Is there a way to do an expanding and contracting joint?

[IgorNadj]

E.g. I have two boxes, and a I want a joint between them which expands and contracts. Is there a way to do this? Within physijs or outside?

[mmmovania]

Use a point to point constraint as shown in this tutirial demo
https://github.com/mmmovania/Physijs_Tutorials/blob/master/SimpleJoint.html