Advanced Loft question

[jtylerwaller]

Hello,

I first must tell you that I am a self taught beginner with Fusion 360 and 3D design in general. I am a High School technology teacher that is starting a STEM guitar building program at my school this year. I have been chugging along and learning the Fusion work space very well, but I have ran into a a problem that is causing me some trouble. I have created a general design of a guitar neck and have successfully completed the project using a CNC router. However, I wanted to create a more well sculpted neck to aid with finishing and that would require less sanding after coming off of the Shopbot. I have created the basic shape but can't for the life of me get the neck profile on the back to loft to where it meets the head stock. I am fully aware that this is a copyrighted headstock design from Fender and I will not be using it as our final design, but simply using it as a building block to secure the knowledge required to finish the design.

any help would be greatly appreciated.  

[SaeedHamza]

Hi,

Could you please provide a picture of the guitar that you want to create

Regards

[jtylerwaller]

I'm attempting to similarly create this style of transition from the headstock to where the neck profile stops..

[SaeedHamza]

Could you please attach the file

go to file > export > .f3d and attach it to your next post

Regards

[TrippyLighting]

You should probably read this fairly recent thread that not only also involves modeling of guitars but contains some excellent advice on lofting and use of T-SPlines for such purpose.

[jtylerwaller]

Here is the file

[jtylerwaller]

I'll read through this thread. Thank you for the info.

[TrippyLighting]

OK. Was that before or after posting this thread ?

Also, you do realize that what you designed is a mirror image of what the photo shows ?

[TrippyLighting]

Looking at tis further, your sketches are very under defined, meaning there and dimensions on it and too few constraints for this to behave stable.

Before looking at such advanced topics such as lofting, yo'll find references to that in THAT thread as well, you really should spend some time getting sketching correct.

That should not really take  long but you'll save yourself many headaches down the road if your sketch is solid. Constraints are your friends and ensure that the shape of you object is maintained even I you adjust dimensions.

[SaeedHamza]

I tried a workflow and got this transition, is it close enough? ( File is attached )

[TrippyLighting]

If you use a variable fillet radius and make it bigger toward the neck that blend should actually look quite well!

[SaeedHamza]

Can't do that, because I used a loft with both profiles set to tangent, so I can't use fillets on them, it won't even let me chose them to fillet them

[TrippyLighting]

Can be done if we take a little creative freedom.

[SaeedHamza]

Oh, yes this originally was done as a fillet

I thought you were talking about these edges

[TrippyLighting]

Here's my approach to loft (patch environment) the heel. It needs more work but I'll refrain from further work. The heel, which should be symmetric is not because the sketch is not properly constrained.

[laughingcreek]

The biggest pitfall I've seen so far with doing lofting work on guitars is, by far, the insistence on using imported curves to produce the geometry.  Sometimes it's because the user wants to stay "true" to a design they purchased, or because they fell in love with a  set of curves lovingly drew in another program (a program that was, no doubt, lodes better at curve creation than fusion).

Unfortunately, these beautiful curves turn in to garbage when imported into Fusion.  you cannot count on endpoints to be coincident, curves to be tangent.  Seemingly straight lines might have a really short bit at the end that keeps chain selection from working for no obvious reason.  The list goes on.

This even happens with lines curves imported directly from AutoCAD.  I've had discussions with AD about this in the past, but they didn't seem to really see what the issue was at the time.

The only solution I've seen so far is to redraw any curve that will be used for lofting, so you have clean geometry.  This goes for curves that you loft directly off of, or curves that create an edge on a surface or solid that will be used while lofting.

The loft it self isn't going to be particularly difficult.  you may have to cut some of the surfaces back to create room for the loft to transition the way you want.

[cekuhnen]

@laughingcreek I think there are often points AD seems not to understand or maybe they cannot do much about it.

Over the past years I found multiple situations where logical choices where not made because it was not evident to them.

However regarding curves in general I do not understand why people import curves - it must be an understanding issue

as there are no benefits for doing the curves in an external app.

The only are in my professional work I do that is when I do architecture work. But for everything else in the main CAD

application I create the curves as needed.

CAD apps offer curvature graphs AI and such do not so there is no point in using AI.

Fun fact some of my past students after being frustrated with AI rather do 2D sketch work in Rhino and then export it to AI for coloring them.

And with Fusion featuring a parametric sketch engine you even more want to hand make your sketches.

[cekuhnen]

@jtylerwaller

Hey fellow educator - if you need some help ping me.

[jtylerwaller]

Thanks for the help everyone! Like I said, I knew that I didn't have a clue what I was doing when I started on the design of the neck so I figured I was going about it all wrong. I understand the basics of CAD and 3D design, but am not even close to proficient. One of the major issues I'm having is trying to understand the sculpt environment. I'll spend some more time the next few days trying to learn more about it. Correct me if I'm wrong, but it seems as though that is the place I need to be working. 

[jtylerwaller]

Saeed,

Could you possibly step me though how you came about that design? I want to make sure I can learn the concept as I will be able to tweak my design in the future if I do.