Diagnosing A Physical Error

The above image shows how at long distance the purple counterweight in this construction is not able to lift the wheel upwards.

This image shows how in this construction at shorter distance the purple counterweight is not able to lift the wheel upwards.

This third image shows how at very short distance the purple counterweight in this construction is not able to lift the wheel upwards.

The first device does not show an ability to return the wheel downwards again, even after a failed upward motion, indicating the counterweight could not be allowed to be heavier. This will become significant later.

However, in a different model called natural torque, bending the support stick a certain way results in clear upward motion (shown above). This may be a sign for example of different weight and leverage properties, significantly different design, or inconsistent physics. However, since the design and weight are not much different, it is thought to be inconsistent physics. The mechanical operation normally would be very similar, although in this case the leverage and weight properties are reversed (which should have a similar effect, but different distances).

Above: Natural torque (not the first device) shows proneness for the wheel to return downwards in spite of the automatic upward motion, unlike the other, very similar design.

The major difference I could find is the different more complex fulcrum mounting on the natural torque, however, this alone did not seem to make all the difference.