[ODE] Joint Question

[David Wilkie]

I'm trying to simulate a "pin joint".  In this scenario, one body has
a hole through which another body spins:  this is shown below in an
exquisite ASCII figure.
           ___________
          /   ____   /   /
         /   /     /  /   /
      ********/  /   /*****
       /   -----  /   /
      /---------/--/

The line of stars should rotate around the central axis running
through its length.  The rectangular torus should not be transformed
by this rotation.

I tried implementing this with a hinge joint, but there is no anchor
point between the bodies.  The only joint type that does not require
an anchor point is the slider joint, which allows a degree of
translational freedom instead of rotational freedom.

I'm worried that simply letting the line of stars spin in the torus
without a joint, i.e. keeping it in place with only contacts, will be
very computationally expensive and less physically accurate.

Does anyone have any suggestions for simulating this kind of scenario?

-David Wilkie