Nice thoughts,

with out having a rolli in hand I am not sure where the center of gravity would be.. you would just have to concider that when putting an arm or items on front. but with the big payload area that is in the rolli , it would not be hard to make sure it was weighted and balance right.

Great Idea

hi

i dont think it weig very much.but its a good point to think off. the center off the robot is very important. i like the payload area,you can swits it whit a round one i think? its like a swinging radar.and there the jd ontop.oh yeach love it allreddy.

You could also do this with the servo that is used for JD'S head. It's a micro but more than strong enough. You would just have to work something out for the middle of the arm. It's a screw into another servo, but that could be modified pretty easily.

yes i think so to.the red mark below is a small gap to let the wires in. and out on part #18 ontop.

The front radar on the lower part is a great idea and frees up snap connections on top. Don't worry about the balance , a servo and ultrasonic there will not pose a problem , the chassis weights enough that it's not likely to tip forward. :)

thank you jstane1