Adding Fillet to Hollow Loft (using Shell)

test_test395

I am making an air duct, like a vacuum attachment, that is using a Loft to combine a rectangular shape to a circle. 

If I add fillet edges to my rectangle, the loft will not hollow out using 'shell'. See: https://cad.onshape.com/documents/94e7a005797c3fc13cb37889/w/c23e05e46c13d1b0e327721b/e/8c54f43be93fb7452f0ba44f

If I remove the fillets, I can create a hollow loft, but it will give the error ''failed to fillet selections' once I try to add the fillets to the part. 
https://cad.onshape.com/documents/94e7a005797c3fc13cb37889/w/c23e05e46c13d1b0e327721b/e/b70dd9a069d013112d9acf80

I am an absolute beginner, thanks for any help! 

robert_scott_jr_

Hello and welcome. Although you've achieved the part with the thickness you desire, perhaps you'd like a cleaner, smoother look. Take a look at a version of your document; a bit complicated but resulting in what may be a more desirable part. - Scotty

https://cad.onshape.com/documents/86d2f43d26c4f4be42471e4b/w/c26425d30cf0470651179909/e/05ef70c90a1a66db6e309e97

john_lopez363

@test_test395...  this is a very simple fix.   For Lofts to perform smoothly it usually help that if both Loft profiles have the same number of points defined. If they do not Loft will try to figure it out on it's own, and will sometimes guess wrong.

To fix this simply add a "Point" onto the circle sketch that is generally in a location where you'd expect the intersection of the Loft to occur.  Then when creating the Loft use the "Connections" function to define a connection between the Point on the circle sketch and a corresponding Point on the Rectangle sketch.

Test this by clicking the Connections function on your original Loft and you will see how wonky the connections are when not controlled.  By the way, this is also how you purposely twist a Loft if that is what you wanted.

 

test_test395

robert_scott_jr_ said:

Hello and welcome. Although you've achieved the part with the thickness you desire, perhaps you'd like a cleaner, smoother look. Take a look at a version of your document; a bit complicated but resulting in what may be a more desirable part. - Scotty

https://cad.onshape.com/documents/86d2f43d26c4f4be42471e4b/w/c26425d30cf0470651179909/e/05ef70c90a1a66db6e309e97

john_lopez363 said:

@test_test395...  this is a very simple fix.   For Lofts to perform smoothly it usually help that if both Loft profiles have the same number of points defined. If they do not Loft will try to figure it out on it's own, and will sometimes guess wrong.

To fix this simply add a "Point" onto the circle sketch that is generally in a location where you'd expect the intersection of the Loft to occur.  Then when creating the Loft use the "Connections" function to define a connection between the Point on the circle sketch and a corresponding Point on the Rectangle sketch.

Test this by clicking the Connections function on your original Loft and you will see how wonky the connections are when not controlled.  By the way, this is also how you purposely twist a Loft if that is what you wanted.

 

Gentlemen, thank you very much!! That is a work of art, Robert! Thanks again for the explanation John, I'll use Robert's model and modify it with your info. Many thanks again