CAD Practice: Pencil Cup

Continuing with last weekend's practice, I modeled a slightly easier object for today: a pencil holder cup. 

Orthographic 3/4 view.

Orthographic side view.

It's effectively a cylinder so my main method of building this was with revolved profiles and circular patterns. The top and bottom lips were created as 2D profiles at the right radius away, and then revolved about the vertical axis. Nothing too special for these.

The mesh wall is where it gets interesting. I knew there was a coil tool in Fusion 360 I could use to build the majority of the wall, but the problem is that the wall tapers in at the bottom and the coil tool is mainly intended for only areas of constant radius. I first tried creating the vertical part with the coil tool and then projecting the remaining part of the coil along the bottom on a tapered surface. Then to create the tapered coil I lofted a circular profile along the projected path. However, this creates a discontinuity between the top and bottom sections of the coil. I may go back to revisit this method and find a way to join them cleanly but I wanted to create the entire coil in one continuous loft. There is an angle parameter in the coil tool that could be useful.

To get my continuous loft, I created a coil that had a larger diameter than I really needed, then projected this onto a continuous cylinder + taper body:

Oversized spiral + projection.

Zoomed in; I tried to smooth the line with arcs.

Final lofted circular profile over the path.

The final result isn't perfect either, but it is continuous. The smoothing arcs for where the cylinder and taper meet at the fillet were not followed but again it's something I should revisit to get a smoother connection. In the final model the transition corner looks off since in reality the spiral should not get steeper (and this causes there to be an unintended continuous ring of material instead of a mesh).

Finally, I mirrored the mesh segment to get the opposing spiral direction, then circularly patterned the two bodies 60 times to form the final mesh. 

One quirk with this method and my order of building was that I had to join the bodies of the taper and the cylinder to get the fillet and the continuous projection path. The consequence of this is that when I went to hide these construction bodies they took the upper lip with it (as they are all joined as one body). After the mesh was built I just re-revolved the the lip sketch to bring it back for the final model. Fusion 360 really didn't like me joining all the bodies together with the lip after the circular pattern; my computer froze for several minutes as it computed the join. You'll see that even in the timeline playback the last step hangs for a bit.

Video playing back the timeline:

Final nice render: