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?

[jeff_strater]

Hi @Anonymous,

I took a quick look at this.  Basically, it comes down to the order in which you create the sketches.  Take a look at this thread:  lofting-and-projection-include, especially the 3 videos I posted there.  Basically, you can do this in one of two orders (there are other combinations, but these are the main two).  Either you create the profiles, then fit the rails to the profiles (using Project or Project Intersect), or you go the other way, and define the rails first, and fit the profiles to the rails, again using Project or Project Intersect. Using the first method (profiles first, then rails), you can adjust the profiles, and the rails will update.  If you do it the other way (rails first, then profiles), then you can adjust the rails, and the profiles will react.  I'm trying to find time to turn the videos I posted in that thread into a Knowledge Base article on loft, sketches, etc.

One question back to you:  You have one sketch for "straight lofts", then you define a sketch with 3D rails.  Did you use Project Curve to Surface to construct those?

Also, you did use Project in this sketch.  In the "straight lofts" sketch, you do project the curves from the profiles into that sketch, and the straight lines are made coincident to that projection.  And, mostly, these rails update as expected.  However, you can see in this screencast that one set of rails does not update.  This is because that coincident was not established between the straight rail and the projected curve from the profiles.

If that referenced thread is not understandable, I am happy to try to explain further.

Jeff

[Anonymous]

Hi @jeff_strater, I had written a reply to this but I see it was not posted. I created the straight rails in order to make construction planes perpendicular to the tangent of the shape. Once this plane is made I project to points from the end of the straight lines into the new construction plane and make a spline curve. This does two things for me. First it makes sure the rail don't throw an error when I go to loft. Secondly, it mimics the way I actually carve these shapes in real life. To cut that curve I use a half round rasp and work on the tangent with it. With 6 splines I have been able to get some decent shapes that will cleanup in the final sanding. I have cut some necks from 2x4 scraps this week and I am getting close. 

I ran into another thread here where someone is using t-spline in the sculpt environment to do the same task. I will explore that in some sample files to see if it is better I have been tring to do the zebra analysis to better see what is happening but so far I have not found it terribly useful. I must not understand it yet.

[Anonymous]

Hi @jeff_strater, I spent most of the night drawing and re-drawing the neck. I tried to make T-Splines work for a long time and while interesting I did not find them time saving or particularly convenient. In the end I ended up going back to solid lofts. I really like my idea of making an angled construction plane for each spline rail. It saves me time in the long run. Also, it is very important to have the neck end of the spline tangent in line with the neck shaft. I cut 4 necks and I am certainly withing a quick hit with a rasp or sandpaper wrapped around a dowel. I am ready to start on the neck I need for my customer. Here is the file. It needs the fret slots made and projected to the FB surface. I made the first fret at .023 wide. It could be pressed onto the FB now. When I have a moment I'll press them all and post a final file. 

[jeff_strater]

Hi @Anonymous,

It's looking pretty good.  I agree that Loft seems to be the right tool to use for this transition.  While TSplines can work, they are not parametric, and so won't update if your model changes.

Overall, your approach, especially with the rail curves, is clever, and seems to work.  I did notice one issue with the neck-to-heel transition, and recorded a screencast showing what I found and a suggestion of one slight modeling practice you can try:

Keep us informed of the progress!

Jeff

[jeff_strater]

I fixed up that loft by editing the "Heal to Neck Straight Lofts" sketch, and using "Include 3D Geometry" to include geometry from the faces I want to loft between.  Then, the lofts are created pretty easily, and I am able to add fillets:

Model is attached, in case you are interested.

Jeff

[Anonymous]

Thank you!

I did not realize I could fillet into the lofts. On the router the fillets tend to generate random tool paths but If I made sure it didn't try to do anything but surface the neck mount it would be fine. If I were going to produce an offset peghead I would make the neck to peghead loft asymmetrical but this was really intended as being art that could leave the shop and give me a chance to practice designing 3D shapes in Fusion. I have been working on a few traditional acoustic heels as well. It is so fast for me to carve a traditional heel that it does not pay to use the CNC for it. I am wanting to use it for an acoustic bolt on neck for production where the CNC makes both the neck and the neck block in the body. The shapes are very complicated and don't lend themselves to production by hand.

[Anonymous]

The difference between lofting from face to face and sketch to sketch might also be one of my tool path selection problems. Hmmm.....

[Anonymous]

Last night I tried to draw something I would make. I had to work in both model and sculpt to get there. It was about 5 hours of drawing. About 3 was learning time. Today I carved this:

[jeff_strater]

very nice!  So, you decided to give the sculpt approach a try?  That's good.  I had decent results with it for a carved top body, but where I struggle is in making a transition to an existing solid.

Jeff

[Anonymous]

I am starting with the Basic Electric Neck and using sculpted planes to cut bodies. I remade the neck to peghead loft in sculpt and had a bunch of holes. It was a couple of hours of trying different things. When you look at the model there are lots of pieces and it does not look pretty. But, the nice thing about the sculpt is you can drag the mesh around and you don't have to worry about the lofts lines as much. I have a lot to learn about it still but I can make parts now so that is a big jump forward. I'll play with this neck for a little longer and likely make up a guitar but it will be the first electric under my signature. I make my living on steel string acoustics and I am a long away from making an acoustic neck as fast as I can carve one by hand. The machining time alone is longer than carving it with rasps. I hope to make some parts that are too complicated to make by hand allowing me new design possibilities. 

[mavigogun]

A few things to consider when employing the Sculpt work space:

Edit Form is greatly empowered by creating named views that correspond to your major bodies; this allow you to select "View Space" as the Coordinate Space for the edit control interface to orient to.   Why would you want to do that?   Here, it would allow you to drag an edge aligned to a face in order to smooth or extend a transition without intruding on or distorting existing volumes.

Create finished forms of major geometries by whichever means you prefer, for use with Pull in the Sculpt work space.   Why?  These bodies allow for smoothing of distortions and alignment of transitions.

Use Flatten in the Sculpt work space to align and pull volumes into shape; creating Sketch cross sections, vertices may then be snapped to match.  While the Sculpt work space may not be independently parametric, parametric design in other environments may fill that role, as with the example of Flatten.