Best practices

[Anonymous]

I am a guitar maker trying to switch from paper to Fusion 360. I am wondering what my best workflow is. I have some components that stay the same from order, or I should say they are mostly the same. For example, I make anfingerboard that has the feet spacing slotted in. The thisckness is always the same. However, depending on the neck shaping I might cut into the bottom of the profile slightly. How do I merge the component based on a slotted trapezoid into a neck that blends the bottom into a shape?

[Anonymous]

Here is an example, I make a peghead template and that defines a specific cut. After the assembly I shape the neck. The back of the peg head is modified to blend with the neck. This blend is dependent on the neck shape. I am struggling with making the loft. And getting it to modify the peghead component.

[jeff_strater]

Hi @Anonymous,

Great to see yet another guitar maker in the Fusion family!  Shameless self-promtion:  guitar-design-and-manufacture-using-fusion-360-and-cnc.  Except we only did the body, and used off-the-shelf necks...  You are at a whole different level.

For your fingerboard workflow, right now there is an unfortunate limitation that you cannot insert designs from different projects.  That is in the process of getting fixed even now, but isn't quite ready for release.  In the meantime, I would recommend that you just have a single project for all your guitars, and make a folder in that project for each actual guitar design.  You can then, also have a folder for all the common components you need, such as your fingerboard (and any common hardware, etc).

When you start a new guitar, and you want to place a fingerboard in it, insert the fingerboard design into your model, then select that component in the browser, right click, and choose "Break Link" (assuming you want to edit that component in this design).  That will (as the name implies) break the link to the source fingerboard model, so you can edit it and only affect the version of the fingerboard in this design.  The downside is that the link is broken, and any updates you make to the original fingerboard will not be propagated to that model.

Hope this makes sense.  If not, let me know, and I can illustrate with a screencast.

Jeff

[jeff_strater]

OK, maybe I misunderstood your question.  Are you really asking how to blend a headstock into a neck shape?  I have had some experience there (but, mostly I stayed away from neck modeling), and I can tell you that there is something about that geometry that is pretty hard.  You can get there, but it's a challenge.  Some people have had success using Sculpt for this transition.  You can make Loft work, but it takes some fiddling.  Do you have a model you can share?

Jeff

[Anonymous]

Well, to be honest, I have three questions.

1. How to I make stock components where I can break the dependency.

2. What is the best strategy for blending the round of a neck into a fingerboard and finally...

3. What is the best strategy for blending a neck to a heel and/or peghead?

[SaeedHamza]

Hi,

Could you please attach some pictures of the body you're trying to achieve, different views of it if possible

Regards

Saeed

[Beyondforce]

Hey @Anonymous,

If you could make a screencast and explain us exactly what you what to achieve, it will be much easier for us to help you.

Cheers / Ben
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[Anonymous]

The model I am working on is overly complex to use as a teaching example. I'll sketch up a model that could be an open source neck for @jeff_strater s project. It's a quick draw for me and then we can leave a public example for any guitar maker in the future.

[Anonymous]

Okay, I made the start of a file. It should be compatible with the range of stock bolt on guitar bodies for sale. I have three drawings to start. One of the problems I have is indexing work planes to each other. These three sketches should be tied together but they are placed close by eye. Is there a way to snap across work spaces? The next two drawings will define the next shape but I was hoping I could get someone with more CAD experience than I to open the document and help me make sure I am ready to move to the next step. Once I understand how to make workplanes linked together I need to make the pattern for the bottom of the neck to body joint with the 4 holes, the two neck templates to define the neck shape then the real work of trying to blend the shapes together can start. 

In the early 90s I was consulting with Taylor guitars and one of the projects (not mine) at the time was they were producing the acoustic necks CNC. I remember Bob saying that it was faster to carve a neck and bump it in than to draw it. I hope I can draw it as I make every neck profile specialized to each customer.

[jeff_strater]

Hi @Anonymous,

Thanks for posting the design.  Let me make sure I understand the question.  "These three sketches should be tied together but they are placed close by eye".  The main mechanism for linking one sketch to another is to use the Project command.  In your case, you started with the fingerboard sketch:

That's certainly a good place to start.  Your next sketch is the neck profile sketch.  If you want to make sure that the profile matches up exactly with the fingerboard, the best way is to project geometry from the fingerboard into the profile sketch - probably the start and end points, as those seem to be the critical pieces.

Here's a quick and clumsy screencast showing how to start this:

But, the other thing I would challenge you to think about, before you get too far,  is how to structure your components.  Offhand, I suspect that you will want separate components for the fingerboard and neck.  You can drive all of these from sketches at the top of your design, like you have started.  This technique is sometimes called 'skeletal modeling' (because the design is driven from one or more top-level skeleton sketches.  But, that will mean that both of your neck components will be in one design.  This, of course, is not a problem, but in your original post, you mentioned that you want to have one reusable fingerboard component.  Having the neck and the fingerboard in one design would prevent you from doing this.  Now, instead, if you want to use the skeletal modeling technique, your template design can just contain the sketches and the fingerboard and neck itself.  Then, you can copy this design for each guitar you design, and tweak the profile, width, headstock shape, etc for each custom design.  Just something to think about once you get the mechanics of the actual modeling worked out.

Jeff

[Anonymous]

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@jeff_strater wrote:

But, the other thing I would challenge you to think about, before you get too far,  is how to structure your components.  Offhand, I suspect that you will want separate components for the fingerboard and neck.  You can drive all of these from sketches at the top of your design, like you have started.  This technique is sometimes called 'skeletal modeling' (because the design is driven from one or more top-level skeleton sketches.  But, that will mean that both of your neck components will be in one design.  This, of course, is not a problem, but in your original post, you mentioned that you want to have one reusable fingerboard component.  Having the neck and the fingerboard in one design would prevent you from doing this.  Now, instead, if you want to use the skeletal modeling technique, your template design can just contain the sketches and the fingerboard and neck itself.  Then, you can copy this design for each guitar you design, and tweak the profile, width, headstock shape, etc for each custom design.  Just something to think about once you get the mechanics of the actual modeling worked out.

