Has anyone got any example code for these sorts of systems (i.e. two or more masses connected via springs)? From the ODE documentation:
If you have a spring constant kp and damping constant kd, then the corresponding ODE constants are:
ERP = h kp / (h kp + kd)
CFM = 1 / (h kp + kd)
where h is the stepsize. These values will give the same effect as a spring-and-damper system simulated with implicit first order integration.
Being lazy I thought maybe I could take a look at how someone else has done this in jme rather than doing all the research myself… 
Springs are fun and also hard to do properly due to time step considerations and so forth. Take a look at Spring, SpringSystem and SpringNode in com.jme.math for some examples. These are done using the well known "Hitman physics" algs.
thanks, I’ll take a look. I was actually hoping for something using ode/jme physics as that would probably make interaction with the rest of the physics engine easier.