topic Re: Ruled Surfaces and Fusion 360? in Fusion Design, Validate & Document Forum

Ruled Surfaces and Fusion 360?

Anonymous — Tue, 06 Feb 2018 18:16:45 GMT

I'm investigating different CAD software programs. I'm not sure if Fusion 360 suits my needs...

My plan is to create some relatively simple shapes to be machined from wood. I am planning on designing with convex ruled surfaces for all of the surfaces of my shapes. By using ruled surfaces, I figured that the end or side of a regular square end mill bit on a 5-axis machine could efficiently carve the ruled surfaces without needing many passes to make perfectly smooth surfaces. With convex surfaces that are more curvy like a portion of a sphere's surface, it takes many tool passes to approximate the intended shape. The more passes, the closer the resulting carving is to the intended shape. With convex ruled surfaces, I expect that just a few passes can carve the surface exactly.

I've attached a picture with an example of the type of convex ruled surface I'd like to create. The two defining lines are different. In the example, one is a straight line and the other is a semi-circle. I could also use two semi-circles of different sizes, or two different arcs, or even two irregular spline curves...as long as the resulting ruled surface is convex.

Is my thinking correct?

How do I create ruled surfaces with Fusion 360?

Can Fusion 360's CAM compute efficient tool path's for ruled surfaces like I'm describing?

If Fusion 360 cannot do this, which software should I consider?

Thanks!

Re: Ruled Surfaces and Fusion 360?

TrippyLighting — Tue, 06 Feb 2018 18:27:08 GMT

You'd use the loft command in the Patch environment for this if you really only would want surfaces. It might still be what you need depending on the complexity of these surfaces.

However, you can also try the loft command in the Model work space

Re: Ruled Surfaces and Fusion 360?

Anonymous — Tue, 06 Feb 2018 18:38:31 GMT

Thanks, Peter.

Because FreeCAD has separate tools for ruled surface and loft, I didn't think loft was the right tool for the job.

Ultimately, I want to have 3D solids with ruled surfaces. I was expecting that I could define a ruled surface with two curves and then use the resulting surface to cut a primitive solid like a cube. Makes sense or is there a better way?

Thanks!

Re: Ruled Surfaces and Fusion 360?

TrippyLighting — Tue, 06 Feb 2018 18:42:23 GMT

That is certainly an approach that is often used in product design where such ruled surfaces are overbuilt (extend beyond the actual geometry you want to build ) and then trimmed to enclose the final geometry.

But sometimes its also easier to simply define two cross sectional profiles and simply create a solid oft.

Which of these two is the precut approach depends on the details of the model you want to create.

Re: Ruled Surfaces and Fusion 360?

Anonymous — Tue, 06 Feb 2018 18:51:11 GMT

Well, it seems I should give Fusion 360 a try for this. 🙂

Thanks to your direction to loft, I just watch some youtube videos. It looks like if the termination condition is "free" between two sketches then the loft is guaranteed to be a ruled surface. Is that correct?

Re: Ruled Surfaces and Fusion 360?

TrippyLighting — Tue, 06 Feb 2018 22:20:19 GMT

I believe so.