[MrBasse]

We had 6 harbor freight wheels mounted and running and had no problem with turning with a 1/4" drop. We had planned on articulating the center wheels to allow for a stable shooting platform, but when we built the whole thing it turned out to be a little heavy.

We are now running two of our pneumatic wheels in the center and 2011 kop wheels front and rear. Looks like it should be about the same performance, but it doesn't look as mean. Plus it weighs 40 lbs less, which is good if we want to attach anything that can do minor tasks like perhaps picking up an 8" foam ball and shooting it.