"Extrude" clircle to smaller circle

[liviuslivius]

Hi all

i am begginer in Fusion 360 but i have looked at realy many tutorials and i did not found a way to do what i want.

I Suppose it is basic operation and should be simple.

I need "extrude" circle to smaller circle.

E.g. bottom circle is 60 radius outside and 50 radius inner, top circle is also 60 radius outside but inner circle must be 35. 

In extrude/pull option i see only tapper angle but its result is chnged also outside circle and i do not need to gues which angle i must use. How to solve this as i have many parts as this to create.

Please help 🙂

[seth.madore · Accepted solution]

What you are looking for is a Loft.

Create a sketch with your OD and 35mm bottom diameter

Extrude up 80mm

Create Sketch on top of part, drawing your 55mm diameter

Loft between top sketch and bottom sketch

File attached 🙂

[liviuslivius]

Thank you very much. I miss this basic thing.
All tutorials show loft on rectangle and circle but not on more complicated things with wall width like donuts 😉

[TheCADWhisperer · Accepted solution]

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@liviuslivius wrote:
 I miss this basic thing.

@liviuslivius 

Always use the most primitive computational solution - in this case Revolve.

See Attached.

[liviuslivius]

I see i must change thinking about gemoetry. You simply create two e.g. rectangle, and draw 4 lines, delete rectangle and finish scetch and then resolve by axis?
It works well.

You mention that it is less computional. What do you mean here and can this also affect 3d print also?

[TheCADWhisperer]

@liviuslivius 

Every action has a computation "expense".

Lofts are more "expensive" to calculate than revolve.

For a simple part like this - you would never see the difference, but as your designs become more complex the interaction between features can really slow things down if the features were not created with the most efficient technique for the software to calculate.

In general - if you think about how you would manufacture (out on the shop floor - not 3D printing), that is probably how you should model the geometry.  This geometry would be turned (Revolved) on a lathe.