problem with extrude tool

Question

My skill are very limited with blender, however I need to print a tool but can't seem to make it properly on blender

This is my initial object, but I need to add a additional layer (finer) on the top so it look a bit like the second pictures :

I tried to select the edge and extrude them which seems fine and then select the faces that I just extruded and extrude them in X so it can be a few mm thick (for printing)

but that doesn't work and it make something like this

I also tried to created a duplicate of the first object and change the dimension on X/Y but it's change complete the angle of the object

Blender file

Answer 1

If I understand correctly what you want (?), you can:

• Create an new edge loop:

• Select the faces:

• Extrude up:

Answer 2

For most of the faces, using "Extrude Along Normals" works. Something about the geometry of the long face in the second quadrant (postive X value, negative Y value) is messed up though--you might want to just edit it manually there.

Quick note: choosing this option will mean you have two sets of faces (one for the top surface of the bigger bottom part of the shape, and one for the bottom part of the side faces you just extruded)! I can imagine this might be a problem for a 3D-print, although I have no experience in that area, so I can't say for sure.

Answer 3

The "how to fix" is already given as answer.

Though, this is due to the fact that the mesh is non manifold (normals conflict).

You can reproduce it with this setting: a divided plane with inverted normal on a side.

And your mesh is in the same situation: