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GuitarEng

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Everything posted by GuitarEng

  1. If you are just interested in CNC as a hobby then build one yourself. If you are interested in it as a tool, then buy one. If you can take a block of wood and turn it into a neck in 1 hour (profiling, headstock contours, tuning peg hole drilling, and carving), then don't waste time with CNC! It would be hard to make a similar argument against CNC for inlay. One-off's are pretty easy if they are truly one-offs. You have to design everything at some point...and if you have your CAD skills down then modifying existing drawings and making code from them is pretty trivial. For metalworking, you need a CNC mill, not a CNC router. Unless you can afford something suitable for both (i.e. a used Fadal for between $25 and 50k) then you will need to chose one or the other. You definitely don't want to do metal working with a K2. I use Fadal's at work and I have a K2 at home. CNC is the way to go for me...but I have 15+ years of CAD. If you aren't up to par on CAD then that is the first step. I pretty much do CNC all day, most days, let me know if you have any questions. G-Eng
  2. I can also CNC cut pretty much anything you would want within reason. Send me a sketch and I'll send a quote. G-Eng
  3. I thought some of you might get a kick out of my latest design. I'm looking for comments both positive and negative...lay it on me! I designed everything using Rhino CAD and then cut the parts using my CNC machine. Here are some pics: Peace, G-Eng
  4. I use ebony...oh yeah...the CNC machine helps out a lot with this... -G. Eng
  5. You're really just inviting a headache if you make a single piece guitar...mainly due to wood movement. If you do attempt something like this, I'd recommend using something fairly stable such as mahogany or rosewood. As for tonal differences due to adhesives...I think that's stretching it. There is absolutely no such thing as perfect tone..it's completely subjective. I would really doubt that a .002" thick layer of glue really affects "tone" (however you define it) to any appreciable degree. There are a TON of things that matter way more than how thick your glue line is. My advice is to worry about those things. That's my .02 G-Eng
  6. I've always understood that you need mass to get good sustain. Pick the heaviest block of wood you can find and that will sustain the longest.
  7. Ditto on what Mattia said - take your time and do the design right. Draw it all out with the right angle & everything..
  8. You'll probably see me advertising on here before too long. All of those things have been in the long term plan... In the meantime, let me know if I can help you out with anything!
  9. Yeah...it's cool stuff. I'm looking to start running a lot more stuff soon. The wife tells me I have to actually make money...apparently I promised something along those lines at one point...
  10. Thanks for the compliments! I cut it on my CNC - I have one of the K2 Machines. I did all the design & surfacing work using Rhino & ran my toolpaths with RhinoCAM. I didn't have any bookmatched wood laying around...and I thought it looked cool having the pieces flipped (the top wood pieces are sections from the same board)...the swirl on the top opposing the swirl on the bottom, etc. I was going to go with much more standard F-holes and did this one on a whim. I've seen some other f-holes done per the grain lines..and this is my first go at doing it with the CNC.
  11. Here's the latest body off my CNC machine..it's a Semi-Hollow Singlecutaway design with the F-Hole designed to mimic the grain pattern. The body has a 2 degree taper between the top and the back and it has a nice rounded carve transitioning from the top to the sides. Oh yeah...the back is a single piece of Mahogany and the top is Black Walnut. Let me know what you think..here's a pic of the body with the top wet down...
  12. I would think that rosewoods and ebony are used for their stability and strength. It probably doesn't hurt to have some weight to the bridge either. Rosewoods and ebony are pretty stiff...if they were more flexible, this would probably steal some energy from the strings instead of transferring the energy right to the soundboard. I think there would be some obvious problems with using a softer wood for a part like this...over time & under load, the part would deform due to the string tension & load across the saddle.
  13. I'll CNC cut them if you want....I can do rounding, slotting, profiling, and do any inlay routing you may want as well....Message me if you are interested.
  14. I've got a K2 3925 machine and it is repeatable to within about .002. This number includes all sources of error from all 3 axis. I highly recommend it...it is good for "slower" production work. The main limitation is the size of the spindle (which is a 3.25 HP porter cable router)..and the flexibility of the frame. Even so, it is definitely faster and more accurate than doing things by hand. The compucarve thing is not geared towards inlay...or really any other parts of guitar making. A machine like the compucarve is controlled via stepper motors whereas higher quality machines make use of servo motors. Stepper motors only move in certain increments..and when they wear out they miss steps. The machine controls position of the axis by counting how many pulses it sends to the motor. The servo motors on my K2 have optical encoders...they constantly feedback their position to the controller PC. For anyone who is interested in getting into CNC, I highly recommend you download a copy of Rhino CAD software. If you get to the point where you are comfortable with CAD, then you are ready to go to CNC
  15. one last thought to add to fryo's would be that you probably aren't going to drastically change the way the instrument sounds if you 1) build it out of normal woods 2) build to pretty standard dimensions 3)brace it using a standard pattern and 4) put the sound hole in a normal spot. You gotta play big to win big..if you're only making $1 bets, it's hard to strike it rich! And even then...there's always the possibility that the time tested designs we all play today are pretty darn close to an optimized design...
  16. Here's a cool pic - this is from a very simplistic Finite Element Analysis model that I ran for a prototypical acoustic soundboard. Without going into the details, I think it is indicative of the deformed shape that an acoustic takes on when it is under load. I'd also propose that as the strings vibrate, they basically form a bellows...with the back portion of the body "pumping" air out the soundhole...and the "tone" of which is probably dependent on the Helmholtz frequency. This tells me that you should put your soundhole wherever you think you'll get the most deflection...and that this should give you the most volume...
