Free software for 3D model to feed CNC?

Discussion in 'Luthier's Corner' started by StuartV, Feb 20, 2014.

  1. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    I'm a software developer for a living and I've done some simple work in AutoCAD a LONG time ago. And I did one "build" so far, using a Warmoth body (that was completely routed and painted) and an Allparts neck (that already had tuners and nut installed). Now, I want to design and build my own bass from scratch. I have basic carpentry skills but no proper woodworking skills or equipment.

    In light of my skills, experience, and equipment or lack thereof), I'm thinking of designing my bass in CAD/CAM software and sending body and neck blanks off to be CNC milled. To that end, I've been looking around for software to use to do the design.

    Requirements (I think):

    - software is free. No free trials.
    - produce a 3D model in some standard format (DXF?) that I can give to shop that will mill the parts for me on a CNC.
    - does not require me to place my designs in the public domain or grant any kind of license on them.

    I've already searched and read up on things here and have compiled this list:


    - Blender - totally free. Professional level software. But, seems more oriented towards creating animations and 3D graphics. May not produce appropriate output for a CNC shop.

    - eMachineShop - totally free. But, I'm not sure if it's really good for doing the kind of curves I'd want to be able to do.

    - BRL-CAD - totally free. Software used by the U.S. military to model weapon systems. Supports NURBS.

    Others that I've ruled out:

    - DraftSight - Free, but not oriented towards doing 3D models. It's a clone of an older version of AutoCAD (2010?). It CAN do 3D, but it's much more tedious to use it for that, since it's really intended to be used for 2D.

    - 123D Design - Appears that free version does not allow you to use it for commercial purposes. So, I could not ever sell a bass I made using my design. And I'm not sure the free version will export a file that can be used by a CNC shop, either. They really want you to use their software and then pay them to print your object on their 3D printer and ship it to you.

    - TinkerCAD - Web-based, which is definitely not what I'd prefer. It was totally flaky for me when I tried to use it. And it appears that if you use the Free version, you are required to put an Creative Commons public license on them.

    - SketchUp - Doesn't appear to allow exporting drawings in a format that I can give to a CNC shop. Also, one contract CNC shop already told me that SketchUp is useless for producing files to give them.

    - DesignCAD 3D Max - $100. I could do that, if no free version will cut the mustard.

    - TurboCAD Deluxe 20 - $130. Again, I could do that, if no free version works for me.

    - Aspire - Expensive.

    - Cut3D - not really a 3D modeling tool. It's a tool for taking a 3D model and making a CNC program, as I understand it.

    - vCarve Pro - for 2D. Not really a 3D modeling tool.

    - Chief Architect Lite - Expensive and really specific to designing homes. Requires an even more expensive version to get the 3D modeling tools required for modeling a guitar.

    - AutoCAD - Expensive.

    - SolidWorks - Expensive.

    - Maya - Expensive.

    - Rhinocerous - Expensive.

    ps. There is a big list of 3D Modeling software here:
  2. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    So, can anybody give me some insight on any of these?

    How about Blender, eMachineShop, or BRL-CAD, as far as which one would be better or easier to use?

    I'm not so worried about the learning curve. Learning software is what I do for a living. I'm more concerned with which one will be better once I learn how to use it.

    Is there any other software (for Windows) that I should look at?
  3. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    ps. seems like this subject might be sticky-worthy?
  4. spz8


    Jan 19, 2009
    Glen Cove, NY
    While Blender isn't really geared towards CAD/CAM, it can be used for this depending on how tight your measurement tolerance needs are. The learning curve is quite steep, although much of what it can do (particles, sculpt, physics, etc.) may not be critical to your use. If you can scrape the money together, and need NURBS, Rhino is amazing (haven't used it, honestly), perfect for product development. Blender has very limited NURBS support, but has great poly/curve tools, and of course is FREE!
  5. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    I read (earlier) what NURBS stands for and still don't know what it really is. Therefore, I don't know if I need it or not. But, with Rhino being $1,000, it is right out of contention.

    And if you haven't used Rhino what is your basis for recommending spending $1K for it over Blender for free?
  6. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    Okay, I just read up on NURBS.

    It looks like it would be really nice for making the curves on a guitar body.

    But, you said Blender has great poly/curve tools.

