hingeJoint.useMotor (script) not working at all on pinball flipper.

Not really enough information in your post to give you the solution to your problem, only things to check.

I presume 'hingeJoint' has been initialized with something like 'HingeJoint2D hingeJoint = GetComponent<HingeJoint2D>();' (c#)

Try checking what the motor is actually set to by reading the 'motor' property that returns a JointMotor2D structure. Not sure if you're setting these at runtime or not or just leaving the values to what you set in the editor.

Just trying to help here but note you can simplify the above script using something like:

'hingeJoint.useMotor = Input.GetKey ("o")

 

I just saw your post after I posted my reply. So yes, if that error is 'exactly' what is appearing then it looks like you're using the 3D hinge joint as that is named 'HingeJoint' whereas the 2D one is 'HingeJoint2D'.

 

Cool.

I would recommend that you set the reference to the HingeJoint2D to a variable rather than continuously looking it up like so:

var hinge : HingeJoint2D;

function Start ()
{
hinge = GetComponent (HingeJoint2D);
}

function Update ()
{
hinge.useMotor = Input.GetKey("o");
}

Even better, use C# instead

 

The language choice is a personal preference. If you come from a JavaScript background then you'll obviously feel more comfy using it however internally at Unity we're using C# and it's become the primary language of choice. Indeed, you'll see all tutorials and documentation written using it.

 

Have fun!