Ruled Surface with Draft

[Anonymous]

Hey Y'all,

I work at a Product Development company and we are always looking at the future of CAD.  We currently use Solidworks extensively.  I have been a fan of F360 for many years and have used it on many projects but most would constitute hobby level efforts. I have a few days of downtime and have chosen to recreate a manufacturable computer mouse design (currently in SW format) feature for feature within F360. 

I have been successful through most of the surfacing thus far but I am stuck.  Essentially I trying to model a ruled surface along a complex spline.  I am trying to control the draft angle of the surface.  See SW screen cap below.  I have attempted to extrude it (but adding a taper angle causes it to fail), loft it (but the surface ripples in areas), and sweep it (I am unable to properly control the draft angle.) Looking forward to hearing from this great community. 

[TrippyLighting]

Looking through your model I would not advise to use T_Splines this way. Did you check the curvature on any of the edges create my cutting away on that T-Spline ?

It might work at the moment, but the more you wok on the model, the higher the chance will be that his will interfere  from filleting, shelling, thickening or offsetting surfaces.

[Anonymous]

Hey Peter,

Thanks for the reply.  You contribute so much to this community, it is hugely appreciated.

As far as the surfacing goes, I did not use T-splines (as far as I know) to generate the surfaces.  All of the work was done in the surfacing workspace.  I have attached the surfacing master.  If Fusion is converting surfaces to t-splines or certain patch commands are actually using t-splines under the hood that is news to me.  

I appreciate the focus on curvature.  About 2/3 through the timeline I deleted faces on the thickened surface that Fusion had generated and patched it with a single surface.  I believe this is partly the cause of the issue you highlighted.  

[TrippyLighting]

Ha, I was fooled by the naming of your file and the curvature problems 😉

I connected the wrong dots!

The reason for some of the curvature problem is - if I can trust the naming of your sketches - that you are working with intersection curves. Those often create curvature problems. It is indeed more reliable (in Fusion 360) to extrude and trim surfaces and work with the edges created by those operations instead of an intersected or projected curve.

While working with your file I also discovered a bug you may, or may or may have noticed yet.

[Anonymous]

Ahhh, I did indeed use intersection curves.  I understand your suggested solution and will implement it in general.  My original question still stands.  After I fix the base curves and surfaces is it possible to create this drafted surface?

Good catch on the bug, I missed it.  I caught a different one but that is a story for a different post. 🙂

[TrippyLighting · Accepted solution]

Yes, I'll have to look into this sometime this week.

However, his shape is pretty complex and I am not sure I would attempt surfacing this in Fusion 360, or at least not by replicating a Solidworks based workflow. I never did any surfacing in Solid Works in the 15+ years Ive worked with it but I firmly believe that Fusion 360 does not yet have the depth of tools Solid Works has to offer.

Also, Fusion 360 has a number of debilitating bugs when it comes to spline handling in 2D and 3D. At some point in time you'll need a 3D blend curve and might run into this problem, or this problem, or some others.

I run into these frequently.

Don't get me wrong, I do believe that there are many things that can be done in Fusion 360, but this isn't one of them. You might get lucky and it does not interfere with your design. But it isn't at a level yet where I would consider it reliable enough for professional Industrial Design and product design work.

[Anonymous · Accepted solution]

Adding to this thread with hopes that it might help someone else.  With the addition of Ruled Surface in the latest June 2020 update, this is appears to be the correct solution to this problem.  I quickly attempted to create a drafted ruled surface with the complex spline as the root geometry and it appears to have done a serviceable job.  

@TrippyLighting In re-reading your post a new question came to mind.  What is your go to surfacing tool?  (I might guess Blender given your replies  in other posts)

[TrippyLighting]

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@Anonymous wrote:

@TrippyLighting In re-reading your post a new question came to mind.  What is your go to surfacing tool?  (I might guess Blender given your replies  in other posts)

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I do use Blender a good bit in conjunction with Fusion 360's T-Splines but would not say that it is my go-to surfacing tool. The reason I use Blender for modeling instead of T-Splines is because it has an incredible set of modeling tools.

I would say for the most part I use T-Splines when I don't have to cut it apart later using surfacing or solid modeling techniques. Smaller detail such as holes are fine, but I try to avoid creating a single shape using T-PSines and NURBS surfaces.

The computer mouse model in this thread I would try to model with surfacing tools, not T-Splines.

The Fusion 360 team continually improves the performance of the surfacing tools to create better quality surfaces.

There are still a good number of bugs in the sketch engine to be ironed out and it's more like an ultra-marathon than a sprint 😉