I had accidentally pushed it off the sawhorse by then and the other 3 wheels were on the ground - would that make a difference in how the object behaves once another wheel is attached? I built the first crosspiece in dynamic mode, and everything wobbled and re-balanced dynamically as I attached other parts, but when I put the 4th wheel on it seemed to go static again. (Pics 1, 2) I have NO IDEA if dragging it uphill is going to work, though. Update: I've built the cart and loaded it with lumber.
