I enjoyed making the center foot on my R2 unit and this one has been the same. I still have to add a bit more detail around the skirt of the foot and create a pannel to cover the ankle bolt hole, but on the whole the foot in nearly their. It is heavily reinforced inside as I found that the R2 foot I made before got broken easily with people either standing on it or it hitting things. This one is much, much stronger. I have also gone with a much larger center wheel with better bearings which should cope with most surfaces.