Welcome to 3DCADForums

Join our CAD community forums where over 25,000 users interact to solve day to day problems and share ideas. We encourage you to visit, invite you to participate and look forward to your input and opinions. Acrobat 3D, AutoCAD, Catia, Inventor, IronCAD, Creo, Pro/ENGINEER, Solid Edge, SolidWorks, and others.

Register Log in

Why fillet does opposite to my order


First of all, I myself know, I created this shape out of engineering rules!

However, please note the pictures and enlighten me, why fillet is done reversely?



Super Moderator
There's not a lot of information to go by. Which fillet tool, and which options did you use?

(my guess is the tangent support surfaces were not trimmed)
Last edited:


I either used "fillet between two surfaces" and also "chordal fillet"; both have the same effect and fillet is done reversely with an edge ( along with two parallel patch). Of course after I deactivated trim 1 and 2. When the trims are active nothing happens except some error messages.


New member
Can you make a section layed down on the edge you wanted to fillet? I think there are 2 surfaces actually folded close together. Or you can also save a stp or igs file here and let us check it. It should behave the same way on any PC.


Hi Bouta

I deleted the folded surfaces but the result was the same. After working a lot it made me tired because I think the shaping was wrong from its starting point with a series of unprincipled pieces. this caused that it turns into Frankenstein! As it made me confused like a complicated puzzle I had to delete it completely and started a new one carefully with regard to catia rules, though this one had a small failure as well ( width place of the front light and a wrinkled fillet near the place)

Thank you for your guidance :)
Hello Mans,

There are several solutions for your problem.
1 - Use "Shape Fillet" with G2 mode and click on trim button for both side. It will give you a nice and smooth fillet, but this feature can be tricky, it does not always work depending of your shape.
2 - Use parallel curve, split and blend. This method is a bit more manual and heavy to use, but it work most of the time.
3 - Same as 2- except that your sketch the curve and you project it on the surface. Takes even more time, but works.

This tutorial could be useful for you to learn more about GSD: https://youtu.be/e1Zu0GS3Y28

Good luck


Thank you PLM for your helpful advises. I deleted the shape inevitably but if I encounter the same problem next time, I will use your instruction certainly