    So, I'm back to befuddled on why Rhino would be worth $1K versus Blender.
  7. spz8


    Jan 19, 2009
    Glen Cove, NY
    I've watched a lot of demo videos showing the Rhino toolset and how easy it is to create some VERY complex organic/machined models that would be agonizingly difficult to build with a polygonal-based modeler like Blender. That said, with sub-division surfaces, Blender can create (and easily modify) some things that a NURBS modeler would itself struggle with.

    Here's a great intro video to learn about modeling with sub-division surfaces...

    I have TONS of Blender resources I can share if you're interested. Perhaps PM would be a better bet, but I'll be happy to further contribute to this thread if anyone else is interested. Good luck!
  8. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    Cool! Thanks, spz8! I will check that stuff out. And I definitely appreciate the offer to help with Blender!

    Regarding creating organic/machined models using Blender, I checked out this tutorial earlier. The tutorial steps you through creating a very "fashionable" watch, with multi-link bracelet. It is done pretty quickly and the result certainly doesn't have the look of being "polygon based".

    Anyway, I have downloaded Blender and started to play with it. And now I've also downloaded BRL CAD, but not installed it yet. Since BRL CAD does support NURBS, I definitely will give it a good eval before I commit major amounts of time to Blender.

    And I want to check out the eMachineShop software, too. I saw a guitar design that Hopkins (I think it was) did using that and it looked sweet, with a nice shape to the body. And I believe it was his first effort at ever using CAD software.
  9. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    Thanks, Stealth.

    That is TurboCAD 16. I have TurboCAD 20 in my list above. It would be about twice as much money ($99 on Amazon vs $55), but if I end up spending money, I would spend the extra to get the current version versus one that is 4 revs old.

    As it stands, however, it really looks like one of the free options will be MORE than adequate. I just have to settle on which one to use.
  10. Rodent

    Rodent A Killer Pickup Line™ Commercial User

    Dec 20, 2004
    Upper Left Corner (Seattle)
    Player-Builder-Founder: Honey Badger Pickups & Regenerate Guitar Works
    my suggestion would be thus (in approx. order):

    - learn how to build the perfect bass utilizing hand and power tools, get all the details down to perfection, and learn where dimensional tolerances are critical and where they're more of a general guideline

    - learn how to read rough lumber and how to mill it into the stock sizes you need for each part

    - learn how wood moves while being milled and machined, and how it moves with changes in ambient temperature and humidity

    - learn how to make tolerance fitting templates without CAD or CNC tools

    once you have these skills you'll have the initial grasp on what you need to accomplish with CAD, CAM tools, and the CNC machining process. without this understanding you'll be lacking the ability to know

    - when to use 2D or 3D in the design and machining process

    - how to design the right amount of slop into the part interfaces

    - how wood is going to react to each step in the machining process

    - how to choose the right piece of wood for the part you're making ... or maybe better said as - how not to choose the wrong piece of wood for the intended part

    - when you have machined a wood surface to the right level of doneness, so you can make smart decisions on when to stop wasting time machining and to start detailing by hand

    there is a lot of guitar making that needs to be accomplished before wasting time and materials designing something that looks brilliant to an engineering student but that fails miserably in the implementation. you aren't going to recognize this to the level you need to until you've done the actual work for real and have a consistency from one build to the next that meets/exceeds what's coming out of your typical overseas sweatshop

    all the best,

  11. spz8


    Jan 19, 2009
    Glen Cove, NY
    ^^^ I'm all for 3D modeling, but the above is excellent advice. I would suggest to use Blender (or your favorite 3D app) up front, more for pre-viz than for CAD/CAM work.
  12. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    Thanks, Rodent. I do appreciate what you're saying. And I do believe that there are tasks in life where it is best to learn how to do it by hand first.

    Unfortunately, your plan would cost me a lot of money I don't have to buy a whole lot of tools I don't have. Or I could spend less money and rent time at an equipped shop (or so I understand - I have not looked around locally). Or I could spend maybe even less money and do it the really old-fashioned way with manual tools.

    Or, I could spend my time learning the software and the process that I actually want to use. My time is more or less free. So, my only real costs here are the costs of the pieces of wood I ruin by having them milled to my specs and then learning what I need to change in my models to get my milled pieces to actually work correctly. And the cost of the CNC time, which turns out to be pretty cheap (in my opinion).

    I predict the latter to be less expensive in the long run and take me less time to get to the goal of being able to produce a body and a neck that actually work (and work well).

    I've been writing software professionally since 1984. Every generation along the way, there are guys who say "well, you really shouldn't be trying to write applications in C# with LINQ until you've first learned how to write them using C and text files", or, "you really shouldn't be trying to develop applications in C until you've first learned how to do it in Assembly Code first."