Jeff

Thank you Jeff, This is exactly the type of advice  am looking for and why I named the thread Best Practices. I'll dig into it and post a new version of the file.

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[Anonymous]

Okay, I am not sure if I fully understood everything you were teaching me but I did learn some of it. Here is the updated drawing. A loft between the two neck profiles makes the shaft of the neck an easy object to create. However before I start making bodies I was hoping you could review the sketches and see if things are in the right planes etc. For instance, would it be better for me to make an offset plane for the back of the peghead and put the sketch there? 

[Anonymous]

I forgot to include sketches for the fingerboard radii. Traditionally a fingerboard would have about a 15" radius cut across it to make it more comfortable. As time went on and string bending became common we learned that a string will "fret out" and get dampened on the frets if the radius is not compound. This was especially true of the 12" radius necks that became popular in the '80s. The solution was to make a compound radius. 12" at the nut and 17" at the heel was common. With CAD I was able to calculate it more precisely and that is included in the two added sketches.

[jeff_strater]

Hi @Anonymous,

You are definitely headed in the right direction, this version looks pretty good.  A couple of comments so far:

1. In the "Neck Shape Peghead End" sketch, your profile is not completely closed:
   
   
   so, you won't be able to do the neck loft until that is fixed.
2. I played around with your earlier version.  I think one challenge, modeling-wise is going to be the transition from the curved portion of the neck to the rectangular area that sits in the body neck pocket.  I've found that one to be a challenge to get exactly right.  I haven't yet come up with the perfect way to do this.  Let me know when you get there, and maybe we can work out the best approach.
3. I started down the same path as you did - to model the whole neck, and the same approach of using sketch mirror to get the symmetry.  However, thinking about it more, I might try to do this as a "half model" - just build one side of the neck, then use solid Mirror to make the other side.  It doesn't really matter too much, but this might make your sketches simpler.  Just something to consider.
4. Regarding the fingerboard radius.  Fusion should be able to handle this fairly well.  You can either over-build the fingerboard, then loft from the 15 in radius to the 12 in radius as a surface body, and use Split Body to trim off the unwanted piece (somewhat analogous to the way it's done in real life).  Anyway, the geometry should be something that is easily done in Loft.

Keep asking any questions that come up.  I'm traveling this week, but will have some time to respond.  I have lots of interest in this project, so I'm willing to help where I can.

Jeff

[Anonymous]

@jeff_strater Thank you so much! I have been drawing and re-drawing all day. I have created and deleted many sketches. I have sorted out the lofts mostly after making lots of planes. I am sure I can even do an acoustic heel. However I seem to have broken the file. The surface between the Body Attachment and the Body End Neck Profile dos not think it is a continuous plane and I cant figure out why other than there is a dependency somewhere leftover from something deleted.

[jeff_strater]

Yeah, I noticed that one myself.  The root cause is that the sketch lines in the sketch that generates that feature are not colinear.  The fix is to add that constraint:

However, fixing that only partially fixes the problem I mentioned before:  That transition between the part that fits into the body slot and the round neck.  Another post coming...

Jeff

[jeff_strater]

Once I fixed that problem, I tried to do the loft between the two sections of the neck.  The default results were horrendous:

At first I thought it was this fillet:

So, I deleted that.  Then, the loft failed completely.  I noticed this small face:

That is probably the source of the problem.  I'm trying to untangle that now.  But, looking back in history, it looks as if you might have tried to create this loft once in the past:

But, things did not line up exactly, and I think a lot of the problems start there.

I would do this in something like this order:

• create the neck loft
• create the heel extrusion
• then, when those are OK, and are lined up, add the transition loft

Once you've figured all this out, it might be worth maybe starting from just the basic sketches again.  I always find the second time I do a design, it always comes out a lot cleaner

Jeff

[Anonymous]

Thank you for sorting that out! I had a perfect loft there but I changed something and lost all my bodies at some point. I am not fluent with the timeline so I did not try to go back I just moved forward. The horrendous loft you had actually fixes well. I don't know why the default is asymmetrical. Yesterday, when I started this drawing, I did not know how to Project and there are lots of points projected on accident and on purpose that are no longer needed. A re-draw is in order. Also, I tried to use mirror as much as possible but I was not consistent enough. It's funny, I have been drawing necks for almost 30 years and I don't even think about it any more. I feel like a student again. It will take me a couple of days to post the updated file. Thank you very much for all your time!

[Anonymous]

I figured out how to make rails to make these lofts like I would carve it but it is tedious and frustrating. I need to make the rails with splines in a 3D edit mode. With enough rails there are some really elegant shapes I can make. The stock loft just uses straight rails. I have having a really hard time making a 3D drawing have coincident points. Any advice on making this faster than making a new sketch plane for every spline?

[Anonymous]

@jeff_strater, I have spent a few more hours playing with lofts. I am confused by points. In this drawing I did not project any points with the project command. Some of these drawings I have mad allow me to slide rails on the profile sketches. I am not sure what makes that happen. Between moving the connection points and changing the curves I can make anything I need. What I really need is to sort out how to make them slide on the profile sketches. I have learned that making the loft before the mirror is much easier to deal with. I know you are traveling. Perhaps you will get a chance to look over this sketch. Or anyone else for that matter. 😉