Extrude In (also join and seperate faces)

I’ve been able to select a face on the starting cube in edit mode and extrude it out, but how do you extrude it in and also get rid of the border that forms?

how do i join two or more parallel and flush faces so that they become one face, and how do i choose exactly where to divide a face?

I would like exact hotkey button presses / menus selections please.
that’s all for now.

thx,
SupLuiKir

Welcome to BA forums!

If I understand you correctly, you basically want to shorten the cube. Extruding makes a new section, when you actually want to get rid of the section. The easiest way to do that is to select your face, and press the “g” key on your keyboard and then tap the “z” key to constrain along the Z axis (or x or y axis respectively) This will shorten your cube and move that face without leaving a border.

Extruding inwards with a cube causes certain problems, because your edges get connected in ways which I can’t explain well.

it works. I mean of course it works. thx a lot! ^-^

now I still need help dividing and joining edges at exact places. whenever i use spacebar=>edit=>edges=>subdivide the polygons get all screwy and i can’t choose how I want the faces subdivided. what I mean is the face automatically gets separated into 4 squares and the joining faces get separated into 3 triangles. I really don’t know how to change what edges there are without affecting other edges. what I want is a way to divide the cube’s side faces in half to create “lego man arms.” of some sort with an extrusion.

Any help appreciated,
SupLuiKir