    I am not of that mind. :) When paradigms change, I would say to any beginner "forget about the old paradigm and learn your current environment well enough to know how you want your final product to work, then learn the current tools and get busy." And I view the change from hand or power tools in the woodshop to free software and cheap CNC time as a significant paradigm shift when it comes to building solid body guitars.

    I am not a great bass player by any stretch of the imagination. But, I have played enough, for long enough, that I have definitely developed specific preferences in feel, tone, looks, and playability. So, I think I will stick to my plan of learning the tools and the process that are the ones I actually want to use long term, rather than spending a lot of time and money learning tools and a process that I plan to ditch just as soon as I've gotten the hang of them.

    Maybe it's also relevant to add that I've done a decent amount of basic carpentry over the years. And I've been roadracing motorcycles on and off for over 20 years, doing 90% of my own wrenching in that time. So, I feel pretty comfortable with tools and basic fabrication so that I at least know the right questions to ask to be able to put together a design that can be CNC milled and will work.

    Do I think I will nail it on the very first try? NO, not at all. But I do think the iterations of refinement required to end up with something that "nails it" won't be too many. And the wood and CNC time used in that process will still be way less expensive than what it would cost me to learn to do it by hand. And with the benefit that once I get that first one nailed, I won't then be going "okay, I know how to do it by hand now. But now I still have to go through the whole learning process for translating a design I can build by hand into a design I can have CNC milled."

    I may be completely naive here, but I feel like solidbody guitars, as an industry, are at a point sort of like the printing/publishing industry was when cheap laser printers first came out. Suddenly anybody could self-publish. I have this vision for myself of getting to a level of mastery with the modeling software that I could go from an idea or a sketch of a completely custom-shaped guitar or bass (including custom neck profile and custom headstock) to a 3D model in software to parts ready to assemble to finished, assembled and playing it in a matter of a few days (not counting the time it takes to do the paintwork).

    Whew! Sorry for such a long post. And I know it comes across as a close-minded know-it-all. I guess it was really just a long way of saying that I have not understood, from what you said, how learning to do it by hand is really going to help me learn to do it by modeling and CNC milling. I know what I want the final product to be. My playing experience will tell me whether I produced it or not. But, knowing how to cut out the shape with a bandsaw or how to route the pickup cavity by hand, well, I don't see how that is going to help me know how to draw it in modeling software to have it milled and come out the same.
  13. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    And, like I said, I am pretty broke these days, so money for tools to do it by hand isn't really in the budget. I'd love to have them and learn how to use them with skill. And I will at some point. But then it will be for the satisfaction of what I create with my own two hands, rather than the satisfaction of what I create with my mind and the satisfaction of playing something I designed, had manufactured, and assembled myself.
  14. Very very cool. I'd love to see what kind of design someone who wasn't thinking about wood working tools and standard practices could come up with.

    I'd also love to see CNC combined with modern printing technology.
  15. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    Did you see this?
  16. pnchad

    pnchad Supporting Member

    Nov 3, 2005

    I have discussed the CNC work with providers - a 'one-off' is probably not cost effective but a run of 5 or 10 would start making sense

    I have a decent wood shop and I use Autocad every day for work (2D only though & would need 3D practice)

    so, I'm thinking about building the prototype physically until design is solid, then do the 3D fab drawings for CNC

    I wish someone (and maybe someone does) offered 3D digitizing so that the prototype could be scanned and then tweaked in CAD
  17. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    There is a tool, I think it's part of the 123D suite that claims to let you turn photos into a 3D model.

    Also, just FYI, I've already found a CNC shop that charges no setup fee and they have a picture of a guitar body that they did that is complete with neck pocket and pickup routes. It cost $100. That sounds way more cost effective than making prototypes by hand and then still having to do one, two, or maybe even three prototypes on the CNC to get the programming dialed in.
  18. StuartV

    StuartV Finally figuring out what I really like Supporting Member

    Jul 27, 2006
    Manassas, VA
    Though, I guess if you already have your woodshop, prototyping might be better off done by hand. Depending on how radical your design is, anyway. If you're just doing a slight variation on a P or J, then I wouldn't see doing that.
  19. Yup. I'd dig it more if it wasn't an LP shape, but the "hollowness" is pretty inspiring.

    As in, you can do some pretty cool things with printing that would be prohibitively challenging in wood.