Vac. Bag is probably your best bet for laminating thin woods, especially if you are forming up a shaped part. You really don't need high clamping pressure, you need even pressure. The vac. bag system also allows you to use shaped back forms, instead of top and bottom forms with clamps.
  17. Kp, I am glad to hear you found some answers, and that you have not given up on laminate construction. There are some great design concepts such as using lighter, less stiff but resonant core woods with denser, stiffer and more durable outer laminates that offer some great strength(directional) to weight advantages. Combine that with the artistic oportunities, and it would be a shame to discount laminate construction.
  18. Pete, I am not sure what your getting at. I am not compairing a solid bodies performance to an acoustic, nor trying to corrilate design considerations. I definately have no idea what "acoustic instrument lore" you are talking about. I made reference to some material testing that I had done with regard to spruce for soundboard use, but the reference was regarding general properties and deviation from bit of wood to bit of wood. I made the comments because of the testing that was being discussed. I do believe it would be helpful to think about some of the charictoristics(density, stiffness and such) if your going to try to compair the resonant responce of materials through testing. If you look at my posts in a few recent topics relating to electric/ acoustic "hybrids" you would see I am not one to say acoustics and electric design and function translate easily. Actually, I am probably more enclined to say the two are based on such different systems they shouldn't be confused(although I do respect the opinions of people who find the acoustic design properties integrated into electrics often make for results they find very cool). Kp, You don't need to prove anything here, and unless you are doing this to try to understand the material better to suit your own curiosity, your pretty much wasting your time. As many of those negative plywood posts are out there, you will find as many other solid woods that are also put down for various generic reasons. You will find plenty of unfounded supporting comments for any number of woods or even laminate combinantions. Most of the time these are personal opinions. Even if you provided some silver bullet for plywood here today. In about a week or two you would see another negative plywood comment, likely something about glue killing or sucking "tone" with no foundation short of a strong gut feeling.
  19. And there may be your answer Certainly, does seem like we are wasting a lot of time building electric guitars when we should just be swapping pickups
  20. Kp, I think your search for an answer * is something that is reasonable. You are starting to look down the road a bit though, and are seeing that you are going to have to identify what you are compairing(thus your comment about the wood needing to be of the same type). Given the wood was the same species, the next question would be what are the differences in the two samples of the same species. Is the plywood sample denser than the solid sample? Then is one sample stiffer than the other sample and if so is it the difference related to the plywoods assembly of the wood itself. Hopefully you would be able to confirm moisture content was very close in both samples, but that may take some aclimation time. You would also of course have to be dead sure both pieces were equal in dimension. After you identify the differences(and they will be different) you will have to figure out if the different performance relates to the difference in the properties of the wood, or the by product of the laminate construction. This will be a very daunting task to say the least, especially with limited control over the manufacturing of the ply. It may be that instead of jumping into model analysis it would be more orderly to start with material analysis. That way you can understand the materials, then move to modeling with control or recognition of variables. This way you could for instance insure two bodies used in a test have similar density, even if variables in stiffness are just a by product of the plywood construction, or vice versa. After playing with spruce used for soundboards, and really focusing in on natural ranges of properties from bit to bit. I have really come to realise some significant potential for variation. I have also recognised the significance of certain attributes that account for much of this variation(such as grain orientation, growth patterns, density and such). I would certainly say it is not a total crap shoot as to what properties you will get if you account for these notable features, although you still have smaller variations that are difficult to nail down. Actually, many of those features are also used to develop grading criteria for plywood to ensure some minimum performance garentee(although within much wider range of tolerance, for most grades of ply). I think with musical instrument wood there is a history of importance placed on selection of materials for this reason, at least with acoustic instruments where pushing the limits of efficiency and performance are highly valued.
