4 ms·
> Getting dragged sideways both wears flat spots in the wheels and it can bend the castors or pop the soft part of the wheel of its rim. This may be an America
by dTal 3y ago
> Getting dragged sideways both wears flat spots in the wheels and it can bend the castors or pop the soft part of the wheel of its rim.
This may be an American problem. In the UK and many European countries, shopping carts ("trolleys") have castors on all four wheels; they will quite happily glide sideways. This makes them more maneuverable in the smaller stores, at the cost of being more difficult to control - more like the ship in Asteroids than a go-kart.
- pixl97 3y agoYa a few places have these in the states, but as you say the control issues are problematic. The whole, an object in motion stays in motion tends to mean if you're pushing one of these heavy carts and try to turn it will rotate about its own axis rather than make a corner.
- dTal 3y agoI have actually come to prefer the all-castoring design. It requires more skill, but less force and the acheivable performance is superior. To turn a cart with fixed wheels, you must apply torque to the push bar. As well as being too narrow to give good leverage, the cart is quite dynamically stable and so resists this torque, so you must slow down or tolerate a wide turning radius. To turn a fully castored cart, you apply physics - all you have to do is orient the cart so that is pointed sideways, then push hard. The key is then to maintain the cart pointing 90 degrees to the direction of travel throughout the turn, so that you can oppose centripetal force merely by pushing - no torque required. When the turn is complete, simply stop pushing. The cart will at this point still be oriented sideways of course, but you can correct this easily at your leisure.