I’m very impressed with your “Dual Drive” design. It strikes a nice balance between mobility (turning easily) and defense (raw pushing power and straight tracking) without too much added complexity.
Looking at the CAD model, it wasn’t clear to me how the chain on the articulating wheels are tensioned. I’m assuming the assembly pivots about the spacer that rests in the slot in the frame, but I don’t see where a cam could be used to slide the assembly over and tighten the chain. Or do you use another method with these wheels?
About the cams, how are they fixed in place? Is the center hole tapped? Do they ever work their way loose?
This may be a minor detail, but the wheel bearing flanges are mounted to the frame with 1/2" slots, and the shaft is the same diameter. Wouldn’t it rub?
On the arm pivot, is the split shaft collar welded to the side plate? Is this to facilitate assembly?
Is small green arm on the main arm pivot for counterbalancing purposes?
Once again, nice work, and thank you for sharing.