Making 3D fillets (aka rounded edges) on 3D objects with curved shapes

Is there an "easy" way to fillet the edges of a 3D, curved object?

In this case, I'm looking at making a couple machine parts (I usually have
done architectural stuff). The shapes are easy enough to draw and extrude
BUT the edges must be rounded off.

I can't simply create a section and make it follow a path, since the pieces
are not even in size as they bend around the various curves. Also, simple
booleans won't work in these cases to do a "subtract" from the edges,
because of the curves.

Now, I know ACAD is used often for mechanical purposes so people MUST have
encountered this in the past and there must be SOME way of dealing with it,
without a herculean effort of 3D modelling.

Are there techniques for doing this? Commands I'm not familiar with?
Routines or add-ons?

Also, if readers here don't know, might there be a better place to post this
particular question?

Thanks!

 

UPDATE:

OK, I found just how easy it is to fillet 3D shapes. I'd just never had to
do that before.

HOWEVER - it does not work right.

Using simple straight edges or some curves, it works great. But I had
created a shape out of 4 arcs connected in a closed polygon and extruded.
Every time I tried filleting the "end" arcs, I got an error, "failure to
create blend, failure to create fillet".

This is a simple geometry and I can't see why it would fail.

Any suggestions to make it work?

 

you'll probably get more replies on alt.cad.autocad

Shaun

 

OK, thanks. always good to know where to post.

Do you also know of any good discussion boards / blogs on autocad where a
lot of expert users hang out?

 

Hi,
I am not able to send the file. The mail is not known to me.
Pl. see the attched dwg. It may be solve your probem. If not pl. send
me some pictures of your model. I will try to solve.
Some times autoCAD can not fillet because the operation may be
disturbe some other faces or the operation request to add some solids
on the model. At that time you see some failure massage in your
command prompt. Pl. find the dwg it will help you.
Thanks
Ananta