After the failure of the front castor wheels in the last testing, we replaced the wheels with a much stronger brand of wheel. The new wheels are welded in two spots separated by a distance so that they can resist a moment caused by potential side loading. The QC2 tests these new castors, and we experiment with front/rear wheel drive. We ultimately decided to keep the rear wheel drive because otherwise the transaxle would take the brunt of the forces. We believe we can mitigate the front wheel issues by widening the distance between the wheels so that the driver can more easily see the wheels, and so that the wheels will not collide. Finally, we are going to add a tension member that holds the transaxle frame a bit more square. I have attached a video below!