Thicken issue
Accepted solution
Did you strip this design of the timeline, or did you design it without it enabled ?
This makes it often very difficult to evaluate problems and frankly I cannot be bothered too much wit such designs as I provide help here on the forum voluntarily.
It would seem to me the the fillets on this lofted section are much smaller than the thickening you are trying to apply. What would happen to the surface ? Would you want a sharp corner instead of a fillet ? How would Fusion 360 know that ?
Also, I would never create such a loft. It is better to make the loft with sharp corners and the fillet the corners. This generally crates much cleaner geometry.
The curved rails should not be a problem. Not knowing how this will actually be manufactured I'd say you should be fine with applying fillets externally as wells internally after lofting.
Accepted solution
Alberto, I went ahead and modeled(with history turned on) what i think you were trying to do. Based on the midline seam i would assume you are trying to mold these pieces. There are a few key things that help the process you are doing here. When i modeled the part for you i did the outside shape and inside shape using different methods so you would have both as a reference. Here is some general info for you.
1. When creating lofted bodies, my preference is to use surface edges as references and either a Tangent or Curvature constraint on that edge. With your model i did this for the inside using a squared off sketch and applied a variable fillet to the lofted surface. For the outside i used the same process but lofted based on edges that were already rounded.
2. I opted not to thicken this for a few reasons. Thickening a surface will add material normal to the curvature. Since your part was mating up with other surrounding geometry i created a surface offset of that surrounding geometry and then build the inside and outside and stitched all the surfaces together. As long as you create a closed volume of surfaces this will turn it into a solid.
Take a look at the file and pick back through the features and let me know what questions you might have.
Peter, the surfaces he had were intended to be thickened outward based on the model he supplied. Small fillets on that internal surface would not go away in this manner as he is increasing the radius, rather than decreasing it til the point they disappear. I understand you are trying to help but your comments about you can't be bothered with such design isn't constructive. If you had simply left it at "this makes it harder to evaluate the problem" it would have been more constructive. People come here for answers and to try and learn.
I think your comment about being better to make a loft with sharp corners and then fillet is subjective. That is not a universal thing and for designs that are "curved" i generally avoid true fillets with constant radius as this is not ideal for A side finishes on plastic parts. The transition to a constant radius can be seen in reflections and how light hits parts. It is always important to consider the manufacturing methods, as you mentioned, and intent of the part of course, but I would caution the use of a blanket statement like that. My workflow and preference is to use fillets on prismatic parts intended for machining but manually creating transitions for parts intended to be molded or printed. Again this is my workflow and not universal.
Here are some sample images of what i am describing. The same starting set of curved surfaces. One with a constant radius fillet and the other with a loft using a curvature constraint on the edges. On the one with the fillet you can see the light stop at the edge and also see a dark shadow on the right side.
@MattPerez314 I am curious. When you step into a forum where you have not participated and so far not contributed much at all, what sort of homework do you do before addressing another user ?
I tend to look to look at the number of posts they’ve made, the solutions they are provided and what fora they’ve answered to. I often do a good bit of research to get at least a minimum glimpse at what person I might be talking to.
You evaded answering my question. If you do some research before posting then we can avoid such situations in the future. That indeed takes some time but its well worth it!
In general it might simply be that we communicate differently. I did not mean to cut you or the OP down. I am, however, pretty frank! While I've lived and worked in the US for 20 years I am a German native and grew up around coal miners and steel workers. Hardy folk, not easily insulted but a bit rough around the edges in times 😉
@Anonymous wrote:
Thanks for feeding this forum with your expertise! Hope to be able to contribute soon.
I would encourage you to do so and please don't let other's expertise intimidate you!
If you see posts and feel you can help, just respond. Or simply take the problem presented as a personal challenge and see if you can solve it. I personally find helping other to be a very efficient way to learn myself. Often our work is limited to a particular area and if we only ask questions to get our own problems solved we are limited to solutions in just that space.
However, helping other users with their problems really increases ones exposure to a broader range of problems and increasingly solutions.
Accepted solution
When I initially looked at this design I only took a quick look at the loft and mentioned that lofting it that way can create problems. I took a deeper look at this design over the weekend and here are some findings and recommendations.
In summary my advice would be to consider this an experiment and prototype. Once done with getting the basic shape / 3D model I would start this completely from scratch!
Here is why:
1. Origins are an essential element in any CAD and 3D modeling attempt regardless whether CAD, Sub-D or Sculpt application. In this design the main origin is locate =arbitrarily and is not really referenced in any sketch.
2. Many of these sketches are not fully defined meaning not all of the sketch elements are turned black. Assuming that this design had a timeline it is very easy to destroy by accident. That is particularly true for Fusion 360 as unconstrained sketch elements can be drag-moved in the viewport even when not actively editing a sketch. That can be used to great effect when trying fo find and fine tune a shape for a design, but that ability goes along with some danger and should not be taken lightly.
3. Fillets in sketches are to be avoided if there is a solid feature, which the resulting 3D fillet can be modeled with. Not only does that speed up the sketch process and makes sketch more stable, it results in a more stable design. In my attached version I removed the fillets and swept/lofted sharp edged profiles.
3. The workflow used in this design is rather non linear and experimental and that is also likely the reason there is so much unnecessary construction geometry in it and so many unneeded sketches. I've attached my version of the design. When done properly with that workflow requires only 4 sketches the large and the small inner profile and the 2 paths for the 2 sweeps.
Then these two swept surface bodies are connected with one loft either tangent (G1) or curvature continuous (G2). I used tangency in the attached design. You need to loft between edges, not sketches to get the G1/G2 options.
This results in three bodies, which are then stitched together.
Then the entire structure can be thickened without any problems in one shot!
Finally the edges are filleted with a variable radius fillet.
That is the workflow I had in mind when initially looking just at the loft, but your fragmented workflow makes that very tedious at this point.
The reason why I suggested first lofting without fillets (not sure I ever said it, but that's what I was thinking) is that it creates much cleaner primary surfaces. Here is your loft shown with the curvature map.:
Here's my version created with the workflow described above:
