True, the moment for the center of mass will probably be in the battery level, with the 6 oz LIDAR and the 4 oz BeeDo character on the top.
There is delicate balance between minimizing the weight on the castor and the maximum negative acceleration (stopping forward motion or starting reverse motion).
But then it is also possible to fix a face plant:
Also true. I was limited to the standoffs of the GPG3 Core Kit plus the extra Body Kit I purchased. The battery layer worked best with the shorter standoff, but that made the LIDAR layer huge.
The servo hits the LIDAR layer plate at +/- 70 degrees but I can live with that. I would have to trim off some of the left and right eyes to get 90 degrees, but since it is a multi-layer pc board, I don’t want to risk ruining $30.
Yes, that will be a good learning task to get create the URDF for ROSbot. Looking forward to that.