So I just recently discovered Sketchup, and after going through a short period of various excitement (This is a cool program...time to try something serious...I'm going to ram my fist through the screen...oh that's how you do it...this is actually fun), I've built the beginning of a mech. I'm satisfied so far, but have a question. On the circled planes, I wish to insert pieces extending outward to accommodate legs and arms. The problem is, I want them to be symmetrical on both sides. Is there any way I can add pieces to the opposing sides so they'll extend out symmetrically?