Moving a physics button with fixed axis after rotation in Unity

Question

I'm trying to make a physics based button as shown below.

The red cube should travel down on the Y axis when force is applied and hit the trigger (the light grey box).

I have achieved this by making the red cube a rigidbody and freezing rotation and position (except on Y axis). The red cube is attached to the trigger via a sprint joint.

This works pretty well, until I try to rotate the whole container for the button, and then the button depresses on the world Y axis (red arrow below) instead of it's local Y axis (green arrow below).

How can I fix this? Thanks!

Answer 1

Figured it out, this code will restrict movement to the local y axis only and remove the freeze position flags on the rigidbody component

void Update()
{
    transform.localPosition = new Vector3(0, transform.localPosition.y, 0);
}