Bisect makes model non manifold

I’ve been working on 3d printing a model for several weeks now and have made strides in remedying issues with the model, specifically manifold issues. I’ve encountered an issue I haven’t been able to overcome specifically as it relates to one aspect of the model. There is a piece that is rather thin that I’ve attempted to strengthen that area and, in that attempt, to increase the external area so it would print better. I used bisect on the faces behind the piece and created new faces. I was able to solve some of the manifold issues, but at this point I am stumped. I’ve read every post I can find and I think I’ve come to the limits of my knowledge of how blender operates and what I know to look for.

I know it has something to do with my execution.

Regarding the 3D printing angle, I have had good results printing, just trying to find tune the geometry so all aspects of the model are sliced correctly.

I think you should post some screenshots, because it is not clear what the actual problem is. If you’re talking about “bisect” tool then this tool just creates the line of vertices along a plane. If you need to split mesh along these vertices just ctrl+E -> edge split, “L” to select linked and detach them, fill open holes with “F”. I’m not sure what the problem is. I never did any 3d printing so i can’t tell what is required for this, but if you post some pictures maybe someone else could help.


Can you post a .blend file of THE PORTION of your mesh you want help with/a fix? I am not asking you to share your entire file with us.

I am somewhat familiar with the requirements for 3d printing, can def check if it is manifold or not.

Thank you for your response. I am pretty novice at this with 3d printing being my introduction. With intersecting faces, the program that creates the path of the printer has trouble reading the exterior of a model. I was attempting to remove as many intersecting faces as possible, especially where they haven’t printed correctly in the past.

Thanks for your help! I can get aspects of it manifold, but the intersecting faces are giving the slicer fits. The current non-manifold areas (aside from the obvious top and bottom of the torso) are where I tried to remedy the intersecting faces on a portion of the model that wouldn’t print appropriately.

Here is the portion of the model:

Here is the result of my most successful recent print so you can see the piece missing:

Oof. Have you tried looking at your model with mesh analysis checked and then turn on intersect? A bit of a mess… I’ll see what I can do.

This mp4 should show you the problem areas

Yeah… I’ll recommend that if it can’t be remeshed it probably won’t print properly. You have a lot of bad intersections. No fast way to clean them up.