Extend surface creates open edges

i need help with my model. i am trying to extend the surfaces of the big body towards the surface which is next to it. But when i try to extend it it creates a lot of open edges or i can not extend the surfaces at all.
I have also tried to duplicate the edges and than lofting them but that creates a hard edge within the body which i want to avoid. also i want to do a fillet on the other side of 1 mm but i only manage to get one of max 0.5 mm .
Looking forward to your suggestions.
Qustion_extension.3dm (433.3 KB)

so i found out that i have to untrim the borders to be able to extend the edges. But than i still have the problem of the open edges. Do i have to rebuild the surfaces than ?

Hi Carlotta - you’ll need to re-trim the surfaces, I do not think there is any way to avoid that.


hej pascal,
yes i did that and it worked out !
do you have a suggestion how to blend the edges smoothly ? since they are quite steep and a blend of 1mm radius hasn’t worked out yet

Hi Carlotta - which ones? At the ends?


yes exactely
because it looks like this if i use the commend blend edges:

i probably have to rebuild those surfaces than as well, right ?
trim away the surfaces that are too long and rebuild them

Hi Carlotta - most likely, the radius is larger than the radius of the edges - it must be smaller, and at least 10X file tolerance.
Looking at one end of the part - these are the approximate minimum radii - you need to keep the radii of the BlendEdge or FilletEdge smaller.


ah fair enough
but how would you work than if you would want that 1mm fillet ?
maybe built up the surface differently ? i tried it with curves and than rail revolve but than the edges got to sharp

Hi Carlotta - I’d say the right way - not being the designer here, I don’t know what constraints you have - is to adjust the long transition surfaces to have 1mm + radius throughout at those locations.

Qustion_extension_maybe.3dm (346.3 KB)


amazing that worked out thank you so much!