When to use Primitive Shapes or sketch the shape?

[JonSchaeffer]

When is it best to use a primative shape like Box or Cylinder?

And when is it best to create a sketch then extrude?

As I design, I am finding that I tend to use Sketch and Extrude to truly define geometry with constraints.

And I tend to use the primitive shapes for things not particularly important to the true design as they only show up in the timeline and not the tree.

Am I thinking corectly? Or could I end up making things harder for me as I design with this thinking?

[jeff_strater · Accepted solution]

Of course, this is a bit subjective, but in my opinion, yes, you are thinking correctly. I also use primitives mostly if I am just trying out a quick concept, and use the sketch/feature combo for more precision.

Underneath the covers, most primitives use these same building blocks. As you probably guessed, a box really is just a sketch rectangle + an extrude. A cylinder is a circle + an extrude, etc.

I do use sphere and torus more frequently, just because setting up the sketch to create these is a pain (you need two sketches for a torus, etc.

The main limitation with primitives just now is that the sketches they are built with are not associative - if you snap to the edge of a face, nothing keeps that edge of the new primitive associated with that edge. This also limits their usefulness. We have a project on the list to improve this.

So, if you are comfortable using sketches and features, I would recommend continuing to use those - you will have more control over your design, IMO.

Jeff Strater (Fusion development)

[JonSchaeffer]

Thank you! 

That was always a haunting question that floated around in my head!

[wadeJ4J2S]

I'm wondering if Jeff's response is still valid, or have the enhancements he alluded to been made?

[HughesTooling]

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@wadeJ4J2S wrote:

I'm wondering if Jeff's response is still valid, or have the enhancements he alluded to been made?

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@jeff_strater  Response is still valid, no improvements made to the primitives yet!

Mark