The damage discussed here would happen only in an extreme situation where someone pushed in the wheel of a Vernier Dynamics Cart and then quickly released it to cause a loud click. This can break the plastic that holds the axle in position. We have found that, in these cases, it is possible to repair the cart by clamping the axle down and out of the way and then using epoxy cement to glue the pin in position as shown in the photo attached.

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The axle mounting is different on the Vernier Sensor Carts and Motion Encoder Carts. The information above does not apply to these carts.