  21. It is a good thought, but there are a couple things you should consider. manufactured Plywood is very inconsistent. The orientation, grain structure, potentially voids, density of material used, moisture content and such is significantly less predictable than solid wood(at least you have visual clues with solid wood, or even ply you assemble yorself). If you are being true to your testing you have to acknowledge this, and I am not sure how you would quantify the wider range of variance. How you deliver the energy to the string. This is a variable you have to control and repeat consistently, or your results will vary with input. How you collect your data samples. Again consistency, and control over contamination. Range of data and how relevent it will be to a real world instrument application. An open note may produce a bit of info, but instruments have a range of possible positions. How one material acts at a given low range frequency is one thing, but how it acts as the frequency is raised may vary differently from material "B". We understand materials potentially respond differently at different frequencies, and that may have to do with density, stiffness, structure, oils and other factors common to a given bit. Also moisture, temperature and other factors will play a role. It would seem to me that a more productive approach would be to try to understand the corrilations between things like density, stiffness, orientation and so forth. These are common properties that can be translated to a broader range of materials. Bigger tools so to speak. If you limit the study to plywood vs solid wood, and draw conclusions. What about a very dense bit of plywood vs a less dense example, or even a couple bits that vary in stiffness. Bits will vary, so that will be the next step in your study and you will have to start exploring basic properties. Edit; FWIW, I recall a little testing I did a while back. There was a discussion relating to the effect of grain slope on ultimate strength and stiffness in Spruce. I thought I had a reasonable test. I simply used a piece of wood to cut a handful of samples. I split the wood taking great care to control slope. I used the most basic test rig I could think of with attension to consistency. The results clearly supported my beliefs, and I did take measures to blind myself to what material was being tested. However, the test was only as good as the size of the sampling(which is of course pretty limited, as I only used one billet of spruce). It was not a real world model(as in a functional part of an instrument), so other factors may very well alter the results or significance. Even the directionality of forces did not mimic a real world situation. The test had to be simple for control, but that is the catch 22 of much testing. I did walk away with data that showed basic properties, and that is a tool I will use for what it is worth.
  22. I think it is important to look at engineered materials and why or what the intent was. As I was saying, using construction grade plywood as an example. Was that the choice of material and intended application are sensable, efficient, and effective. If you are designing a composite for a neck you should certainly look at the needs and materials you have available. You can then design your material to best suit that application. The Martin neck is a great example. The material that is used for the neck makes sense. We have fewer large, straight grain, clear trees available today. By laminating more pieces that are smaller we are able to use pieces that are all clear and straight grained, all of which can be oriented in the best way to provide strength and stability for a necks requirements. Very sensable. Using other components such as heavier yet stronger materials surrounded by lighter materials to take advantage of design principles that can add to the efficiency is sensable(think of how we construct beams, in situations requiring directional strength). You can follow those principles in body construction as well (think aircraft floors, walls, wings). Now the key to a really good design is going to stem from a really good understanding of your needs. Which is kinda where KP is heading with his research. The trick and where this line of study becomes a challenge is when you get to the subjective points. Basically the requirements will vary with the intended performance. Unlike orchestral instruments we embrace all sorts of distortion from pure tonality in the timbre of our instruments. So your solutions will never be "one size fits all". I think understanding or being able to accept that will help keep your findings more meaningful. By that I mean you will find "soft" material acts in such a way, which is what it is(good or bad? depends). It will also allow you to look at the fact that material is soft, but is also light, and that in a larger volume it has the same weight as another material however it is three times as stiff. A greater unbiased understanding of the materials we can use will give you a bigger arsenal when you are trying to achive a design goal. P.S. Kp, When you say this- If you want to find meaningful information, keep your test simple. You are going to find there are so many variables that may impact your findings in a "full frequency spread available from plywood and solid wood"(not exactly sure what that means) that your results may not have much real usefulness. I have found even the most simple and direct models have variables I did not recognise. Just thought that was worth mentioning.
  23. You make a lot of good points, but I think some conclusions could use a little extra consideration. First of all wood is a fiberous material. The orientation of those fibers depends on growth patterns, environment and species. Although there is a lot of variation in these factors they are not without some sense of uniformity(which can be controlled to a degree with selection). Actually this is the tool used to develop the properties of plywood. Plywood as an engineered material uses averaging of variables to limit variation in charictoristics, as well as make use of more of the material which is available(some of which would not be suitable for a given application on its own). Wood that is comprised of wildly twisted fibers can be sandwiched with other material that is oreinted in alternating general orientations to create some sense of predictability. Now that does not mean the wood is the ideal or even close to ideal per. its total volume, but it has been made acceptable at a certain lowered level of performace within a reasonable range of consistency for its intended use. The sum has become better than the weaker parts it is made up of. If the application requires stability and strength in all directions, and the requirement for strength is in a given range, and weight or efficiency of the material is less critical(Need more strength add more sheets), and of course cost and availability of material is a factor. Using a construction grade plywood for constructing a strong wall or table may be an outstanding solution. Not all the wood used to make the plywood would have met the requirements, and certainly would have not had the same directional strength or stability on alone. A great use of wood for sure. We have to recognise though that you can select wood that is more predictable, has fewer flaws, and orient it as plywood is oriented and assembled. Then come up with an engineered product that is more consistent and stronger than a common construction grade plywood. It is all about averages. To expand on strength and stability. Both of these factors relate to the orientation of the woods fibers. If you need strength on two directions equally it makes perfect sense to take advantage of alternating the fibers(same is true with carbon fiber layups), but if your application requires a significantly higher strength in on direction then you are gaining nothing from this alternate orientation(quite the contrary, half your wood is oriented cross grain which holds about 20% as much strength relative to the direction the strength is needed). Stability in terms of expansion and shrinkage with moisture has similar directional relation and you can actually reduce your effective stability in a singular direction if you choose to mix cross grain orientations(longitudinal orientation varies significantly less than either the radial or tangential orientation. Since the body on a guitar or neck has very directional strength and stability requirements. It would be a wasted compramise for these reasons, although a solid body is VERY over engineered vs requirements to resist string tension(remember an acoustic uses heavier strings than an electric, with a lightly braced, approx. 1/8" thick soundboard and survives) and you can get away with less. So really the advantage to using plywood(again unidirectional and or construction grades) comes down to availability and cost. Lower grades of plywood are cheap and available so this is an advantage. If you actually have an application that requires unidirectional strength and stability. The plywood may very well hold an advantage. On acoustics the tail block and even neck block have these requirements, and plywood has become very popular. So it all comes down to application to me.
