Inward Fillet in 3D

[-Ryan-]

I'm able to fillet a cylinder's edge.

Fillet, Radius .10

But, I can't get it to fillet backwords. Here's a pic of what I'm trying to do in 3D, three cylinders on top of each other.

How can I get the middle cylinder to fillet inwards?

Here's a look at the idea.

Thanks for your help.

Ryan

[David_W_Koch · Accepted solution]

Are you looking to create something like this?

I am no expert on solids modeling in AutoCAD, but until someone else who is comes along and proves me wrong, I will go out on a limb and state that the FILLETEDGE command will not create a convex fillet.  To create the middle section above, I modeled a cylinder, with the radius as desired at the top and bottom of the final form.  Then I modeled a torus, of the same radius as the cylinder, and with a tube radius of one half the height of the cylinder.  With both pieces' geometric centers at the same point, I then used the SUBTRACT command to subtract the torus from the cylinder. 

The image below shows the cylinder, the torus (separated for clarity), and the result of the subtraction.

You may already be aware of how to do that, and were looking for a way to directly edit the cylinder.  If so, I cannot help with that.

[Anonymous]

David, thanks for your reply.

I'll give it a try, as I'll be wanting to do different sizes of fillets and raise the heights of the middle cylinder. 

[dbroad]

Another option:  Draw a closed profile and revolve it. If it's not circular, then sweep it.

If you have 3 cylinders of different radii, then union them before filleting.  Also, the fillet can't be larger than the adjacent faces.

[-Ryan-]

We did it!

Working with your idea gave completed results. I wanted the indent in the cylinder to be a lot less, so I used two smaller toruses. 

I then filleted the edge and erased the top. The two toruses made a piece, in the middle of them, stick out.

I mirrored the bottom piece and added a cylinder between them, making the middle smooth.

With your method, we succeeded.

Thanks.

Completed image.