Gustavoeb, I agree hitting the plus key would give some undesired results on some of the geometry but good thing this is a wip. Your links will prove useful in most cases. I would like to add http://www.thegnomonworkshop.com/store/product/949/3D-Design-for-Production For those of you who don't know....

More wireframes.

Hi everyone, this is a study in hard surface modeling.
Not the most original subject but proves challenging for me.
Any of your comments are welcome.