How to model a closed helix cap?

[GutenBar]

Today my students brought me a challenge: they needed a model of a cylinder with a top cap in helix shape, like the tip of a drill.

After some failures in Fusion 360, I did it in 3DS Max (figure1.jpg) using a Helix and a Circle with Edit Spline and Surface modifiers.

Back in the Fusion, I was intrigued with this shape, but the solutions I found did not please me nor answer the problem (one through Surface Loft and Thicken, and other with Form - figure2.jpg).

In the end, I export an OBJ from Max, imported it into Fusion and converted it from quad mesh to T-Spline. After some creases, the part was good (figure3.jpg).

So, my doubt is what could be the best way to model this object in Fusion 360?

[KristianLaholm · Accepted solution]

I used Surface-tools and Bouandery Fill creating the Solid.
The Top "helix surface" is created in 2 steps:
* Surface sweep with twist angle (-360deg) creating a helix.

* Loft from helix surface edge to point.

[GutenBar]

I had never noticed the Twist Angle in Sweep.
Perfect solution and I even learned something new. 🙂
Thank you very much!