  24. I see a lot of topics about acoustic/electric hybrids lately. It would be nice to hear more about the concept behind why or what the designs would do to effect the sound of the instrument. I don't discount the viability or potential for a cool design concept to make changes in the performance that could be really neat. So don't tke my comments as cooling down your ideas So will it sound good or bad electrically, kinda hard to say, but your changing the weight and that is something(might effect the stiffness of the guitar a little also). Will it have a lot of acoustic volume? Very unlikely, you are not creating a system designed to produce acoustic volume. Some food for thought, or conversation... I have always tried to wrap my head around these things from a basic concept. What will a modification do to the way the strings vibrate. I think of the strings as having the potential to produce a certain amount of energy when plucked(granted, how hard or soft could certainly modify how the points they are anchored to will operate in the relationship.). If the support structure is rock solid(or very close to it) and very heavy, basically very difficult for the strings to set in motion. The strings will vibrate based on their elastic properties and energy provided to drive them(kindof a low loss, closed system). Certainly there will always be some losses, even a pickups magnetic field will at a minimum provide some drage, but lets assume it minimal. From this starting point you can start to weaken the support structure and bleed off energy to set the structure in motion, after the structure is in motion you will have a second motion that is effecting the vibrtion. Actually, a second is probably very over simplified, as the structure will attempt to move as the strings, but will not be able to because it is not able to move in unison, the modified mirror image will attempt to set the strings in motion in some out of phase motion. If you can image a perfectly out of phase relationship, it would pretty much act to stop the string movement rapidly. Since setting the structure in motion will cost you more energy than is returned to the system(again somewhat out of phase from the original motion) you would want to carefully consider what your doing with that energy budget. Think of a very heavy but flexable structure such as a big hunk of rubber with the strings attached. You will flex the rubber with relative ease and transfer energy, but the energy return would be slight(very heavy loss in the system). You get pretty complex when you start to think about balancing how hard it is to set something in motion, how well it will stay in motion and then add the complexity of differing frequencies. When you take an acoustic instrument, your thinking is all about transfer of string energy to produce sound, and then contend with reactive components to make use of every last bit of energy to keep driving that box. When you think electric, you are not looking to drive the body to produce sound, you read the strings. So the relationship is a very different one. Some of the charictoristics of an acoustic are not really great for an electric (such as the very high losses of energy, that are what we fight with acoustics). I think some of the rich and complex harmonic content that is developed when we try to make use of every bit of energy in the acoustics boxes system may be something appealing. So maybe a good plan of atack is to start with something that will be able to move without draining off too much string energy. A basic premis in acoustics, is to use only as much weight as is needed. So that may be a great place to start. If you have a reasonably light support system, that is very rigid you still have very little loss and of course little interaction. So from that point you can start to allow a greater degree of flexability into the system and should get more interaction. You could choose to add flexability to different parts of the system to achive what every results you think are best. A person could do a whole lot of testing with a bolt on guitar, as you can easily change or modify necks and bodies in different combinations. Another thing about starting light and stiff(and backing off to taste) is that you could also add bits of weight to specific parts to test for changes in responce(the headstock for instance). When you are using energy to introduce new motions, you have to keep in mind it is all about trade offs. It is possible to reinforce some frequencies in an terrible sounding way, or counter act the strings and kill the motion. It is just as easy to create muddy distortions, as it is to create interesting complex distortions. Just kinda some of my thoughts and theory. Can't say if I think about this stuff correctly, but it is how I have come to think about this stuff.
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