  17. Cool, congrats on picking up a seat of Rhino. I also have Rhino 3.0... I'll reply first to your 2nd to last post: Once you have done all the surfacing, you program the CNC so that it cuts the whole thing all at once. You don't cut the arm carve, then the binding, then the rest...you cut it all at once using either a spiral toolpath or a simple back and forth toolpath (depending on the part and your CAM software). With regard to how to model a carved top....I would recommend starting with a neck carve. Carved tops are definitely more difficult. In both cases, you will be using the following commands: *surface from 2, 3, or 4 edges *Lofts *Surface from network curves *Sweep 2 rail *Patch surfaces Each of these tools have their place. The general order of operations is to build a wireframe grid..and then to use those splines & curves to create your surfaces. Make sure when you do the grid that if you have two curves coming togethor, they are are tangent at a minimum...and preferrably curvature continuous. I'd recommend reading the book and then doing a lot of playing...you will need to spend a good bit of time on this in order to get good at it. Good luck!
  18. Hey Dave, cool site. I have a similar background & similar CAD experience (less UG & ProE). I have done a lot of CAD automation/Design Automation programming using VB, Delphi, and Lisp though - you can do some cool stuff if you get into that. Very nice web layout as well, it has a great look to it. I do have to take exception with your idea that Rhino is only good for making swoopy curvy things. It is especially good at this, but I feel it is as good as AutoCAD at the more mundane CAD tasks. With that said, it really doesn't compete at all with SE, SW, or Inventor as a solid modeler. Rhino simply calls watertight surfaces "solids". Yuck.
  19. The grid itself is inconsequential......when I'm laying out a part to show fret slots, or something like that, I'll draw the nut line and then use the offset command and then trim the slot lines to the edges of the neck. Most CAD systems allow you to enter coordinates/measurements so that you don't have to "eyeball" everything using grid & snap options. That would be a truly painful way to draw..! Whatever software you buy should come with tutorials & a manual...if you are new to the software you could probably get a lot of mileage out of reading through that stuff.
  20. I just saw the post about Solid Edge. I think that in the mid-level 3D CAD market - this means Solid Edge, Solid Works, and Inventor - SolidWorks is the best...and the other 2 are trailing. We use SW at work and it's a great package. I gotta get my jabs in for Rhino though...Rhino does some surface stuff that SW just doesn't do. SW is a much more well rounded package, but Rhino is a fraction of the cost...
  21. Tonemonkey - most shops with decent software can handle just about any curve that you give them. Splines are a pretty basic drawing element for most CAD/CAM programs...I'm surprised to hear that they are giving you a hard time about that. P90 - I'm in Maryland (I used to post under the name "TechArt", but I lost that login info!). A bit more on what TM was talking about...splines are 2D or 3D curves...if you were going to model a LP top, that would be done using surfaces (which are usually creating using a bunch of splines). Rhino is very capable of doing surfacing tasks like this...but surfacing is an art and it will probably not be a quick thing to learn. I chose RhinoCAD & RhinoCAM as my software and couldn't be happier with it. I feel that it is by far the most competitive package out there. I think the best way to get into CAD/CAM is to get into CAD first. You can only machine what you can draw...and even if you never grow to the point where you are ready to jump into CNC, CAD is an extremely useful design tool. Here's a screenshot of a surface I setup to carve a carved back for an OM style acoustic that I have been working on occasionally (it's basically an archtop-type surface): Here's a pic of the actual part, carved with that surface from Black Walnut..the outline is a bit rough because I bandsawed around the outside. After that, I glued it right to the kerfing and used the router to trim the back even with the sides (as you would normally do). I'm really happy with it, I think it's noticeably more comfortable than a regular acoustic back.
  22. That's the machine I have - I got it with the 8" Z and the limit switches. My only complaint is that they didn't provide hardly any info on the machine itself & basic operation. It wasn't hard to figure it out (I called them)...but it would have been nice to have something to go by!
  23. Yep, get something that will export dxf files. AutoCAD is not really a standard anymore...but their file format is a standard. Most engineering/design places are now using something like SolidWorks, SolidEdge, or AutoDesk Inventor. These are mid-level parametric modeling packages that work great for building parts & assemblies in 3D....cost on these is around $5000 per seat whereas I purchased Rhino & RhinoCAM together for $1600. MasterCAM is nice, but it also runs expensive...about $10k to start. Fadal 4020's are a popular model, a lot of makers use these machines. They also have a 15,000 rpm spindle which helps when cutting inlay, etc. A fadal will run you about $85k. I think the real justification for a machine like a Fadal is the quantity of parts that you are running. If you are only making one or two guitars a day, a Fadal is a much bigger machine than you probably need. A good starter machine (such as a K2) is available for about 10% of the cost of a Fadal....you just have to take smaller passes with the smaller machine. (I have a K2 at home) Let me know if I can help you out.
  24. Most any CNC shop will be able to run toolpaths off of dwg or dxf files. I use Rhino CAD/CAM with my CNC machine and have been very happy with it (I use MasterCAM, Rhino, SolidWorks, and AutoCAD at my day job). I've found Rhino is better than AutoCAD for artistic designs...AutoCAD is more for the mechanical/architectural design. Rhino has great surfacing capabilities...I'll use this for doing carved surfaces like necks & bodies. Haas and Fadal are both popular machines because they have decent spindle speeds (up to about 15,000 rpm), tool changers, and the accuracy of a low end metal working machine (they will generally hold .001"...which is very good for woodworking). You could probably pick up a very basic CAD program at Best Buy or something for around $100 (I believe Rhino is about $600). If you have a design (digital or not), I would be happy to work something out with you - just let me know.
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